[Substation Installation]
[From the U.S. Government Publishing Office, www.gpo.gov]
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WAR DEPARTMENT TECHNICAL MANUAL
NON-CIRCULATING
SUBSTATION
INSTALLATION
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WAR DEPARTMENT • 30 JUNE 1944
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H’A R DEPARTMENT TECHNICAL MANUAL T M 11-474
SUBSTATION
INSTALLATION
WAR DEPARTMENT
30 JUNE 19 44
United States Government Printing Office Washington : 1944
WAR DEPARTMENT, Washington 25, D. C., 30 June 1944.
TM 11-474, Substation Installation, is published for the information and guidance of all concerned.
[A.G. 300.7 (12 May 44).]
By order of the Secretary of War:
G. C. MARSHALL, Chief of Staff. Official :
J. A. ULIO,
Major General,
The Adjutant General.
Distribution :
As prescribed in paragraph 9a, FM 21-6: Armies (2); Corps (2); Sv C (25); Dept (1); Def Comd (1); I Bn 11 (2); IC 11 and 44 (5); Air Sv C (10); AF (5); AF Dep (10); Sig C Lab (5) ■ P/E (50); ASF Dep (5); Sig C Dep (10); Sig C Rep Shs (10); Sig C Inspection Zones (5); Sig C Procurement Dist (5); Post, Camp Sta (1).
I Bn 11: T/O and E 11-15, Sig Bn; 11-25, Sig L Cons Bn; 11-85S, Armd Sig Bn; T/O 11-95, Sig Opn Bn; 11-500 Sig Sv Bn; 11-225, Sig Cons Bn, Avn; 11-335, Sig Bn (Grd-Air Sup Comd); 11-415, Sig Plotting Bn, AW Regt.
IC 11: T/O and E 11-18, Fid Opn Co, Sig Bn; 11-27, Sig L Cons Co; 11-88-S, Opn Co, Armd Sig Bn; 11-89-S, Cons Co, Armd Sig Bn; 11-257, Sig Co, Tr Carr Wg; 11-460-1S, Sig Hqs Co, AWS, Ftr Comd; 11-547, Sig Ctr Team; 11-587, Sig Base Maint Co; T/O 11-97, Sig Opn Co; 11-127, Sig Rep Co; 11-137, Sig Instl Co; 11-217, Sig Co Avn; 11-227, Sig Hv Cons Co, Avn; 11-237 Sig Co, Sv Gp; 11-247 Sig Co Wg; 11-267, Sig Co, AF; 11-277, Sig L Cons Co, Avn; 11-287, Sig Co, Dep Avn; 11-300-1, Hqs Sig Sv GHQ; 11-400, Sig AW Org; 11-412, Hq & Hq Co Sig AW Regt; 11-537S, Sig Co, Engr Sp Brig; 11-107, Sig Dep Co; 11-327, Sig Port Sv Co.
IC 44: Hq & Hq Btry, AAA Comd (HAW).
For explanation of symbols see FM 21-6.
II
CONTENTS
SECTION I.
II.
III.
IV.
V.
VI.
Paragraph Page
Purpose.......................................... 1 1
Scope.............................................. 2 1
Terminology........................................ 3 1
Types and uses of wire............................. 4 2
Handling drop wire................................. 5 4
Splicing drop wire.............j................... 6 5
OUTSIDE INSTALLATION.
Drop wire clamps and clips......................... 7 9
Equipping and installing attachments............... 8 11
Tying parallel drop wire........................... 9 30
Tying twisted-pair drop wire...................... 10 32
Wiring at cable terminals......................... 11 34
Clearances for aerial plant....................... 12 44
Drop wire runs from poles......................... 13 53
Drop wire runs on buildings....................... 14 58
Block wire runs................................... 15 62
STATION PROTECTION.
Station protectors................................ 16 67
Protector grounds................................. 17 68
INSIDE INSTALLATION.
Building entrances............................... 18 73
Selection of wire................................. 19 78
Minimum clearances and protection................. 20 78
Passing wire through floors and walls............. 21 81
Wiring distributing systems....................... 22 81
Connecting blocks................................. 23 84
Locating and mounting telephone sets.............. 24 85
Fastening and terminating wires at subscriber sets. ... 25 90
Testing........................................... 26 90
STATION WIRING PLANS.
Description and use............................... 27 92
Limitations..................................... 28 92
Definitions....................................... 29 92
Station designation............................... 30 92
Specific station wiring plans..................... 31 93
Keys.............................................. 32 93
SPECIAL EQUIPMENT.
Explosion-proof telephone......................... 33 95
Outdoor telephones................................ 34 96
Loud-ringing bells................................ 35 96
III
SECTION VII. SUPPLEMENTARY DATA.
Tools..................
Materials..............
Paragraph Page . . . 36 98
. . . 37 99
APPENDIX. REVIEW QUESTIONS ......................
101
DESTRUCTION NOTICE
WHY—To prevent the enemy from using or salvaging this equipment for his benefit.
WHEN—When ordered by your commander.
HOW—1. Smash—Use sledges, axes, handaxes, pickaxes, hammers, crowbars, heavy tools, etc.
2. Cut—Use axes, handaxes, machetes, etc.
3. Burn—Use gasoline, kerosene, oil, flame throwers, incendiary grenades, etc.
4. Explosives—Use firearms, grenades, TNT, etc.
5. Disposal—Bury in slit trenches, fox holes, other holes. Throw in streams. Scatter.
USE ANYTHING IMMEDIATELY AVAILABLE FOR DESTRUCTION OF THIS EQUIPMENT.
WHAT—1. Smash—Terminal blocks, telephones, bell boxes, keys, protectors, connecting blocks, and insulators.
2. Cut—Cable, wire, and cords.
3. Burn—Cable, wire, and cords.
4. Bury or scatter—Any or all of the above pieces after destroying them.
DESTROY EVERYTHING
IV
SECTION I
GENERAL
1. Purpose
The purpose of this publication is to provide a reference manual of methods and practices used in the installation and maintenance of telephone substations.
2. Scope
It is impractical to include in this manual information covering all the conditions that are encountered by a substation installer; therefore, only those methods and practices in common use are covered. The material is presented under seven section headings: General, Outside Installation, Station Protection, Inside Installation, Station Wiring-Plans, Special Equipment, and Supplementary Data. Appropriate Bell System Practices have been used in the preparation of this manual.
3. Terminology
Common terms and their definitions follow:
a. Aerial. Cable or wire construction suspended above the ground surface.
b. Armor. Additional outer wire and jute wrappings on some types of cable, affording mechanical strength and protection from the effects of abrasion.
c. Bare. Not insulated.
d. Bridge. Connect across.
e. B.S.P. Bell System Practices.
/. Block Wire Run. Parallel distribution consisting of two or more pairs, usually drop or bridle wire, suspended from a suspension strand in bridle rings, or cable rings. Used mostly in warehouse areas and similar installations at army posts.
g. Braid. The woven outer covering of drop wire, inside house wire, bridle wire, cross-connecting wire, and instrument wire, which affords protection to insulation.
h. Buried Cable. Construction where the earth is in direct contact with the outer surface of the cable.
i. Cable. Wires separately insulated which are paired in a common covering or sheath. The insulation and covering vary according to the type of cable. Cable pairs that are exposed to dampness of the atmosphere are usually covered with impregnated silk and cotton insulation. Cable used in aerial and underground construction requires only paper insulation for each individual conductor. A lead sheath overall provides waterproof covering. Buried and submarine cables have additional armor and jute wrappings to protect the lead sheath from physical injury. Rubber-covered cables of 5 and 10 pairs have been developed for temporary and semipermanent installation in wire communication systems.
j. Cable Pair. Two insulated wires, twisted together, which form
1
the two sides of an intended electrical circuit, and are often included with other pairs within a cable sheath.
k. Cable Terminal. Equipment used to terminate cable pairs, permitting access for cross-connecting, testing, and making service connections.
I. Cross-connection. Physical and electrical connection of two circuits which have been terminated to provide flexibility in the plant. The circuit may be fused or not where cross-connected. Cross-connection also provides a test point at which the cable may be sectional-ized to determine the location of trouble.
m. Drop Wire. The pair of wires used to complete the circuit between the cable terminal and the subscriber’s premises, -when this section of the circuit is subjected to the effects of weather.
n. Exposed. A circuit that is vulnerable to high voltage or lightning.
o. FX. Fused cross-connection.
p. Ground Wire. A special, low-resistance copper wire which forms the metallic link between the ground post of the protector and ground clamp or ground rod.
q. House (Inside) Wire. Two or three conductors twisted together and used to connect the subscriber’s telephone to the protector. House (inside) wire is not intended for wet runs and should not be subjected to tensile strain. The insulation will not stand severe abrasion.
r. Insulation. A nonconducting material used to cover or separate electrical conductors. Rubber, glass, bakelite, paper, silk, cotton, and air are the nonconductors most commonly used.
s. Jumper. A piece of wire used to cross-connect.
t. Key. A switch used to close an electrical circuit.
u. Loading Area. A section of the country; designated light, medium or heavy, according to weather severity. Wind, rain, sleet, ice, and snow are the principal factors involved in determining the classification of an area.
v. Protector. A device used to protect inside and outside telephone plant facilities from excessive voltage or current.
w. Subset (Bell Box). A telephone ringer and induction coil inclosed in a box.
x. Substation (Subscriber’s Station). A complete telephone installation on a subscriber’s station.
y. Telephone Instrument. Subscriber’s handset, desk set, or combination set.
4. Types and Uses of Wire
a. Drop Wire. (1) Wire W-38 is a twisted-pair drop wire, with solid No. 17 B.&S. gauge, copper-clad, steel conductors which are separately insulated with a tough rubber compound and covered by an asphalt-impregnated, weather-proof, cotton braid. The tracer wire is designated by a raised thread which is woven into the braid of one conductor.
(2) Wire W-50 is similar to Wire W-38, but the conductors are No. 14 B.&S. gauge, solid, hard-drawn copper. Designation of tracer wire is the same as for Wire W-38.
(3) Wire W—108 is a two-conductor, parallel drop wire, having solid bronze or copper-clad steel conductors of 0.045 inch diameter or No. 17 B.&S, gauge wire, separately insulated with a rubber compound.
2
Both conductors are encased in an asphalt-impregnated, weatherproof, cotton braid. The tracer is identified by a straight moulded ridge in the rubber insulation on one conductor. Wire W-108 will not withstand excessive abrasive action.
(4) Wire W-108-A is a modification of Wire W-108. The conductors are slightly smaller than conductors of Wire W-108, being No. 18 B.&S. gauge, of solid bronze or copper-clad steel.
(5) Commercial parallel drop wires are designated BR, TR, BP, or TP. . Use BP or TP type for normal runs. BR and TR types have a heavier braid and slightly heavier rubber insulation on the individual conductors.. They are intended for use where drops are subjected to light abrasive action due to rubbing against foliage and branches % inch or less in diameter.
(6) Drop wire should be used in the following places:
(a) Span between poles.
(b) Pole to building.
(c) Open wire to protector.
(d) Terminal to protector.
b. Ground Wire. (1) Wire W-119 has a single No. 12 B.&S. gauge, solid, tinned-copper conductor, and is insulated with a rubber compound and flameproof, weatherproof braid. Wire W-119 will accommodate four or five protectors.
(2) No. 14 B.&S. gauge ground wire is similar to Wire W-119, but has no Signal Corps type number. No. 14 B.&S. gauge ground wire will accommodate one to three protectors.
c. Inside House Wire. (1) Wire W-33 is a two-conductor, twistedpair inside house wire. Each conductor is separately insulated with a rubber compound and green cotton braid. The conductors are solid, No. 19 B.&S. gauge, tinned copper. The tracer wire is designated by a red thread in the braid. Wire W—33 is used inside buildings where moisture will not be encountered.
(2) Wire W-117 is a two-conductor, twisted-pair, inside house wire. Each conductor is No. 22 B.&S. gauge, solid, soft, tinned copper wire, separately, insulated with a rubber compound, and covered with a green cotton braid. Wire W—117 may be used as a substitute for Wire W-33.
(3) Wire W-118 is a three-conductor twisted wire; each conductor is a solid, soft, tinned copper wire, No. 22 B.&S. gauge. Each conductor is insulated with a rubber compound and protected with a green cotton braid. The tracer for identification is a red or yellow thread in the braid of two conductors; the third conductor is covered with a green braid.
(4) War Production Board (WPB) special wire is, at present, the only commercially manufactured wire procurable (as authorized by the War Production Board) for commercial telephone company use. WPB special wire is a twisted-pair, two-conductor wire; each conductor is a solid, soft, tinned copper wire, No. 22 B.&S. gauge. Each conductor of WPB special wire is separately insulated with a rubber compound, and both conductors are covered with a brown cotton braid, giving the appearance of a single conductor unless examined closely" The tracer is a raised ridge on the rubber insulation of one conductor. WPB special wire is a permissible substitute for inside house Wire W—33.
d. Duct Wire. Duct wire is a commercial product having no Signal
3
Corps equivalent. Duct wire is a twisted-pair, two-conductor wire; each conductor is a solid No. 22 B.&S. gauge, soft, tinned copper wire. Each conductor is separately insulated with a rubber compound, and over the rubber insulation is a tightly wrapped jacket of paper which is impregnated with a sealing and waterproofing compound. The ring tracer is a red thread, and the tip tracer is a green thread. Duct wire is designed especially for use where dampness is evident or probable, as in conduits, ducts, or damp cellars. Being weatherproof, duct wire may be used for cross-connecting open wire pairs, connecting outdoor connecting blocks to cable terminals, or connecting outdoor protector mountings to line or cable terminals. Duct wire should never be subjected to abrasion because of its paper covering.
e. Bridle Wire. Wire W-69-A is a twisted, two-conductor wire; each conductor is a solid, soft, No. 22 B.&S. gauge, tinned copper wire. Each conductor is separately insulated with a rubber compound and wrapped in a black cotton, weatherproof braid. The tracer designation is either a raised ridge on the rubber insulation of one conductor or a raised thread in the cotton braid of one conductor. Wire W-69-A is used extensively in damp, inside runs such as cellars or under buildings. Wire W-69-A may be used for cross-connecting at outdoor terminals, between outdoor protectors and terminals or open wire, and will withstand considerable abrasive action. Wire W-69-A is also suitable for use in duct or conduit runs.
f. General Purpose. Bell System GN station wire, a commercial type of wire having no Signal Corps equivalent, is a twisted pair of two conductors; each conductor is a solid, soft, No. 22 B.&S. gauge, tinned copper wire. Each conductor is separately insulated with a rubber compound and is covered with a cotton braid. The tracer consists of a red thread woven in the braid of one conductor. Bell System GN station wire is obtainable in either brown or ivory color, and offers an inconspicuous installation against colored backgrounds. Bell System GN station wire may be used in damp locations, but will not withstand wet conditions. Under most conditions, Bell System GN station wire may be substituted for either inside wire or bridle wire.
5. Handling Drop Wire
a. Care. When transporting drop wire in vehicles do not allow the wire to be damaged by tools and equipment. Do not trample the drop wire, or allow vehicles to run over it. When uncoiling drop wire do not allow kinks to develop. When not using a drop wire reel, kinks in the wire can usually be avoided by reversing the coil every five or six turns. If a kink does develop, and is pulled tight, cut the kink out of the wire.
b. Drop Wire Reels. Drop wire reels are provided to facilitate the installation and recovery of drop wire. A drop wire reel wifi accommodate coils of wire having an inside diameter of about 15 inches. A coil of wire is placed on a drop wire reel by removing the side of the reel, and placing the coil on the hub and against the other side of the reel. The removed side is then replaced. If coils of wire having an inside diameter of more than 15 inches are to be used, the wire must first be rewound on the drop wire reel. The weight of wire coiled on one reel should never exceed 50 pounds.
4
6. Splicing Drop Wire
a. General. When splicing drop wire in the field, the following rules must be observed:
(1) Do not nick the conductor when removing the insulation.
(2) Clean the wire thoroughly before making the splice.
(3) Splice tracer wire to tracer «wire, and plain wire to plain wire.
(4) Make the splice mechanically secure, and make a good electrical connection.
(5) Check to see that the tension on the completed splice is equal on both conductors.
(6) Make the splice as neat as possible.
b. Double-sleeve Splice. A double sleeve consists of two parallel, soft metal tubes soldered together. The size of sleeve to be used and the method of splicing appears below.
(1) Remove 12 inches of braid from each pair of wires to be spliced.
(2) Cut one wire of each pair 6 inches shorter than the other wire of that pair. (Cut the plain wire of one pair, and the tracer wire of the other pair.)
(3) Remove about 4 inches .of the rubber insulation from all the conductors, and clean the conductors thoroughly.
(4) Place the double sleeve over the end of one wire of one pair and insert the corresponding wire of the other pair. Bend the projecting ends of the wires slightly to keep the sleeve and the wires in place.
(5) Grip opposite ends of one sleeve of the pair with sleeve twisters (Clamp LC-24), or pliers which have grooves to fit the sleeve.
(6) Give the sleeve five half-turns, twisting from both ends.
(7) Wrap each projecting end of the bare wire around the insulated portion of the wire in the direction in which it tended to wrap when the sleeve was twisted.
__________________________ln-
3 Complete Turns f /
5 Half Turns \
*— 1/4 in.
TL-9284
Press down end
Figure 1. Twisted double-sleeve splice.
(8) Cover the joint with two wrappings of 34-inch rubber tape. Start at the center; wrap 1 inch beyond the last turn of wire on one end; reverse direction and wrap 1 inch beyond last turn of wire on the opposite end; reverse direction once more, and complete the wrapping at the center of the splice. Roll the completed joint between the fingers to bind the tape more firmly together.
(9) Repeat the operations described in (4) to (8) above with the remaining two wires.
(10) Wrap the entire splice with two layers of 34-inch black friction tape to a point % inch beyond the edge of the rubber tape. (Apply black friction tape in the same manner that the rubber tape was applied, as described in (8) above.)
5
Table I. Double-sleeve Splice
Wire to be spliced Size of sleeve (in.) Number of halfturns to be made in sleeve
Parallel drop wire to parallel drop wire. 0.045 5
Parallel drop wire to No. 20 bridle wire. 0.045x0.032 5
Parallel drop wire to No. 18 bridle wire. 0.045 5
No. 20 bridle wire to No. 20 bridle wire. 0.032 4
No. 20 bridle wire to No. 18 bridle wire. 0.045 x 0.032 5
c. Pressed-sleeve Splicing. (1) The precautions to be observed when making pressed-sleeve splices are the same as the precautions in a above
(2) Sleeves for pressed-sleeve splicing are of two types:
(a) “S”-type sleeves are single-tube sleeves which have a uniform diameter bore and an indentation at the midpoint of their lengths which regulates the distance to which the conductors are inserted. The sizes and types of wires for which “S”-type sleeves are intended are. given in table II.
Table II. “S” Brass Sleeves
Size (in.) Length (in.) Type of wire
0.032-0.025 1 Bridle wire (20-gauge). Wire W-69-A. Duct wire. WPB special wire. Wire W-117. Wire W-33. Bell System GN station wire.
0.045-0.040 TP and TR drop wires. BP and RB drop wires. Bridle wire. Wire W-108 and W-108-A. Wire W-38.
0.064 1% Wire W-50.
(b) Combination “S” sleeves are single-tube sleeves in which the bore diameter of one-half of the sleeve differs from the bore diameter of the other half. The sizes and types of wire for which combination “S” sleeves are intended are given in table III.
6
Table III. Combination “S” Sleeves
Size (in.) Length (in.) Types of wires
Large bore Small bore
0.045-0.040x 0.032. 1 TP and TR drop wire. . BP and BR drop wire. . Bridle wire Wire W-108 and W-108-A. Wire W-38 i Bridle wire (20-gauge). Wire W-69-A. Duct wire. WPB special wire. Wire W-117. Wire W-33. Bell System GN station wire.
0.064x0.045-0.040. 1% Wire W-50 TP and TR drop wires. BP and BR drop wires. Bridle wire. Wire W-108. Wire W-108-A. Wire W-38.
(3) The sleeve presser (No. 17-2, Nico press tool) is a hand-operated tool for pressing the single-tube sleeves used in splicing certain sizes of insulated wires and bare copper wires. The jaws of the sleeve presser have two grooves which accommodate the various sizes of sleeves.
(4) When making a pressed-sleeve splice, the correct size sleeve must be used, especially when two different sizes of wires are being joined. Proceed in the following manner:
(n) Remove the braid from the end of the parallel conductors for a distance equal to 1/4 times the length of the sleeve to be used. Separate the rubber-insulated conductors and remove the rubber insulation from the ends of the conductors for a distance equal to one-half the length of the sleeve to be used. If the wire to be spliced is a twisted pair, remove the braid and rubber insulation from the end of the conductors for a distance equal to one-half the length of the sleeve to be used. Clean the bare conductors thoroughly.
(b) Insert the proper sleeve on one of the conductors of one of the pairs to be spliced. _ Push the sleeve over the wire until the end of the sleeve touches the insulation.
(c) Crimp the sleeve on each side near the insulation with a pair of diagonal pliers, in order to hold the sleeve in place.
(cZ) Match the tracers and insert the proper conductor from the other pair into the sleeve, crimp the ends of the sleeve in order to hold the sleeve in place.
(e) Starting approximately 1/16 inch from the end of the sleeve, press the sleeve with the sleeve presser at equally spaced points on the s eeve, six times for the large sleeves, and four times for the smaller sleeves. (See fig. 2.)
(/) Wrap the joint with a single layer of 3/4-inch rubber (Commer
7
cial DR) tape, extending the tape 3/4 inch beyond each end of the sleeve.
(g) Repeat the above procedure with the remaining two wires.
(7i) Wrap the entire splice with two layers of 3/4-inch friction tape as described in b (8) above.
Note. If DR tape is not available prepare the wire for splicing as described in paragraph 6b(l) to (3).
,CRIMPED SLEEVE
/\\\ '—NO. 17*2
' lyA NICOPRESS
TL 6725 A \\ T00L-
Figure 2. Sleeve presser in use.
8
SECTION II
OUTSIDE INSTALLATION
7. Drop Wire Clamps and Clips
a. Installing Drop Wire Clamps. (1) Drop wire clamps consist of two parts—a. sleeve and a wedge. A copper wire loop is secured to the wedge and is used to attach the clamp to the point of support.
(2) When installing drop wire clamps, place copper wire loop over hook or knob, and pull tight.
(3) Place sleeve over wire to be secured, with narrow end of sleeve toward hook or knob.
(4) Place sleeve loosely over wedge, with wire between wedge and sleeve.
(5) Adjust slack by holding sleeve in place with thumb.
(6) Secure sleeve firmly against wedge. (See fig. 3.)
~ i. L ;___________________________________
111 TL-9200
Figure 3. Drop wire clamp installed.
b. Installing Snub R Grip. (1) The Snub R grip consists of a piece of grooved metal shaped to form a spiral. (See fig. 4.) At one end of the spiral a wire loop is attached which is placed over a knob or drop wire hook to mount the grip. Friction between the wire and the grip acts to hold the wire in place.
(2) When installing the snub R grip, place the wire loop over the supporting attachment. W ind the drop wire in the grooves of the grip starting from the side opposite the span, in order to prevent kinks from developing in the vertical run.
(3) Do not bend the projections at the ends of the spiral aaainst the wire.
9
Figure 4- Snub R grip installed in unexposed area.
c. Installing Drop Wire Clips. (1) Place wire in back of clip so that the flat surface of the wire lies on the bottom of the clip.
(2) Use pliers to grip the top side of the clip near the edge and the bottom side near the back, and press the top side of each section of the clip over the wire.
(3) Use pliers to grip the projection near the edge and bottom side of clip near the back, and press the projections of each section over the top side of the clip. (See fig. 6.)
(4) If brackets and knobs have been previously installed and are only partially filled, use knob adapters in the vacant grooves of the knobs, and place the drop wire clips over the knob adapters.
(5) At"corner attachments where there is a pull of more than 4 inches, use two drop wire clamps, dead-ending both ways. (Pull is defined as the distance measured as shown in fig. 5.)
Point of support;
Route of drop wire
Route of drop wire
TL-9257
Figure 5. Pull.
10
TL-9201
Figure 6. Installing drop wire clip.
8. Equipping and Installing Attachments
a. Anchoring Devices. (1) Hammer drive anchors consist of an expansion shield and a nail. The nail serves as a wedging element and is used in attaching fixtures to masonry surfaces. For maximum holding power the diameter of the drilled hole must be exactly the same as the diameter of the unexpanded shield, and deep enough to accommodate the full length of the nail. (See fig. 7.)
(2) Screw anchors consist of an expansion shield which is available in two general types: one to accommodate a wood-screw wedging element, and the other to accommodate a machine-screw wedging element. (See figs. 8 and 9.) Screw anchors are also intended for use in attaching fixtures to masonry surfaces.
11
? Cable Clamp
: WT'°rOther 'IXtUre
/Expansion Shield <
ta^»rliyg,_'2LLL^_..a -p-
Dryvin Anchor ’ ’
Jl Insert expansion shield through the
V 1 mounting hole of fixture and into
"" Nail drilled hole.
(Wedging Element)
'* a Diamond Hammer J
—Drive Anchor frUitd!
4 - WEayfimi m.r r • >5 ‘ ■'iSr=^
: ■ -■■/..■hl I Oft, .
/ v It 8in'
Place these rings so that W 1 wires will not touch cable--—1 —------------------t,
• JMi I Ill fol i'cT^I
All rings to be i ---
7/8 in. Drive Rings ~ I
1 1° M
4 in. • JI;
4 in. I ।
£______________Y! I i
TL-9206
Figure 13. Drive rings installed at cable terminal mounted on pole.
15
(a) Approximately 50 inches apart on horizontal runs.
(b) Where windows are available for attachments on vertical runs, make an attachment on each floor.
(c) Where windows are not available for attachments on vertical runs, space the attachments approximately 8 feet apart.
(7) Where wire run is horizontal, place drive rings so that the opening of the drive ring is at the top.
(8) In a wire run that changes direction from horizontal to vertical, place two drive rings at the bend of the run and arrange the drive rings so that the wires will rest against the loops and not against the pins of the rings.
(9) Where a wire run turns an outside corner, place a drive ring not farther than 6 inches away from the corner, in each direction, and cover all the wires that come in contact with the corner, with at least two layers of 3/4-inch black friction tape at the point of contact.
(10) Where a wire run turns an inside corner, place a drive ring not farther than 6 inches away from the corner in each direction.
(11) Where drive rings are installed at distribution terminals (figs. 13 and 14), use the 7/8-inch ring, which will provide facilities for wiring at 16-pair (and smaller) distributing terminals.
_______j i_________ ■ ■ n~
: n n JI!~
:=J= ww=w-
r. .-Jilt—g^UJb-JL
' I || WW JjjT
7/8 in. Drive ~\ I I
Rings \l
|< __)7 _J 5in-
4 in. ||
-----
-5: ' TL'9209
Figure 1^. Drive rings installed at cable terminal mounted on wall.
(12) For wiring under crossarms, use the 5/8-inch ring.
(13) Use 7/8-inch drive rings for wiring facilities in the rear of guardarms, and mount the drive rings directly above the lead holes
16
provided for bridle rings having wood-screw threads. Locate the drive ring 1 inch above the bottom of the arm.
(14) Wires should be laid in, not drawn through, the drive rings.
(15) Pull the wires tight, to avoid unsightly sag, but not tight enough to cause undue strain on the wires. When more than one pair of wires is in the rings, allow the same amount of sag in all wires, to present a neat appearance.
d. Equipping House Bracket with “S” Knobs. Equip house bracket with “S” knob as shown in figure 15.
Where one S Knob is required use 5/16 in.x 2 in. FH Stove Bolt
5/16 in. x 3 in. F H Stove Bolt
7/16 in. x 1 in. Washer under nut '
TL-9210
Figure 15. “S” knobs installed on house bracket.
e. Equipping House Bracket with “T” Knobs. Equip house bracket with “T” knobs as shown in figure 16.
f'/LZ 3/8inx5in.
ii lul Machine Bolt
111' ! , 7716 in.x 1 in. Washer
i' lll’l fe- under head and
1nut of bo,t-
3/8in.x 3 in. Machine Bolt.
7/16in.x 1 in. Washer under head of bolt
Figure 16. “T” knobs installed on house bracket.
17
f. Equipping Corner Bracket with “S” and “T” Knobs. Equip corner brackets with “S” or “T” knobs as shown in figure 17.
SXnob-x
F.H. Stove Bolt
Where two S Knobs are required use5/l6in.x 3 in. F.H. Stove Bolt and7/)6in.x 1 in. Washer under nut
3/8in. x 5 in.. Machine Bolt 7/bin x 1 in. Washer under head and nut of bolt
Where one T Knob is required use3/,8in.x.3 in. Machine Bolt. 7/l6in.x 1 in. Washer under head of bolt
TL-9212
Figure 17. “S” and “T” knobs installed on corner brackets.
g. Equipping Angle Screws with “S” and “T” Knobs. Equip angle screws with “S” or “T” knobs as shown in figure 18.
7/16 in. x lin.
7/l6in.x 1 in.^ [ Washer
Washer \ _1
) ^SKnob —TKnob
5/)6in.Angle Screw S 3/8in. Angle Screw -'y 1/9213
Figure 18. “S” and “T” knobs installed on angle screws.
h. Equipping Universal Insulator Supports with “S” and “T” Knobs. Equip universal insulator supports with “S” or “T” knobs as shown in figure 19.
18
No.505 Universal
Insulator Support
No.506 Universal
Insulator Support
S Knob may be qx
. attached to this I \ ^X )
X XQ) face °f suPP°rt JxXX X
/|XX when required. >C'' X||x s'""
J Mapped y
\5z X® 7^ for M Bridle /\
X/X Rings. 7 XX Z '®X I „ „,, „ 3/8 in. x 3 in. Machine Tapped S T Knob may be*
5/16 in. x 2 in. F.H. Stove Bolt. 7/16 in. x 1 in, holes for attached to this
Bolt. 7/16 in. x 1 in. Washer Washer under nut. M Bridle face of support
under nut. Rings when required.
TL-9214
Figure 19. “S” and “T” knobs installed on universal insulator support.
i. Installing “S” or “T” Knobs. (1) Attach “S” knobs to exposed frame portions of brick-veneer buildings, when practicable. A drop wire hook may be used instead of an “S” knob, provided that the hole can be drilled at the center of a brick without cracking the brick. To install an “S” knob on brick veneer, drill a 5/16-inch hole in the mortar between bricks in order to pass the wood screw through the brick portion of the wall.
19
Brick Veneer Stucco on Wood
■ in. #18 F H Galv.
Woodtow-
1 in. #18 FH Galv. ‘■S’ltW® W Wood Screw. :X?
Use 3 V2 in- *18
■ \ X Xi1 §0 F H Galv. Wood
' I I X.M X H Screw,if necessary
X,„ / $ & M to reach wood
® sheathins-
Wood Hollow Tile
• I,/ w li
X i J LwwWTirst attachment 2-t/2in S= 5/l6inx5 in. RH
#18 FH Galv. Wood f Toggle Bolt.
Ii Vi J rWff'i'j Screw. 716in.x 1 in. Galv.'
H* Wl Ww serunder
> i* is w
N . ST TL-92IS
Figure 20. “S” knobs installed on various surfaces.
(2) On stucco-finished buildings attach an “S” or “T” knob to exposed frame portion of building when practicable. To install “S” or “T” knob on stucco-finished wall, drill stucco with a 5/16-inch, short masonry drill in order to obtain a hole to accommodate a wood screw.
(3) Install “S” and “T” knobs as shown in figures 20 and 21.
Note. Do not use “T” knobs on heavy loading areas.
Stucco on Wood wood HollowTle
/Wife ■ wW ' tfi? ®Ih M •? wiMf
3l/2in#18FH ‘'' ' ' '
Galv. Wood Screw. pjAI
3 in. #18 F H Galv. Wood
_, Screw. 5/l6inx 6 in. FH,
TL-9216 Toggle Bolt.
Figure 21. “T” knobs installed on various surfaces.
j. Installing “C” Knob. (1) On masonry and brick veneer, locate the “C” knob at the center of a brick. Seam attachments should be used only to avoid cracking the brick or to obtain a more satisfactory location for the “C” knob.
(2) When installing a “C” knob on a stucco-finished wall, drill stucco with a 1/4-inch, short masonry drill to obtain a hole that will accommodate a wood screw.
(3) Install “C” knob as shown in figure 22.
Wood Stucco on wood
IQ# rft
fOW/ 2-1/2in# 10 RH Galv. 3 in. # 10 R H Galv.
I" :• I ] Wood Screw "'• ><(. Wood Screw
jOt i'll W ® ■
O T W® i\'
feSd/// f.F /A
Hollow Tile Masonry or Brick Veneer
V -I- ■> 1'l|iWOtWh2-l/2in.# 10 R H 3/l6.nx4in.BH . W°°^ ,
Toggle Bolt. ' Sc1reW '2 1014
■i mR(’■"r x 1 >n.Screw
Ancnor°r
•A- approved
eC’UiValent
TL-9217
Figure 22. “C” knobs installed on various surfaces.
20
k. Installing Drop Wire Hook. (1) Place loops of two drop wire clamps over the small end of a drop wire hook before attaching the hook on masonry. On a brick wall, drill hole for anchor in the center of a brick.
(2) On brick-veneer buildings, attach the drop wire hook to an exposed frame portion of the building when practicable. A drop wire hook may be installed on brick veneer as on masonry, (1) above, provided that the hole for the hook can be drilled at center of brick without loosening or cracking the brick.
(3) When a drop wire hook is used on wood to support unexposed drops, place loops of the drop wire clamps over the small end of the drop wire hook before attaching the drop wire hook. Place screw in a stud, if practicable.
(4) Align drop wire hook with drop wire span before attachment is complete, as shown in figure 23.
_____________J f______________________
fDrop Wire Hook
5/16 in. x 1 3/4 in.
Hammer Drive Anchor
z i
-——===|iU.l.. _..___________________-
r I j
..J __________oo____________________
I I
Drop Wire Clamps-—W-
' i B
—Z---------------TL’9218
Figure 23. Drop wire hook installed on masonry surface.
21
(5) Various installations of drop wire hooks are shown in figure 24.
WOOD
(Unexposed Wiring Only) Narrow Clapboard Wide Clapboard Shingle
f nH r Drop wire / )2in.#18R.H. ' ///»
EM \ /I Hook. A1 Galv. Wood Screw J ( I \
11 ■ I ill II III
Figure 2^. Drop wire hook installed on wood surface.
22
I. Installing House and Corner Brackets. (1) To install house or corner brackets on brick veneer, drill 1/4-inch holes in mortar between bricks in order to pass wood screws through the brick portion. Attach brackets to exposed frame portion on brick-veneer buildings when practicable.
(2) On stucco-finished buildings, attach house bracket to exposed frame portion if practicable. To install house or corner brackets on stucco-finished wall, drill stucco with 1/4-inch, short masonry drill in order to obtain holes to accommodate wood screws.
(3) Various installations of house and corner brackets are shown in figures 25 and 26.
Figure 25. House brackets installed on various surfaces.
23
Brick Veneer Stucco on Wood
S • to
ffl d-' Three 2 1/2 in. #14
V/ RHGalv.Wood
Screws.
in. #14 RH-Galv.) 'O ’’
■•'•ATiSy-Ur Wood Screws. >;«' feO-s c£l^H.Ga lv'W°od
—. . V-jMr • Screws to reach
rpii7' .; H ’ ’ ’ • '5S" wo°d sheathing.
WooD Hollow Tile
'i \ E Three 2 in. #14 RH Gale. '• L T”° W j- “• " Wood Screws. / lBi S Toggle Bolts.
WgWeL I
” ® W9220
m. Installing Angle Screws. (1) Place angle screw in stud, and screw into wall up to first bend.
(2) When mounting angle screws on stucco-finished wall, drill stucco with 5/16-inch, short masonry drill.
(3) Use a 1/4-inch auger bit to drill a lead hole in word for the 3/8-angle screw.
(4) Various installations of angle screws are shown in figure 27.
24
Masonry Stucco on Wood
r , M , 1M • Two 2 1/2 in. #14 RH Galv.
Two 1/4 in. x 1 1/4 in. v Wood Screws.
Hammer Drive Anchors
or approved equivalent.z/'J
"L •’ If necessary, use 3
In. #14 RH" Galv. Wood * l'i(1
Screws to reach wood sheathing.
Wood Hollow Tile
cy; k1 !y o y
y A .’A.< y‘UVU
XoJs^sRHGa,M^MlH Two 1/4 in. x 4 in.
Wood Screws. f. RH Togg|e
' i • y W!
Brick Veneer
. v ..-yPAi > tflllll/llf
T^s^RHGal't
yyy x i
xk' '1
X W" TL-9221
Figure 26. Comer brackets installed on various surfaces.
--- Narrow clapboard --fir j ■ '— Wide Clapboard f ir-p'—'"'I ML-_^ JIU K4-UF" _j_ -Approx. 1-1/2 in.-I . p"Approx. 1-1/2 in. ।
'/7j ''*7
3^'?’e / /I 5/161n. / / 3/8in. / /
Angle Screw. H Angle Screw. I Angle Screw. /
Shingle
. 1 hJP-^-
I, L—-Approx. 1-1/2 In. |>l-l/2 in.
5/16 in. / 3/8 in. / I
Angle Screw, i Angle Screw. / I
41LL_.„_ 411__,_J TL-9222
Figure 27. Angle screws installed on wood surfaces.
25
n. Installing Bridle Rings. (1) On masonry and bricks veneer, locate the bridle ring at the center of a brick. Seam attachments should be used only to avoid cracking the brick or to obtain a satisfactory location for the bridle ring.
(2) Install bridle rings as described in paragraph 8e(3) to (11).
16
(3) Figure 28 shows various installations of bridle rings.
Masonry wood
(Uhexposed Wiring Only)
JU till
IB
10 -14 X 1 in. f W l\
\ l Screw Anchor m I | |
■ Mibb
Bll Jill Im:*
Brick Veneer
Attach as for masonry when practicable
—10 -14 x 1 in.
Screw Anchor
feOWz TL‘9223
Figure 28. Bridle rings installed on various surfaces.
o. Installing Corner Bridle Rings. (1) Attach corner bridle rings on brick veneer, using same procedure as for masonry, provided that holes can be drilled without loosening or cracking the bricks.
(2) On stucco-finished walls, drill stucco with 1/4-inch, short masonry drill to obtain holes to accommodate wood screws.
(3) Figure 29 shows various installations of corner bridle rings.
27
Masonry Wood
(Unexposed Wiring Only) / \ 1 \ iWZfesOiH
Vi O'
Two 1/4 in. x 1 in. Hammer Drive Two 1-1/2 in. #14 RH Galv. Wood Screws.
Anchors or approved equivalent.
Stucco on wood Hollow Tile
(Unexposed Wiring Only)
IBKj liMj
Two 2 in. #14 RH Galv. Wood Screws. Two l/n'iril x 4 in. RH Toggle Bolts.
TU-9224
Figure 29. Corner bridle rings installed on various surfaces.
. /
p. Installing Insulated Screw Eyes. (1) On stucco-finished walls, drill stucco with 3/16-inch, short masonry drill.
(2) Figure 30 shows various installations of insulated screw eyes.
28
Wood Stucco on Wood
©Ijl ©rp
It I® STypa LTyp®
TL'9225
Figure 30. Insulated screw eyes installed on various surfaces.
q. Installing Drive Hooks. (1) In placing more than one drive look on one side of a pole, stagger the drive hooks at least 1/2 inch ;o avoid splitting the pole.
(2) Figure 31 shows drive hooks installed on pole.
I ’ ’ //2in-
•hi ■
I | | ' TH i n. j 11 ■ JI X
1 l-L-.ny.y.vC
11 Ww
111111 I 11
1 ' 1 1 1 1 1 TL’9226
Figure 31. Drive hooks installed on pole.
r. Installing Guardarm Hook. Figure 32 shows guardarm hook installed on guardarm.
' ' * / .• > DAM --9/16 in. x 1-3/8 in.
i > i / Washers
VNjjT.llHiiiliillM TL,9227
Figure 32. Guardarm hook installed on guardarm.
s. Installing Span Clamps. (1) Remove the wingnut, raise the threaded end of bolt, and engage suspension strand at the grooves of the span clamp. Place the hook end of the span clamp on same side of the strand as the drop wire attachments on the pole or guardarm. If initial drops cross the strand, place drop wire clamps at the wingnut end of the span clamp before re-engaging the bolt. Replace wingnut, and tighten it securely by hand.
(2) Do not attach more than two drop wires spanning from a pole or guardarm attachment, to one span clamp.
(3) A span clamp mounted on a pole not requiring a guardarm is shown in figure 33,
' > 1 > li
Note: Cable and rings
I I omitted for clarity.
WJ1
। I If a second drop is to be
) installed later in this
1 direction, same Span Clamp
* may be usecf-
111 ML
I 11:1
' >::■ | __— If a second drop is to be
' I ;8 J ’ installed later in this
‘ . i I +1'4 ,J direction, place an additional
Span Clamp y L* 9226
Figure 33. Span clamp installed on pole not requiring guardarm.
29
(4) A span clamp mounted on a pole requiring a guardarm is shown in figure 34.
Il । I 1 I
_i I I
—LJI WotK Cable and rings
f°r c'ar*Vs.
irrr>~. ?•■•
M /
Ml" I
E.''l X'Y
I |l
’J1 it; If a second drop is to be —
1 :;!; installed later in this >«•<■£’’’
. . [■:’' direction, same Span Clamp
, :;• may be used. sty?
I ill
'll | TL-9229
Figure 34- Span clamp installed on pole requiring guardarm.
t. Locating Studs in Frame Buildings. Studs in wood or stucco-on-wood buildings may usually be located by one of the following methods:
(1) Sounding.
(2) Locating studs in cellar or attic.
(3) Location of heads of nails used in fastening clapboards or trim to studding.
9. Tying Parallel Drop Wire
a. Straight Tie. The straight tie is made as shown in figure 35.
30 in. length of one strand of Twisted' F^ir Drop Wire
3 complete turns and half hitch.
T CsS? Parallel //uJSa
Drop Wire.
TL-9230
Figure 35. Straight tie (parallel drop wire).
b. Corner Tie. The corner tie is made as shown in figure 36.
3 complete turns ii and naif hitch.
© mu® mli\
Parallel 1 30 iri ,en9iri °r me sLrancl Drop Wire I Twisted Pair Drop Wire [T
TL-9231
Figure 36. Corner tie (parallel drop wire).
30
c. Dead-end Tie. The dead-end tie is made as shown in figure 37.
36 in. length of one strand of Twisted Pair Drop Wire
/# 3Completefurns'~#^W/iS*L J
ztx IS Parallel Drop Wire
KLz W ___..^--xrg^^yy^Teave 12in.for completing tie •
Irm
I 7/3 Complete turns
/Span _________________
7' 4 Complete turns
5 Complete turns. I
(ff 1
n°^ make Shar^ben^ y^T'i^
«------------—About5in. ...i.^.-- -w.—>|
2 Complete turns
around tail. Tu. 9232
Figure 37. Dead-end tie (parallel drop wire).
31
d. Dead-end Tie (Without Loop). The dead-end tie, without loop,
is made as shown in figure 38.
Span Parallel Drop Wirex 3
** 30 in. length of one strand of Twisted
Pair Droo Wire X
x-x rr-—.:.—--------------------3 complete turns-^- yA
(2) swT
& 4 complete
r , „ (turns 5 complete
(5) turns a
TL-9233
Figure 38. Dead-end tie, without loop (parallel drop wire).
10. Tying Twisted-pair Drop Wire
a. Slipover Tie. The slipover tie is made as shown in figure 39.
TL-9234
Figure 39. Slipover tie (twisted-pair drop wire).
32
33
b. Single Tie. The single tie is made as shown in figure 40.
Q Cut off excess wire^^j^^^^^
5 complete turn J
^^ZDo not cross wires Ml aft
2 8 in. length of tie wind (2) Sf
tobeofsamesizeand .// 1 VI
type as conductor wires. |R I
TL'9235
Figure !fi. Single tie (twisted-pair drop wire).
c. Double Tie. The double tie is made as shown in figure 41.
\a A '52 in-length of tie’ wire to be XJWl^F of same size and type as conductor wires
©Cut off excess wire
5 complete turns
TL’9236
Figure 41- Double tie (twisted-pair drop wire).
d. Dead-end Tie. The dead-end tie is made as shown in figure 42. ------------------------------------------------------------ —
-------About 5 in.------------)y
a32 in. length of tie wire to be of same size and type as conductor wires.
5turns~x4turns x3turns excess wire
“' Do not make sharp bend.—
TL-9237
Figure 4%- Dead-end tie (twisted-pair drop wire).
e. Dead-end Tie (Without Loop). The dead-end tie, without loop,
is made as shown in figure 43.
11. Wiring at Cable Terminals
a. General.. (1) Leave enough slack on new connections at distributing terminals so that each pair of wires will reach any terminal post. Provide the necessary slack by running the wires through the bridle rings placed below the terminal.
(2) Do not bridge more than two pairs of wires on one pair of binding posts.
(3) When more than two pairs of wire are to be bridged to the same cable pair, bridge additional wires outside the terminal and in the vertical run.
b. Wiring at “F”-type Cable Terminals. (1) When entering “F”-type cable terminals from wire runs above the “F”-type cable terminal, always run wire through the three rings below the terminal, approaching the first ring from the side of the terminal farthest from the binding posts on which the wire is to be terminated. To obtain slack for transferring wire to another cable pair or reinstalling wire, if necessary skip the bottom rings. If sufficient slack cannot be secured in this manner, make a splice in the vertical run above the terminal and route wire through the three rings.
34
____________________3 turns
32 in- ,en9th of Tie wire .Tail 136 of same size and
* type as Conductor Wires.
„ 9 turns
^Span^^*^
■ TL-9238
Figure 4$. Dead-end tie, without loop (twisted-pair drop wire).
(2) Figure 44 shows “F”-type cable terminal mounted on pole.
35
III I
I'ffl '
C Bridle Rings for F10 and I A 'I
F16 Cable Terminals. I । JL— Locate this bridle ring
A Bridle Rings for F26 \\ i^jil so that it will not interfere
Cable Terminal | Jj, i.j| with removing the cover.
I
■ < li III
Ji. JL Extend braid through i fanninS str‘P-fiSfiB i
Center these bridle rings L----—
5fe,termSg Chan"elS i -----f 3 in. for F10 and F16
e mina1, '"'M— :—-~L| 1 I L Cable Terminals.
Wfty? •1 I l^dll 1 5 in. for F26 Cable ---------------------J- Terminal.
'W—Lt
TL-9239 JJLl
Figure 44- “F”-type cable terminal mounted on pole.
(3) Figure 45 shows “F”-type cable terminal mounted on wall, with
stub cable at the top of the terminal.
36
Figure 45. “F”-type cable terminal mounted on wall, with stub cable at top of terminal.
-d i______________ffl. i_______________। u
... -----------------------------------
। —-
' 11 Cable Clamp Rings
Approx. 8 in. ----------fl W .------I----------
f I >
----------------Ji— Ik ----- JJ irHIni "
Approx. 8 in.---------~ ■ F
—■—
— - —......hH — . u
Center these bridle rings [ w H S©2© HL 11
below wiring channels _____________l it JI_________
of terminal. --------|--------------* ---------F
Approx. 3 in. for F10 and B
F16 Cable Terminals.___________J-W— —-M-l — —
Approx. 5 in. for F 25 | [“
Cable Terminal. | ’_~ |_
C Bridle Rings for F10 and ___J^n™’ % I #______________
F16 Cable Terminals. ---->----------------DA------------------r-
A Bridle Rings for F2f —I-------------i\
Cable Terminal. i 1)2 IL.
TL-9240
(4) Figure 46 shows an “F”-type cable terminal mounted on wall, with stub cable at the bottom of the terminal.
TL-9241
C Bridle Rings for F10 and F16 Cable Terminals.
A Bridle Rings for F 26 Cable Terminal.
Approx. 3 in. for F10 and F16 Cable Terminals.
Approx. 5 in. for F 26 Cable Terminal.
Center these bridle rings below wiring channels of terminal.
Approx.
s Cable Clamp Ring
JL Approx.
8 in.
Figure 46. “F”-type cable terminal mounted on wall, with stub cable at bottom of terminal.
(5) When entering from wire runs below the “F”-type cable terminal, always run wire through the three rings below the terminal, selecting as the second ring the ring farthest from the binding post on which the wire is to be terminated.
c. Wiring at “B”- and “BB”-type Cable Terminals. (1) When installing drop wire, always run the wire through two rings at the end of the fuse chamber or binding post chamber on which the wire is to be terminated. Pull the drop wire taut through the fanning strip hole, and cut it off even with the fanning strip at the opposite side of the faceplate. Push excess wire back through the fanning strip in order to obtain proper slack. Terminate the wire as directed in d below.
(2) Where two BR drop wires are to be bridged together at a “B”-type binding post chamber, extend the braid of the top wire only to the outside edge of the fanning strip.
(3) Use duct wire for cross-connecting cable pairs of outside terminals. Install cross-connecting wire as follows:
(a) Run wire through cross-connecting rings.
(b) Terminate wire on binding posts or fuses of cable pair toward subscriber, as outlined in d below.
(c) Remove excess slack, and cut wire to the length prescribed in the following directions: To terminate a cross-connecting wire on a pair of binding posts to the right of the fanning strip, cut plain conductor
37
at a point which would permit its termination on the right-hand post, but do not terminate the plain conductor on that post. Cut tracer conductor, so that it can be terminated on the right-hand post when the plain conductor is terminated on the left-hand post. To terminate a cross-connecting wire on a pair of binding posts to the left of the fanning strip, cut tracer conductor at a point which would permit its termination on the left-hand post, but do not terminate the tracer conductor on that post. Cut plain conductor so that it can be termminated on the left-hand post when the tracer conductor is terminated on the right-hand post.
(d) Terminate wire on binding posts or fuses of cable pair toward the central office. The cables and cable terminations toward the central office and toward the subscriber can be determined by inside and outside inspection of the terminal.
(4) Figure 47 shows wiring at a “B”-type cable terminal.
-j-r —— Extend braid through
------ °p __________fanning strip.
I ~~n '|h F \A
/// *| ® 0 * D iff
/1 w . ~ '■to'Nsi e/1 [////
/ // w 11111 !\\ - /'////
/// /// ® XcA **%?*•" - \ \
—r-rSV ••a , Al 9 W » \
-1 m
—V“V** ’ - ’ £ ®9 -“I n
1.9 . 1/ I
aS (ASJ — ___ 5 _ I I 9 I /H
i ® ©j „ -Lb ©
UoN _ // V i
0 _—
ZUA'--'—
TL-9242 11 *
Figure 47- Wiring at “B”-type cable terminal.
38
d. Terminating Wire at Cable Terminals. (1) Skin and clean the ends of the conductors.
(2) Loosen upper nut and washer of binding post. (If the nut and washer are corroded, replace them with new ones.)
(3) Terminate the tracer conductor on right-hand binding post or fuse, and terminate the plain conductor on left-hand binding post or fuse. . Place first conductor under lower washer and around binding post, in the direction the nut tightens. Leave a 1/8-inch separation between the insulation and the washer. (See fig. 48.)
(4) Turn the nut down in order to obtain a firm contact.
(5) Arrange conductors so that they will not be in contact with adjacent binding posts. (See fig. 48.)
Keep insulation back 1/8 in. from washers
Extend braid beyond first row of binding posts.
Insulated conductors should not be in contact with adjacent binding posts.
Twisted Pair Wire
Extend rubber insulation beyond first row of bind* ing posts
Tracer conductor at right
end braid through fanning strip.
Parallel Wire
TL-9243
Figure 48. Wires terminated on terminal strip.
39
(6) When terminating a second wire on one binding post, insert the wire between the washers. Arrange the two wires so that the unassociated tip and ring conductors are not in contact. (See fig. 49.) When the lower wire is disconnected, it is not necessary to shift the upper wire to the lower position.
^eeD insulation back / _
TL-9248
Figure 53. Parallel drop wire prepared jor bridging.
(2) Loosen the nut and washers of the Type-IA bridging connectors sufficiently to uncover the slot.
(3) Place one conductor of the main drop wire on the bottom of the slot.
(4) Insert the corresponding conductor of the second drop wire between the washer and around the binding post, in the direction that the nut tightens. Leave a Vs-inch separation between the insulation and the washer. Turn the nut down in order to obtain firm contact. (See fig. 54.)
i
—1/8 in.
Second Drop Wire
fwF ~~T।
T L* 9249 Main Dr°PWir8
Figure 5J). Type-IA bridging connector installed.
(5) Bridge the other conductor of the second drop wire to the main drop wire in a similar manner.
(6) Wrap each Type-IA bridging connector with two, reversed, halflapped layers of 3/4-inch rubber tape. Start wrapping the tape between the wires, and extend it for 1 inch on each side of the connector.
(7) Cover the entire connection with two, reversed, half-lapped layers of 3/4-inch black friction tape.
(8) If a twisted-pair wire is used, prepare the wire as shown in figure 55. Proceed as directed in (2) to (7) above.
L-----------6 in.-------—d ,, .
3/4 in. 3/4 in. J Mam Wire
<&SS"e
(Plain or Tracer) Nick insulation here' secona w re
.--------------8 tn,-----------T L- 9250
Figure 55. Twisted-pair drop wire prepared jor bridging.
12. Clearances for Aerial Plant
a. Locate wires, cables, etc., and poles or stubs so that the clearances indicated in tables V, VI, VII, and VIII will be obtained.
Table V. Horizontal clearances involving telephone poles or stubs
Between nearest part of telephone poles or stubs and Minimum horizontal clearance Remarks
Fire hydrant and signal pedestals. 3 feet Obtain 4 or more feet separation if practicable.
Nearest rail of main track. 12 feet This clearance applies both to crossings over railroads and to lines running parallel with railroads.
Nearest rail of sidings. 7 feet At loading sidings leave sufficient space for driveway.
Curb lines. 6 inches Measured to street side of curb.
Trolley feeders, electric light and power wires (0-7500 volts) which are not to be attached to telephone pole. Obtain a clearance of 3 or more feet if practicable. The minimum clearance. permitted is 1 foot plus 1 inch for each 2 feet of the distance between the telephone pole and the nearest pole of the electric line. Place telephone pole so that climbing space on it will not be reduced by the electric pole.
45
Table VI. Vertical clearance of telephone wires, cables, and guys above ground or rails
Vertical clearance* (ft.)
Remarks
Where wire, cable, or guy runs along highway: In urban districts generally. 18 Anchor guys which do not cross over driveways, roads, or pathways are not required to have any clearance above ground. The lower end of a pole-to-pole guy is required to have a clearance of at least 8 feet above ground.
In rural districts generally. 15
In rural districts only where no part of the line overhangs part of highway ordinarily traveled and where it is unlikely that loaded vehicles will cross under the line. 13
In both urban and rural districts where line is located relative to fences, ditches, embankments, etc., so that ground underneath is accessible to pedestrians only. 8
Where wire, cable, or guy crosses over: Highways. • 18 Where a guy crosses over a street or alley in urban districts, this clearance may be reduced to 16 feet at the side of the traveled way, provided the section of the guy above the street or alley is effectively insulated against the highest voltage to which it is exposed.
Street railways. See “Trolley Wire Feeder,” table VII.
Railways other than 25 feet where wire, cable, or
street railways. 27 guy parallels a trolley contact conductor.
46
Table VI. Vertical clearance oj telephone wires, cables, and guys above ground or rails—Continued
Vertical clearance* (ft.) Remarks
Driveways, urban districts. 18 More clearance should be obtained where height of farm machinery or vehicles which might pass is such as to require greater clearance.
Driveways, rural districts 15
Driveways to residence garages. 10
Walks. 8
Waterways. Clearance as specified by proper authorities.
Obstacles (excluding foreign wires, cables, and equipment). 2
* For spans of over 150 feet, increase clearance 0.1 feet for each additional 10 feet of span. This increase is equivalent to about 1 inch for each 8 feet of span.
Table VII. Vertical clearances at crossings
Between telephone wires, cables, and guys and Vertical clearances* in feet for Remarks
Telephone wires and cables Telephone guys
Electric light or power lines and cables on fixed supports. Place telephone wires or cables below electric light or power wires or cables except where authorized to place above.
Line wires. 0-300 volts to ground. 4 2 Where crossing is not within 6 feet of any pole concerned, the 4-foot clearance may be reduced to 2 feet for telephone wires or cables below supply wires.
47
Table VII. Vertical clearances at crossings—Continued
Between telephone wires, cables, and guys and Vertical clearances* in feet for Remarks
Telephone wires and cables Telephone guys
300 volts to ground to 750 between wires. 4 2 Where crossing is within 6 feet of any pole concerned, increase 4-foot clearance to 6 feet except for guys.
750-7,500 volts. 4 4
7,500-50,000 volts. 6 4
Service drops. 0-750 volts. 2 2 For wires above or below service drops and for cables below service drops.
4 2 For cables above service drops.
750-7,500 volts. 4 4 For wires or cables above or below service drops.
Supply cables. Cables having permanently grounded contin-uous metal sheath. All voltages. 4 2
Other supply cables. Same clearance as shown above for open power wires of same voltage as cable.
Trolley wires feeders. 0-750 volts. 4 2 Secure greater clearance where practicable.
750-7,500 volts. 4 4
Contact wires. 0-7,500 volts. 10 10 May be reduced to 4 feet for cables or guys protected by trolley guards, or for wires, cables, and guys located so that trolley pole cannot strike them.
48
Table VII. Vertical clearances at crossings—Continued
Between telephone wires, cables, and guys and Vertical clearances* in feet for Remarks
Telephone wires and cables Telephone guys
Foreign communication wires, cables, and guys. For public use or similarly constructed. 2 2 May be reduced by mutual consent of interested parties, provided only communication wires other than fire alarm, railway, or light and power company communication wires are concerned.
For use with electric power or trolley systems and not similar in construction to circuits for public use. 4 from wires and cables 2
2 from guys
Guys to power company poles. 2 2 Completely insulated sections of guys attached to poles carrying circuits of 7,500 volts or less may have less clearance from each other.
* For spans of over 150 feet, increase clearance 0.1 foot for each additional 10 feet of span. This increase is equivalent to about 1 inch for each 8 feet of span.
49
Table VIII. Minimum vertical clearances on jointly used poles.
Electric light, power and trolley construction
Telephone construction Trolley feeders Crossarms Bracket and span wires Nearest1 metal parts of electric light and power construction (in.)
Electric light or power (in.) Trolley (in.) Street light (in.) Trolley (in.)
Crossarms:
Center to center. — 48 48 — •—■
Bottom of crossarm. — — — 24 24 —
Line conductors. — — — — -—• 40
Suspension strand for cable:
Without guardarm. — 722 ■—- 12 12 •—
With guardarm. — Note3 — 12 12 —
Nearest part of cable. 40 — — — — —
Metal terminal. — — — 125 125 •—•
Nearest metal parts not previously mentioned (bridle rings, metal pole brackets, etc.). 40 404 — — — 40
1 Except vertical runs, lamp brackets, span wires, guys, or braces which are attached to wooden crossarms but which are more than 1 inch from transformer cases or hangars.
2 Measured to supply conductor on crossarm.
3 Where guardarm hook distribution is employed 46 inches, where knob distribution is employed 48 inches, measured to nearest metal part of supply construction, such as supply conductor carrying 750 volts or less, or metal conductor support. When measuring to supply conductor carrying over 750 volts, increase clearance from the conductor by 8 inches.
4 Measured to nearest metal part of supply construction, such as supply conductor carrying 750 volts or less, or metal conductor support. Where measuring to supply conductor carrying over 750 volts, increase clearance to 48 inches from the conductor.
5 Where a clearance of 12 inches cannot be obtained, all metal parts of terminals shall have the greatest practicable separation from lamp and trolley fixtures, including all supporting screws and bolts of both classes of attachments.
b. Illustrations of various allowable clearances are shown in figures 56, 57, and 58.
50
fBWI MAU UDLLhbt rUk wuxikW
:——-j1 [L
i '.T||
40 inches or more-^, :j 1 j j'j
'i'i?
—--gpo egL._________________________
U"—
Ijl Tr-------1 foot or more
Vertical run of drop wires-' fii
to be located 1/8 of pole 1 V iiME/Cz JI circumference away from ?> 'ALx _ y,f>
lamp bracket, if practicable, >’?
but in no case less than “IL |P|
2 inches. j(1 'h_,. ,
Uh ilr ----1 f°ot or more
fnSvjU conditions .permit
1
I H >-.40 inches or more
d V 1 .1 । |!
^****^'Ss^ inches or more separation between
Fur^^l conductors to be
***”^ v provided by the
Electric Railway
|i(H Circuits
TL-2826
Figure 56. Clearances on jointly used poles.
51
HU X
See Table below* | II XXx & •'
XLI{I ill ft,
, 11 IZin. F
M ' I Ormore A ' ’foot
X I ii M i ormore
Us I
OU-Ix-t- ---1 i___________________. I foot or more, if conditions permit
MiuHl , I foot or more if J.
'-.H' ! / conditions permit 40in. JLXi— — —■
--»| li [|| y or more • .; ■
40 in. bi;1! •! '!! !•' —*
orrtil iili J.
Q.4'ii |
HOMx4M nfr- x^
W / Clearance of x\ #
30in.or more /1 • ■ r=~~-TT—— ^X.
A I111 ii to be provided W ,• --—
yJllil; yz|l| 6feetto8feet b* electric rail-. a
awn I ‘f Practicable ^ay circuits. |
A ISxlil B _______I TL-2825
Figure 57. Clearances above trolley lines.
n £ \gjg______________
» ° . r~~r _ ~ ~T
i_^—,-------j
I t ~ Climbing Space .
I I m s
l A j--------------30l„.-------S
\ i
\ \ . M t Climbing Space .<= •
\ V Vi f s :
\ o !
\ \ 30in‘ *}
r>^ -' b ’ ‘........................c
Note: Drop wires must not obstruct the specified climbing space. -r-. o q o “?
Figure 58. Climbing space.
52
13. Drop Wire Runs from Poles
a. Runs from Poles Not Requiring Guardarms. (1) Distribute drop wire from drive hooks attached to the face or back of poles not requiring guardarms. (See fig. 59.) If brackets and knobs have been previously installed and are only partially filled, distribute drop wire from vacant grooves of the knobs. Do not attach more than two drops to a “T” knob, or more than one drop to an “S” knob.
(2) Vertical distance from suspension strand to drive hook may be varied to obtain proper clearances.
(3) Attach drop wire clamp to drive hook by passing the wire loop of the clamp over the drive hook. When the direction of the drop span is such that it will not tend to pull around to the hook end of the drive hook, place the loop of the drop wire clamp on the shank of the drive hook. Otherwise, place the loop over the hook. Place the drop wire through the hook of the drive hook only when the drop wire is run along the cable lead, or when drop wires are run to buildings on the opposite side of the street from the cable run.
(4) Pull the ring wiring on the vertical pole run tight, to avoid unsightly slack. Do not pull the ring wiring so tight, however, that strain is taken off the loop of the drop wire clamp.
Clamp
Clamp
TL-9251
Place rings so that wires will not touch cable.
fill rings to be C Bridle Rings for 16 pair or smaller terminals, A Bridle Rings for larger than 16 pair terminals.
About 6 inches more or less, preserving,however, proper joint use clearances. Drive Hook may be placed below cable if proper clearances can be obtained and there is no interference with cable stub: Obtain a minimum vertical separation of 4 inches between an existing pole step and a drive hook placed above it
Pass drop wire hrough hook of drive hook only where drop wire is run along the cable lead or where drop wires are run to buildings on opposite side of street from cable run.
ook on face or back of pole
Drive Hook
Figure 59. Typical drop wire runs from poles not requiring guardarms.
53
b. Installing Guardarms. Install guardarms as shown in figure 60.
Cable Side f
Cut I ill. :;|i gain in fl Fie
$ in. x 4 in. Carriage L I Bolt. Nut on opposite |l I side of Guard Arm.
TL-9252
f inx2iin. Sq.Washer and Nut and on opposite side of pole |-in.x2iin. Sq.Washer under head of (Length) in.Crossarm Bolt.
Figure 60. Installing guardarms.
Guard Arm Brace |in.x4iin.Drive Screw: --
Note: In placing brace proceed as follows:-
(I) Fasten brace to Guard Arm.
(2) Bend to approximately middle of face or back of pole .
(3) Fasten to pole
c. Runs from Poles Requiring Guard arms. (1) At poles requiring guardarms distribute drop wire from guardarm hooks attached to guardarm. (See fig. 61.) If brackets and knobs have been previously installed and are only partially filled, distribute drop wire from the vacant grooves of the knobs. Only two drops can be attached to a “T” knob, and only one drop to an “S” knob.
(2 ) Attach drop wire clamp to guardarm hook by passing wire loop of clamp over hook. Run. drop wire through guardarm hook.
(3 ) Pull the ring wiring in the vertical pole run tight, to avoid unsightly slack. Do not pull the ring wiring so tight, however? that strain is taken off the loop of the drop wire clamp.
54
9/16in.xl-3/Bin.Washer __
ET.W
i 11 n! 9/16 in. xf-3/Bin. Washer
Clamp —— '*»§, \
vS^yJS.^ * ^iZS. -J-d Z Clamp
Place rings so that wires y., s'*" f ‘ f| will not touch cable—I 1 8 i
,HI V^
All rings to be C Bridle Rings । • I Ifi k--
for 16 pair or smaller terminals, ji |\\]|~T ^Use this ring when
A Bridle Rings for larger than | || Jin entering left side
16 pair termirials. ! fi I of terminal.
"B
IB ■ iw
Use hooks in end holes for supporting e wires running along the lead. The preferable order for placing hooks is indicated as 1,2.
2 1
i_______< 14?
—IMP ---------------------ihftqr-1*
• “ -Top view of 11
1 2 guard arm 2 1 TL*9257
Figure 61. Typical drop wire runs jrom poles requiring guardarms.
d. Drop Wire Runs Along Lead. When it is necessary to furnish telephone service in advance of aerial cable, drop wire may be run along the lead attached to drive hooks or existing pole brackets, knobs, and crossarms. Place drop wire with proper clearances and, when practicable, at a height where it does not interfere with future placing of cable. On aerial cable lead, where terminals are not placed on every pole, it may be necessary to parallel the cable with drop wire. Various methods of paralleling the cable with drop wire follow.
(1) Where ground clearances permit, place the drop wire below the cable. Place drive hooks in the pole on the cable side about 6 inches below the strand for the run-along the lead. At distributing points, attach the drop wire to a hook placed on the face or back of the pole.
(2) When proper ground clearances cannot be obtained with the drop wire placed below the cable run, and when sufficient space is available above the cable, place drive hooks above the strand at such a height that the drop wire will not whip against the strand or cable. Maintain proper joint clearances.
55
(3) If proper clearances can be obtained, drop wire runs along the lead, where guardarms are in place, should be made on drive hooks placed in the pole beneath the cable.
(4) When it is necessary to run the drop wire from guardarm to guardarm, place guardarm hooks and dead-end the wire from both directions with drop wire clamps.
(5) Make party-line taps to drop wire runs along lead with bridging connectors. Locate a bridging point near the pole from which the drop wire to the building is distributed from a drop wire lead. Bridge should be made in the span. Locate the center of the bridging point approximately 12 inches from the point of attachment on the pole.
e. Number of Drop Spans per Drive Hook of Guardarm Hook. (1) Distribution points where no run along lead is involved, (a) Three drop spans crossing a highway may be attached to one drive hook. .
(b) Four drop spans attached to buildings on the same side of highway as the pole line may be attached to one drive hook.
(c) If the direction of the drops and the space on the drive hooks will permit, any combination of (a) and (b) above may be used.
(2) Distribution points where run along lead is involved, (a) Three drop spans along the lead may be attached to one drive hook, if no other spans are attached to the same drive hook.
(b) Two drop spans along the lead, one across the highway and one to a building on the same side of highway as the pole line, may be attached to the same drive hook.
(c) One drop span along the lead, two drop spans across the highway, and three drop spans on the same side of highway as the pole line, may be attached to the same drive hook, if the available space on the drive hook permits this number of drops.
(3) Runs along lead, (a) In straight sections of line where the drive hook is placed on the cable side of the pole, four drop wire clips can be placed on one drive hook.
(b) When there is a corner on the pole, and when the pull is away from the pole, three drop wire clips may be placed on one drive hook.
(c) When the pull on a corner pole is against the pole, four drop wire clips may be placed on one drive hook.
(d) If there is a corner on the pole and if the drop wire is attached by drop wire clamps, four clamps may be placed on one drive hook.
/. Span from Suspension Strand. (1) Span from a suspension strand only if right-of-way difficulties, tree interference, reduction of climbing space, etc., make it impracticable to run the drop directly to the station from a pole of an aerial cable lead.
(2) Note the following points in connection with the installation of spans from suspension strands:
(a) Do not attach more than two drop wires spanning from a pole or guardarm attachment to one clamp.
(b) Attach the span from the pole or guardarm to the clamp at the hook end. The span may also be attached from the building to either the hook or wingnut end.
(c) A second drop may be attached to the hook end of an existing span clamp, by passing the loop of the drop wire clamp over the hook of the span clamp without loosening the wingnut.
(3) Typical spans from suspension strands are shown in figure 62.
56
57
i 1 • iJaSl IJ/iW
| j Cable and rings omitted
I 11 for clarity.
I I nN If a second drop is in-
I I w stalled later in this
„ direction, same clamp
। maybe used
second drop sPans in
> nK opposite direction place
I XXa second clamp.
I II' i X
.Ityil
i I f ^y
■ If a second drop Is installed
I | later in the same direction Ar
•• I ' I as existing drop,same span
** clamp may be used. TL-9254
Figure 62. Typical spans from suspension strand.
Figure 64- Drop wire run from open line.
14. Drop Wire Runs on Buildings
a. Planning. When planning building runs, observe the following rules:
(1) Locate the first attachment so that the drop will have necessary-clearance above roadways and footways.
(2) Locate first attachments so that the drop will clear electric light, power, and trolley wires. (See table VII.)
(3) Separate drop wires requiring station protection from inflammable or conducting materials.
58
g. Drops from Open Wire Lines. (1) Run drops from open wire lines from a guardarm hook. Bore a %-inch hole for guardarm hook and install the hook. (See fig. 63.)
fipw
^sGuard Arm
xTo station ^\Hook
See that drop, spanning from crossarm
clears end wire existing or to TI - Q 9 R R
be placed in the future, on * •-
arm below.
Figure 63. Guardarm hook installed on guardarm.
(2) Run drop from open wire lines attached to wooden pole brackets by dead-ending the drop wire on a drive hook. (See fig. 64.)
ts5Sss.
ITf
i । itr
1
\ J&
i । w
^ihll
W1 । TL-9256
b. First Attachments on Buildings. (1) When the original installation is one drop attached to masonry or brick veneer, use a drop wire clamp to support the pole-to-building span; use another drop wire clamp to support the building run. (See fig. 65.)
" Drop Wire Hook-—
Drop Wire Clamps^^^
^Drop Wire Span x
Figure 65. Drop wire span attached to building.
(2) When a second drop is to be attached to a drop wire hook on masonry or brick veneer, remove the drop wire clamp from the building run of the first drop and place a “C” knob about 6 inches behind the first span attachment. (See fig. 66.)
___ . Approx. 6 in.—-d .. ,»
' ----- 11 H—
Drop Wire Hook ——J ■
Drop Wire Clamps ~
Drop Wire Spans '
’ TL-9259
Figure 66. Double drop wire span attached to building.
59
(3) When installing a first attachment on an unexposed run on a frame building, use a drop wire clamp to support the pole-to-building span and place a “C” knob on the run about 6 inches from the drop wire clamp. (See fig. 67.)
Drop Wire Hook----
Drop Wire Clamp---
Approx.
----- 6 'n
C Knob
Th9260
Figure 67. First attachment in unexposed area on building.
c. Installing Attachments. (1) Install all attachments as described in paragraphs 7 and 8.
(2) Use “S”-type corner bracket to pass comers and small obstructions; use “L”-type corner bracket to pass large obstructions.
(3) Mount all angle screws so that the pull of the drop wire span will not tend to turn the angle screw out of the wall.
d. Last Attachments. (1) Last attachment and entrance should be as close together as practicable, and should never be farther than 18 inches apart.
(2) Drip loops need not be provided where porcelain entrance tubes slope upward from the outside. Under other condition provide a 1%-inch drip loop.
(3) Use “C” knobs for last attachments on all inflammable and conducting materials.
(4) Bridle or drive rings may be used on conductors or materials which are not inflammable.
e. Typical Drop Wire Buns. Figures 68, 69, and 70 show typical drop wire runs on buildings.
60
J ^-Approx. 6 in.
" i I ^Insulated Screw Eye
|w||r "\I" r I al M:.
■»■ ^WreClanp- - «* eye™ —p3~t ~~^-d
" ■ r‘
S ~ 'HI zffi’ - lH L_ i Will'?-. fiiiH"- miuiiikL-, _i—i— l_lj
'“MgS~~i~ i-,
^Bridle Rin9
'if^SaZu ' ‘i —- 'J —:vwR>EsHr-?1
^5^ l_ ^-^^Tape
__y-—L-jiniafci—— —«-«.'•
' TL-9263
Figure 70. Typical drop- wire run on brick building.
15. Block Wire Runs
a. Planning. (1) Use porcelain insulation for separation between a building and a block wire run requiring station protection and attached to inflammable or conducting materials.
(2) Do not run block wire in front of signs where it will interfere with fire escapes, hoists, doors, etc.
(3) Do not place ring runs on walls against which other walls may be built.
(4) Locate ring runs for permanency and accessibility as follows:
(a) Place run on rear or side wall of buildings whenever practicable.
(b) Place run along smooth part of brick wall rather than along rough foundations.
(c) Do not attach ring run to materials, such as tin or sheet metals, which will require frequent replacement.
(d) Avoid attaching runs to old, deteriorated, or temporary frame buildings.
(e) Locate runs so that wire will be reasonably free from mechanical injury.
(/) Make run as short and with as few turns as possible.
(g) Make all runs either vertical or horizontal.
62
(7i) Avoid electric light and power lines.
(f) Locate the run so that it is subjected to as few obstructions as possible.
O’) Do not place anchors closer than 10 inches to the top or comer of a wall, except when the run extends around a corner.
(5) Follow the cable run when fastening a drop wire run on a building where the cable has already been placed.
(6) Reuse an existing block wire run whenever possible, but make a thorough check and replace any loose or worn equipment on the run before reusing it.
b. Selection of Attaching Devices. (1) Use bridle or drive rings or insulated screw eyes when placing a ring run where no cable exists.
(2) Use metal rings on all nonconducting or noninflammable substances.
(3).Use insulated screw eyes on all conducting and inflammable materials when the wiring is exposed. Metal rings may be used on all types of materials when the wiring is unexposed.
c. Installing Attachments. Install attachments as described in paragraphs 7 and 8.
. d. Placing Block Wires. .(1) On existing runs, lay wire in bridle rings or cable clamp rings; do not pull wire through the rings.
(2) In new installations wire may be drawn through the rings.
(3) Pull block wires tight, to avoid unsightly sag. Do not pull block wire so tight, however, that undue strain on the wires results.'
e. Aerial Block Wire Spans. (1) Avoid aerial spans which may open an exposure that would not otherwise exist.
(2) Where an aerial span crosses a driveway or private property, provide proper clearances. (See Table VI.)
(3) Where a span is 5 feet or less, no special support is required.
(4) Where a span is 35 feet or less, the construction shown in figure 71 may be used.
M I I ' / f >
-Ju ..■ „ l#/' I.
Clamp g
J | This construction shall not be used 'I . I > Ur
where span is over 35 feet in length i l| J "(I, js
TL-9264
Figure 71. Span construction under 35 feet in length.
63
(5) Where the span is over 35 feet long, use the construction as shown in figure 72.
it /1i /A A A. / S Wall Strap fastened
•'-^=-^-11------to wall with twoSfein.x2in.
/X’Wz Hammer Drive Anchors or
—। ~ approved e9uiva,ent
Ciamp ^-2200 Lb.. Strand
I / ) **___ 3feet ___________
V==^=n.'-------------------f Dragline-7 between rings
Span, from Corner of wall
V2 in. L Wall Straps. Fasten each strap to wall with twoV8inx 2in. Hammer Drive Anchors or «
. X aPProved eqwaient-r-~^^
Lb^Strand
TL 9263 Dragline between ringX\
Figure 72. Span construction over 35 feet in length.
j. Last Attachments. (1) Last attachment and entrance should be as close together as possible, and not more than 18 inches apart.
(2) Where practicable, place the last attachment below the entrance hole.
g. Party-line Taps. (1) Bridge the party line at the terminal if the most convenient spot for attaching the drop to the lead is at the pole or within the terminal. The party line can be bridged at the terminal if two wires are not already on the binding posts of the terminal.
F“\ lhe bridge may be made directly to the wire with a type-1 A bridging connector and a span clamp, if the most convenient spot is more than 50 feet from terminal.
h. Typical Block Wire Runs. Figures 73 and 74 show typical block wire runs on buildings.
64
Figure 73, Typical block wire run on brick building
65
TL-9266
■: isssjy . '
: I By wl^iag d $• «y =rzh F —q E^llIk
' O —uzHn EEhF i ^F f s - ------------o few ~~ a p ' — i [Ji Li ~
J »&x Ik*’" li __| fewi If_ y?—jtea R —
n p ’i f i £_____ofeSsZqte^1 i~~W |m~
iiBBpllil in tegfl:
^S| r
'• '—^-^TL-9267
Figure 74- Typical block wire run on frame building.
66
SECTION III
STATION PROTECTION
16. Station Protectors
a. Use. (1) Telephone lines (except underground systems) are subject to electrical hazards from two sources: electric light and power lines, and lightning.
(2) The primary means of protecting telephone lines against electric light and power lines is planning aerial construction to prevent contact between the two kinds of lines. The best methods of aerial construction, however, cannot be relied upon to prevent all accidental contacts. Station protectors are the only practicable means of protecting the station apparatus against lightning and possible contact with electric light and power lines, and are required wherever such accidental contacts are possible.
b. Stations Requiring Protection. All telephone stations served by conductors need protection, if the stations are subject to disturbance from lightning or to direct or indirect contact with a foreign circuit operating at more, than 250 volts. Such stations are called “exposed stations” and the lines serving them, “exposed lines.”
c. Locating Protectors Inside. (1) The location of protectors inside of buildings is dependent on the following considerations:
(a) Available points of entrance for line wires.
(b) Location of approved protector ground.
(c) Location of the telephone.
(d) Available mounting surfaces for the protector.
(2) Place the protector where it is accessible for inspection and maintenance, and where those making the inspection or repairs will not be exposed to contact with power wires, moving machinery, etc.
(3) Do not mount the protector near inflammable materials or in a room where dust or gas of combustible materials is in the atmosphere. Mount the protector in a dry well-ventilated location.
. (4) Mount the protector at least 1 foot from electric light or power wires, meters and accessories, and gas and water meters (unless the protector is mounted in the same protector cabinet as the other services).
d. Locating Protectors Outside. If a suitable location for the protector cannot be found inside the building, place the protector on the outside of the building in a place well sheltered from rain, sleet, and snow.
e. Mounting Protectors Inside. (1) Protectors may be mounted on any substantial surface. If a substantial surface is not available or if the surfaces available are rough or damp, mount protector on a suitable wood backboard.
(2) Do not mount protectors horizontally, with fuses one above the other.
(3) Protectors may be mounted on ceilings.
(4) When protectors are installed side by side, mount them so that their centers are at least 5 inches apart. (See fig. 75 (F).)
67
(5) On backboards or solid wood surfaces, use l^-inch No. 8 round head, blued, wood screws; on wood lath and plaster, use 2-inch No. 8 round head, blued wood screws. (See fig. 75 (D).)
/. Wiring Protectors. (1) A porcelain tube should extend % inch beyond the wall. In locations where appearance is not important, the tube need not be cut unless there is a possibility of breaking the exposed portion. (See fig. 75 (A).)
(2) The braid on wires should be allowed to extend % inch beyond the “C” knob. . (See fig. 75 (B).)
(3) Mount “C” knobs 1 to 4 inches from the top of the protector. The 4-inch distance is most practicable, for if the line wires are broken, the knob can be moved closer to the protector, in order to obtain slack. (See fig. 75 (C).)
(4) Terminate the line and inside tracer wires to the right-hand side of the protector. (See fig. 75 (E).)
(5) The last fastener placed on inside wires at the protector will be an inside wiring cleat. This fastener must be within 2 inches of the protector. (See fig. 75 (G).)
(6) Strip the insulation back % inch at all terminals. Wire should circle the terminal for a three-quarter turn, and should extend slightly beyond the edge of the washer. Place wire around the terminal in a clockwise direction. (See fig. 75 (H).)
(7) No fasteners are needed on a ground wire strap between protectors. (See fig. 75 (I).)
(8) In making corner turns, place inside wiring nails about 1 inch apart. (See fig. 75 (J).)
(9) When protectors are not mounted on a backboard, place line terminals in line with each other, if practicable. (See fig. 75 (K).)
(10) Slots in fuses are faced toward the protector. (See fig. 75 (L).)
(11) In multiple wire runs, stagger fasteners % inch. (See fie; 75 (M).)
(12) Slotted portion of washers on the Cook Type B-7 protector are open toward the wire, permitting the wire to pass through the slot (See fig. 75 (N).)
(13) Place ground wire behind the pronged washer on W. E. 98-A protectors. (See fig. 75 (0).)
(14) Make equal in length the line wires which go to protectors. (See fig. 75 (P).)
g. Mounting Protectors Outside. (1) When it is not practicable or permissible to place a protector inside a building, or when maintenance conditions make an outdoor mounting advisable, the protector can be mounted outside on a proper protector mounting.
(2) Many types of protectors and mountings are available for outdoor use, the most common protector being the Cook Type 0.
(3) The Cook Type 0 protector is mounted as shown in figure 76 and is wired as shown in figure 77.
17. Protector Grounds
a. Public Water System. (1) Grounds on a public water system are preferred to any other type of ground.
(2) Make connections only to cold-water pipes which are in service.
68
69
Lai
j/Fk—F——|Zi
\ Z ~’ A J)
i -pJ^^L,-.’f\ I towj
C^n^t / " / pZ
§ *—W @ ©JU Z AZJ
i * jiy> - t
y -- |g^‘“
coox #-? w.£ vq-a
Figure 75. Wiring at Cook Type B-7 and W.E. Type 98-A protectors.
STEP NO. I STEP NO. 2 STEP NO.3
(T%) JI IIIBhiOL flKMS
lF>t H 'i'
U111 II ji | 1
® ii
*_ l^sLJr
TL-3451
Figure 76. Mounting procedure for Cook Type 0 protector.
SIDE VIEW
BOTTOM VIEW
OF PROTECTOR fuses
r, CLEARNESS IF A SIGNALING GROUND
^ZZ Z3-DR0PWIRE DO/z 1 ZoM wire is used, place
( ^17^5/ E / 7/, I IT BETWEEN 2ND NUT
Atir'l Pl pltijM AND WASHER.
.lIPLlIlJl |V - BRIDLE wire J ihTik J||L /
lo iO
M'ffink KK/J isx”
Z . < z/ .~7FW ^gj§y*g_ISTNUT AND
NOTCHED WASHER.
lSd^re ^w^>oreaxt
THROUGH HOLE & 8^8 IO EXTEND
nearest wall drop wire'*' THR
A ■ .■ T_•_” ■ S __
TL-9291
Figure 79. Ground wire clamp installed on a vertical run.
71
1 HBM'
h. Installing Ground Rods. (1) Locate a ground rod where it will be least open to breakage or tampering. Avoid placing a ground rod in public alleys, or on the street or sidewalk side of a building.
(2) Inspect the ground rod before and after installation, to make sure that the tail wire is not broken. If the tail wire is broken, use another ground rod.
(3) To minimize electrolysis and the effect of air pockets, place ground rods at least 12 inches apart. Place ground rods about 24 inches away from wood poles and about 12 inches away from other structures (except in locations inside a building).
(4) Keep the ground wire at least 6 feet away from the ground rods of other services.
(5) Make a splice between the ground wire and the ground rod tail wire just above the ground, unless a splice located just above the ground would be next to conducting or combustible material. If the splice is near combustible or conducting material, bury the splice.
(6) The basement of a building is the most suitable location for a ground rod. Drive the ground rod as close as possible to the masonry wall.
i. Fastening Ground Wire. (1) Fasten ground wires as shown in figure 80. Locate the run where it will not be broken or detached. For ordinary runs, place fasteners 24 inches apart. On wire which is within 5 feet of the floor (or otherwise placed so that it is liable to displacement) , place fasteners 16 inches apart. When spanning wire on beams in cellars or basements, place fasteners on every beam. When a run is made on beams, and parallel to a wall, run the wire within 3 inches of the wall; place a fastener on each beam.
(2 ) When running ground wire, observe the following rules:
(a) Run the wire as directly as practicable from protector to ground clamp. Do not make spirals or bends greater than a right angle.
. (b) Except for splice to ground rod or No. 6 ground wire, and strapping between protectors, the ground wire must be in one piece.
(c) On open runs the protector ground wire and the instrument, or inside, wires must be placed under separately mounted fasteners. However, the protector ground wire and the instrument, or inside, wires may be in contact with each other at times and may pass through the same holes, conduits, etc. Do not twist inside wires and ground wire together.
(d) Do not place protector ground wires in ring runs.
Electric Bell or
Open Light Signaling Wires Pipes, Electric Light
*V|RING Conduit. Armored
Electric Cable
Where a ground rod is used as a protector erm mo me riparanrp shall be at least 3 inches
TL9275
Figure 80. Minimum clearances between ground wires and electric light, power, or signaling wires.
72
SECTION IV
INSIDE INSTALLATION
18. Building Entrances
a. General. (1) The selection of a point of entrance is dependent on the locations of the telephone, the protector or connecting block, and the exterior and interior wire runs. Before selecting a point of entrance, survey the building premises for the location of the above-mentioned apparatus.
(2) A point of entrance for a masonry or stucco-on-masonry building can be a window or door frame (except a metal door frame). On a, frame or stucco-on-frame building, a point of entrance can be established immediately above or through the foundation sill. Make the entrance hole through the foundation sill so that the hole clears joists or studs. (See fig. 81.)
b. Wood Window Frames. (1) Place entrance holes in wood window frames so that the holes do not interfere with the opening or closing of (he windows.
(2) When the side of the window frame at the top is selected as the site of the hole, bore the hole as close as possible to the top of the window frame, to avoid interfering with the cord pulleys.
(3) When the side of the window frame at the bottom is selected as
73
Without Firestop
Z~Eotrance7ioie~~^ //
'—7—) i l '^L r -•— stud
Joist
pl... irp
Outside Section A-A Inside
With Firestop
------- 1 /1 / BpFirestoo A
■—E ntra nceHofT~ T 3\ L
—PPfP I[~_Firest°pB
yxj
i r-— if—i
Outside Section B-B inside
TL-9268
Figure SI. Entrance holes in foundation sill.
74
the site of the hole, bore the hole within 3 inches of the sill, to avoid entering the sash-weight pocket.
(4) Figure 82 shows typical entrances through wood window frames.
Brick Buildings - Upper floors
I'l-rtZ-' ‘Ff'VvTV
-Ji vU
^2=== = || Section A-A
El J
Above L—j
111—Pulley-----------------------4:1'-'-'-W' |
, ; rW™® II
jCJ—p I II Section B-B
miii . n mj
===^=J— l.r Not more pz=2...z 11
pJ=31, I" 4—==_» than 3 in.---~t~i
IW--4-_ ' ---llWOw S’
~-2l [_[ .....L ■ —j
Section C C
Frame Buildings - Upper Floors
1I ffiL™.
Basement (Brick Shown) Section D D
QpZl
□ L TzfiiShable-' j I N*
•ynTTl Entrance
J " • 11 ' —» Section A-A
• Indicates Desirable Entrance Points TL9269
Figure 82. Entrance holes through wood window frames.
(5) Where metal shutters or fire screens are placed over a window, cut a slot in the seam between the bricks or tiles at the edge of the shutter or screen. Run the wire along the slot between the tiles or bricks to a desirable point of entrance. (See fig. 83.)
_ 0 o k^EE^-dr"'^^
I 0 e-J 55
0 = <’ Cut Slot m
□U • ===== jU in brick jfiZXJd H
1 i::
|£tL 1 L
i Jir g iw
i - 53 k
i H 55 E H
i: . :fl:| ^3 E
TL9270 • Indicates Desirable Entrance Points
Figure 83. Entrance holes through windows with metal fire screens and shutters.
c. Metal Window Frames. (1) If the metal window frame is set in masonry, drill the entrance hole halfway from the outside and halfway from the inside of the window frame. In drilling from the outside and the inside, slant the hole away from the window frame in each case so that the two drilled holes meet at an angle. (See fig. 84.)
-Meta! Frame
Entrance Hole
TL927I
Drill in hack of metal frame so as to clear metal.
Section AA
Figure 84. Entrance holes through metal window frames set in masonry.
75
\ n
Entrance Hole
(2) If the metal window frame is set in wood, make the entrance hole as shown in figure 85.
d. Wood Door Frames. Entrance holes in wood door frames are drilled in the same manner as those in wood window frames. (See par. 18b (1) through (4).)
e. Metal Door Frames. Do not drill entrance holes through metal door frames.
/• Size of Entrance Holes. (1) The diameter of an entrance hole should not be greater than one-half the width of the material through which the hole is made. If necessary, drill several holes of small diameter rather than a single large hole.
(2) hen a hole is drilled in a window frame below the sash-cord pulley, the diameter of the hole must not exceed % inch.
g. Making Entrance Holes. Wherever practicable, slant entrance holes upward from the outside. When drilling an entrance hole i a brick wall, make the hole in a seam between bricks. Start drilling the hole on the side of the wall on which a neat appearance is desirable.
h. Porcelain Tubes in Entrance Holes. (1) Porcelain tubes are lequired m entrance holes of the size and capacity indicated in table IX.
76
1 ft___I Bl
*.XfSSSM- Side of metal frame ic ft ssrl
generally constructed l/fl ■
* finf3! the $ame as the to°- '
| If ! snown in section A-A. yjl ■
3IIUI- Mi
Section A-A
i in u
flEff
• Indicates Desirable Entrance Points Section B-B
TL9272
Figure 85. Entrance holes through metal window frames set in wood.
Table IX. Entrance holes requiring porcelain tubes
Wire 24-in. tube 24-in. hole No. of wires 24-in. tube 1 J4-in. hole 1-in. tube 124-in. hole
Bridle wire or Wire W-69-A. 2 7 13
BP or TP drop wire, Wire W-108, or Wire W-108-A. 2 6 11
BR or TR drop wire. 1 4 7
Wire W-50y 1 2 4
(2) Porcelain tubes are not required in entrance holes of the size and capacity indicated in table X.
Table X. Entrance holes not requiring porcelain tubes
Wire No. of wires
24-in. hole 24-in. hole 24-in. hole 1-in. hole
Bridle wire or Wire W-69-A. 2 3 7 13
BP or TP drop wire, Wire W-108, or Wire W-108-A. 2 3 6 11
BR or TR drop wire. 1 2 4 7
Wire W-50. 1 1 2 4
(3) When porcelain tubes are required, place them as shown in figure 86.
Not less than
Outside
Slope tube upward from outside. Head of tube should be outside where practicable.
Tube must be securely held in place, if necessary use tape.
in one piece. . .. riction Tape (Number of ns ae layers as required to make
TL-9273
snug fit.)
Figure 86. Porcelain tube in place.
tj
19. Selection of Wire
a. Bell System GN Station Wire or Wire W-117. Use Bell System GN station wire or Wire W-117 for all interior station wiring, except in ducts, wet conduits, or other locations where severe moisture conditions are present. Use brown Bell System GN station wire on dark surfaces and ivory Bell System GN station wire on light surfaces.
b. Bridle Wire. (1) Use bridle wire when a stronger wire than Bell System GN station wire or Wire W-117 is required. Use bridle wire in factories and warehouses where the wire may be subject to physical damage or where the standard spacing of fasteners for interior wiring must be exceeded. Use bridle wire under buildings that do not have basements, and for all station wiring extended outside a building, such as wiring to an outdoor telephone set, to a loud-ringing bell, or from an outside protector mounting to a telephone inside the building.
(2) If appearance is not important, run bridle wire or drop wire directly to the telephone location. If appearance is important, make the exposed length of wire as short as possible and tape the exposed wire with ivory or brown friction tape.
c. Cross-connecting. Use Bell System GN station wire in inside cross-connecting boxes, frames, and terminals where severe moisture is not present.
d. Splicing. (1) Do not splice inside house wire at new installations where the run is 50 feet or less.
(2) Wire at reinstallations may be spliced under the following circumstances:
(a) Where the old run is 20 feet or more in length and in good condition.
(b) Where removal of the old run would leave an unsightly appearance.
(c) Where the old run is less than 20 feet in length but more labor would be involved to replace it than to make a splice.
20. Minimum Clearances and Protection
a. Clearances. (1) Maintain clearances of at least 6 inches between telephone wiring and foreign ground wires.
(2) When it is convenient to run wire outside the building from the station side of the protector (in cases where the main station requires a protector)or when it is convenient to run wire outside the building to an extension station or extension ringer, interior wiring extending outside the building must be separated from the line wire by at least 2 inches and from electric service wires by at least 6 inches. Where proper clearances cannot be obtained, protect the wire as shown in figure 87.
(3) Other minimum clearances are shown in figure 80. If the proper clearances cannot be obtained, protect wire crossing or paralleling pipes or foreign wires as shown in figure 87.
(4) Do not place wire in a pipe, conduit, or compartment containing electric light or power wires. Unless the telephone wire is separated from the electric light and power wires by a suitable partition, do not place wire in the same outlet box, junction box, or similar fitting or compartment, with electric light and power wires. If the power wires are introduced into an outlet box, junction box, or compartment solely for power supply to signaling equipment, or for connection to
78
remote control equipment, telephone wire need not be separated from power wires by a partition.
(5) It is permissible to place telephone wire in same conduit or runway with signaling wire provided that the voltage for operating the signals does not exceed 48.
b. Protection. (1) Run wire from the telephone, protector, connecting block, or cable terminal so that the wire is not exposed to injury, and so that the run is as short as is consistent with neat appearance.
(2) Protect wire with two layers of friction tape, half-lapped and reversed, where wire is run in back of fire shutter or fire screen, across metal beams, through gratings, over any metal obstruction (such as a cable), or over sharp corners.
(3) Protect wires passing through floors and walls as shown in figure 88.
(4) Where wire (except ground wire) passes through the floor near wall or baseboard and may be exposed to mechanical injury, protect the wire with a pipe or conduit. (See fig. 89.)
79
Securing the Woven Conduit
'''"-Tape-""^ ''-"S” Wire Clip''' Ground Wire Clamp^
Crossing Exposed Steam Pipes
FBrcelain 11,136
or s Wire Clip
Where within in. use porcelain tube.
Crossing Open Electric Light Wires
At least 2 in.
X. / y«yir'As c’ose t|lhe
y..XyyS as pra,-tica|'’,p
Where crossing within 2 in., use a % in. porcelain tube projecting at least 2 in. beyond the electric light wires.
II J --------------At least 2 in.-------------
Where within % in. apply woven conduit to ground wire or 1 layer of rubber tape and
1 layer of friction tape.
Note: Water pipes are liable to sweat under certain conditions. Where practicable therefore, water pipes should be crossed above rather than below.
TL-9274
Figure 87. Protecting a wire crossing metallic object.
(5) Where interior wiring passes through the floor away from wall or baseboard, protect the wiring from mechanical injury with a floor outlet or standpipe.
(6) Taping or other protection is not necessary when wire parallels or crosses other telephone wires, electric light wires in wood moulding, or covered steam pipes. Protection is not necessary if wiring passes y2’ inch or more above water pipes.
80
Woodwork Floors Metal sheathing. Plaster
• or Cement on Metal Lath
I ,, .
. a lii! \ % in. Hole
At least i / fey % I /
in. Unbushed 4 in. I
i 2 layers of Friction Tape
iwjgwte where passing through the
, . . . i =£=£.-v-^ partition.
% lit Hole -^ly feu'.: 45^44
Hollow Tile,
Plaster on Plaster Block
Wood Lath or other
lin / Abrasive’Material
% in. Hole i c2Layersof [L n
Friction Tape n>ij | >|/ .*>>•.’ M fefefi
' • Where it is evident % in. Hole
2 Layers of that floor is mopped,
I-action |• -gjve j |ayer Of rubbgj. : /
aPe tape and 1 layer of 2 Layers of tyAfelfe
friction tape. Friction
TL-9276 TaPe f “ W
Figure 88. Protecting wires passing through woodwork, floors, and walls.
Plaster on Hollow Tile Masonry
^^^Extendpipeor conduit on base-। board or wall as
fefe II high as is necessarfefeqr^ I
I ■■■WferJy for protection.——|=rX"'sS^
in- x 4 in Button 1fefefefe
(Size) /7 A Head Toggle Bolt.
Cable Strap I W JI 'n- No. 14 R.H.
1 (Size) Cable Strap/ , 'uFjyFC Galvanized Wood
1 lf^ I Screws in 10-14
i X1
- Splicing Closet 5 ft. to 6 ft. •( /
s/__l______________________ | /Tie Conduit /
M |^^sfrioutin^Zrmin;dCabine^^Tft©l©l"^al^lbow<^©[/^
TL-9279
Figure 91. Fiber duct system under floor.
d. Conduit Running Under Floor from Distributing Terminal Cabinet. This system of distribution consists of a network of iron tonduits extending from distributing terminal cabinet or supply closet, Trough the floors to outlets in the walls or columns of the building, >r to outlets in the floor. (See fig. 92.)
Legend: |
» r m Telephone E
'i i | Outlet Box |
4«___________Si© H©, 4'V.in.x4W©__________
i I | I Distributing H |
e 1 Terminal I 'i
.1; \ Cabinet
w I. j —Conduit f I
jSs__________>qk__ A ,_________________-I.....' ~t!
TL-9280
Figure 92. Conduit and ducts running under floor from distributing terminal cabinet.
e. Metal Base Raceway. A metal base raceway takes the place of the usual baseboard. The front part of the raceway is removable, exposing two compartments: the upper one for branch electric light wires and the lower one for telephone wires. (See fig. 93.) The metal base raceway is used principally in small floor areas where it is probable that desks will be placed against the wall.
I i1 ■ ■ '■ &
■■ n
■- ('■■■’■
L'8ht Wire's V
Removable [■?’.
Face Plate * V'"'i
Bronze Mop / );>'
Molding—wtC I -•■■
Bushed Outlet' ’ •" ("A
for Telephone Wire^x^Wx'y ' ’ * •
TL*928I N For Telephone Wires
Figure 93. Metal base raceway.
f. Wood Base Raceway. This system of distribution consists of wood baseboards with space behind for telephone wires. The conduit from the floor terminal terminates in an outlet box behind the baseboard. (See fig. 94.) A brass plate covers the opening in the outlet box.
Wire ' -
Slot
.ij-'gW /Brass p|a,e for box
•M ’U‘WwmSMTO / x not shown.
Conduit to Splicing Closet
Outlet Box ' ' TL-9282
Figure 94- Wood base raceway.
83
g. Moulding Raceway. Moulding raceways are of various types. (See fig. 95.) Picture moulding is obtainable for use in small rooms; large metal or wood moulding is designed for use in assembly halls, etc. The conduit is placed through the walls between rooms or assembly halls and connects the moulding to distributing terminals.
TL9283
Figure 95. Typical moulding raceways.
23. Connecting Blocks
a. General. (1) No. 42 type connecting block has four terminals and is equipped with either an ivory or a brown cover.
(2) No. 44 type connecting block is a new 10-terminal block for terminating cords with more than four conductors. By using No. 44-A type connecting block, one, two, or three connecting blocks can be mounted under a single cover to provide 10, 20, or 30 terminals. No. 101 type covers, in ivory or brown, are provided separately for use with No. 44-A connecting blocks.
b. Locating Connecting Blocks. (1) To make connections between wires, cords, etc., use No. 42 or No. 44 type connecting blocks on desks, tables, baseboards, beams, window or door frames, or other permanent woodwork in rooms, cellars, or basements. If necessary, connecting blocks may be located on wall surfaces. A backboard must be installed, however, if the wall is damp, uneven, or does not present a surface suitable for mounting a connecting block.
(2) Many desks are constructed so that one or more connecting blocks can be mounted inside the desk pedestals. In such desks the telephone mounting cord can be brought out through a slot or hole in or near the desk top and within a few inches of the front of the desk. If special facilities for mounting connecting blocks inside a desk are not provided, mount the connecting block on the side of the desk near the top and within 6 or 8 inches of the front. If more than one No,
84
44-A type connecting block is required on a desk, mount the blocks on a backboard and mount the backboard on the desk, to avoid placing more than two holes in the desk.
(3) Do not place connecting blocks where installers or repairmen would be liable to injury in making tests or inspections at the connecting blocks. Place the blocks and associated wiring so that the equipment is not exposed to sources of damage.
c. Installing Connecting Blocks. (1) In unexposed areas (not requiring a protector), line wires may be terminated on connecting blocks located near the point of entrance to a building.
(2 ) Wherever space permits, station wires should be wound once around the connecting block, a procedure which takes strain off wires at connecting block terminals and provides slack for reterminating a station wire in case the bare end breaks off. If necessary, install inside bl^k^ on station wires to take strain off wires at the connecting
(3 ) The following fasteners are recommended for No. 42 and No. 44 type connecting blocks:
Surface Fasteners
Hardwood or backboard %-inch No. 8 round head, blued, wood screws
All other wood 1-inch No. 8 round head, blued, wood screws
Lath and plaster 2-inch No. 8 round head, blued, wood screws
Metal %-inch No. 8 round head, selftapping screws
24. Locating and Mounting Telephone Sets
a. General. (1) In locating a telephone set, the installer should be guided primarily by the wishes of the subscriber. The installer should try, however, to find a location that meets the following requirements:
(a) The telephone set should be located where the bell will be clearly heard by the subscriber.
(b) The telephone set should be installed in a dry location. The set should not be placed over or near a grounded metallic object, such as a radiator or sink, or near any electrical appliance. If it is impossible to obtain adequate separation from metallic objects or electrical appliances shorten the desk set or handset cord so that the subscriber cannot touch the metallic object or electrical appliance when he is using the telephone.
(c) Dial sets should be placed where there is sufficient light at all times.
(d) The telephsne set should be located where it is accessible for inspection and repair, and where the inspector or repairman is not subject to injury from machinery, power wires, etc.
(e) The telephone set should not be placed where it is subject to excessive vibration.
(2) Types of sets to be used in various installations are indicated in table XII.
b. Use of Backboards. (1) Use backboards when wall sets or bell boxes are to be mounted on masonry walls, solid metal walls, metal
85
lathed walls, or metal sheath walls. Use backboards on rough, uneven, or damp mounting surfaces.
(2) Use wood backboards when mounting wall sets or bell boxes with bakelite cases on metal desks or cabinets. Use wood backboards, also, when mounting wall sets or bell boxes with metal cases on masonry walls, solid metal walls, metal lathed walls, or metal sheath walls. Do not use wood backboards to mount equipment on wooden baseboards if the wall is not metal sheathed.
(3) Use metal backboards when mounting wall sets or bell boxes on surfaces other than those mentioned in (2) above.
c. Mounting backboards. (1) Fasten backboards securely to mounting surface.
(2) Use two fasteners to mount backboards on hardwood, solid metal (except metal baseboards), plaster on hollow tile, corrugated metal, and metal desks. Use three fasteners to mount backboard on sides of panel desks under table and in the knee-wells of desks. On all other surfaces mount backboards with four fasteners.
(3) Methods of fastening backboards to various surfaces are shown in figures 96 and 97.
Metal Sheath on Solid Wood
Ik in. No. 8 R.H. Biued Wood Screws
Metal Sheath on Brick
b Ik in. No. 8 i't R.H. Blued $ Wood Screws g 6-8 in. ft Screw Anchor
Metal Sheath over Furring on brick
Ik in. No. 8 R.H. Blued Wood Screws. Bore 4 holes in backboard so that screws will enter furring.
Metal Sheath over Furring on Brick with Plaster between
Ik in. No. 8 R.H. Blued
XF » 'iXWWft Wood Screws.
X&r ... • KMykWj Bore 4 holes in backboard so that screws will enter furring.
Metal Sheath over % in. Solid Wood
on Plaster on Lath
Metal Sheath over k in. Furring
ON LATH WITH PLASTER BETWEEN
Ik in. No. 8 R.H. Blued Wood Screws
2 in. No. 8 R.H. Blued Wood Screws
Metal Sheath over h in. Furring on Plaster on Lath
2 in. No. 8 R.H. Blued Wood Screws
Metal Sheath over Plaster on Lath
2 in. No. 8 R.H. Blued Wood Screws
TL-9300
Figure 96. Backboards fastened to various surfaces.
86
Table XII. Types of sets for various installations
Subscriber set ---------------------------------------------------------Hand telephone set, .--------------------------------------------------------manual Desk
Type of service Wall set Bell box stand,
------------------------------------------------------------manual
Extension Extension Extension Desk Hanging
Main Extension Main with without ringer type type ringer ringer
Sidetone:
Individual lines or regular W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. switchboard stations. 1553A 1553A 584-A-3 584-A-3 584-C-3 584DF-3 102A-3 211A-3 51 AL
Antisidetone:
Individual lines or regular Kellog Kellog W. E. W. E. W. E. W. E. W. E. W. E. W. E. switchboard stations. 9917 9917 684A-3 684A-3 684C-3 584DF-3 302AW-3 211A-3 151AL
Two or more telephones connected to the same subscriber - ----- ------ ------- ------- ------- W. E. W. E. W. E.
set- 215A-3 211A-3 151R
Local-battery-talking, common
battery-signaling (sidetone): Individual lines or regular W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. switchboard stations. 1553Y 1553Y 534Y 534Y 534Y 584DF-3 102A-3 211A-3 51AL
Local-battery-talking, common
battery - signaling (antiside-
tone) :
Individual lines or regular W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. W. E. switchboard. 653YD 653YD 634YD 634YD 634YD 584DF-3 302AW-3 211E-3 51AL
-___________________________________________________________________________________________
87
Plaster on Metal Lath
Plaster on Metal Lath on Metal Framework in. x 4 in.
B.H. Toggles
Glazed Tiling over Plaster on Metal Lath
Solid Metal
5g in. x 4 in.
B.H. Toggles
Use (2) 1 in. No. 10-24 F.H. Bright Machine Screws. Place screws diagonally opposite each other
Plaster on Plaster Board
Corrugated Metal
Jg in. x 4 in.
B.H. Toggles
Use (2) 1 in. No. 8 Parker • Kalon Self Tapping Screws. Place screws diagonally opposite each other.
Plaster on Masonry
2Jg in. No. 8 R.H. Blued Wood Screws io
6 ■ 8 x Ug in.
Screw Anchors
PLASTER ON
Hollow Tile
h in. x 4 in.
B.H. Toggles (Two required)
Plaster on
Plaster Block or Concrete Block
2Jg in. No. 8 R.H. Blued Wood Screws in 6 • 8 x Bg in. Screw Anchors.
Vi in. No. 8 R.H. Blued Wood Screws in 6 • 8 x % in.
Screw Anchors
25g hi. No. 8 R.H. Blued Wood Screws in 6 • 8 x Ug in. Screw Anchors
Ug in. No. 8 R.H. Blued Wood Screws in
6 • 8 x % in.
Screw Anchors
TU‘9299
Fig ure 97. Backboards fastened to various surfaces.
d. Locating and Mounting Wall Sets. Except in special cases mount wall sets with the center of the transmitter 56^2 inches from the floor. Mount wall sets on appropriate backboards, b and c above, h asten a wall set to a wood backboard with three 1-inch No. 10 round head, blued, wood screws; fasten a wall set to a metal backboard with three 12-24 x 9/16-inch round head, iron, machine screws.
88
89
%
e. Locating and Mounting Hanging Type Desk Sets. Locate hanging type desk sets in accordance with paragraph 24a. Mount a hanging type desk set as shown in figure 98.
Receiver of Hand Set should clear .X A^ A
( '-----desk overhang.----■, A /A.
. I -------A^ //I
Inside Wirez AFA '■ AZzz:—z'Mxx TrtZZ \
C Type Hand Set ■’. /-Li 2,
Mounting----► M ’> '
~4 ^3%- J . /
Fasten to wooden desks \ // A . j
with 1 inch No. 8 R. H. f / /< <
Blued Wood Screws. 1 f AS/ A AA
WAA :: '> f :-w A A A 1
Fasten to metal desks r ; A /A
with % inch No. 8 Self A Ar i : / /A^ I
Tapping Screws. Drill I 1
holes with No. 30 Drill. | [if
I o,'
TL-9298 •
Figure 98. Hanging type desk set mounted on desk.
f. Locating and Mounting Bell Boxes for Desk Sets. (1) When the telephone set is to be placed on a desk or table, locate the bell box on the wall at a point where the box will be least liable to damage.
(2) If the distance between the desk or table and the wall exceeds 8 inches, mount the bell box directly on the desk or table.
(3) Locate bell boxes on desks as shown in figure 99. Location 1 (fig. 99) is preferable for bell boxes with bakelite covers; location 2 (fig. 99) is preferable for bell boxes with metal covers.
Wood Desks Metal desks
ySM^^ccition i
LllLocati°n i iF I
ifeld FCJU>ocation 2 '^1 Lcati^2H>.acket [or m2unt'
r—2 cM' uuvauu,,t I mg subscriber
MyJy j AS ' Z/i sets ^urn'shed by
AA i AA\ \ some d8sk manu-
' Ax I // Lt facturers as part
// wdesk.
U TL‘9294
Figure 99. Bell boxes mounted on desk.
(4) Place bell boxes on the left when mounting bell boxes underneath tables.
(5) If the bell box is mounted so that the bells are above one another,
ringing efficiency is decreased. Whenever possible, mount the bell box so that the gongs are down.
(6) Fasten the bell box on the backboard and mount the backboard, c above.
25. Fastening tand Terminating Wires at Subscriber Sets
a. Fastening Wire. No fasteners in or at the subscriber set are required if no strain is placed on the conductors at the set terminals or if the wire is concealed at the subscriber set (when the set is mounted in a bell box or when the wire is run through a partition directly to the set). If the conductors are subject to strain, place a cleat on the surface inside the set or on the backboard behind the set. If wire is not concealed at the subscriber set, place a fastener within 2 inches of the set.
b. Terminating Wire. (1) Pull wire tight and cut off each conductor 3 inches beyond the far end of its associated terminal, allowing 2 inches of slack in the wire inside the set, and 1 inch for connecting conductors to associated terminals. Skin the insulation off the end of each conductor and place the bared end three-quarters of the way around the screw, in the direction that the screw tightens. Insulation should be % inch from the edge of the screwhead.
(2) When terminating cords in subscriber sets which are equipped with screw fasteners, fasten the stay hook on the cord to the screw eye or eyelet. (See fig. 100.)
(3) When terminating cords are provided with tie-strings, tie the tie-string to the screw eye provided in the telephone set. If a small eyelet is provided in the telephone set for use with cords with stay hooks, pass the tie-string once through the eyelet and tie the tie-string to the end of the cord with several cable-form stitches.
(4) When terminating cords with tie-strings in metal subscriber sets without screw eyes or eyelets for securing cords, tie the tie-string around the terminal screw and to the end of the cord with several cable-form stitches placed close together.
(5) In case it is difficult to fasten cords with any of the methods described above, fasten the cord in the subscriber set so that—
(a) Possible interference with the ringers, etc., will be avoided.
(b) There is no strain on the free conductors.
(c) The stay hook or stay hook collar cannot short-circuit terminals in the subscriber set, or cause a cross between a terminal and the metal case of the set either directly or through some other metal part in the set.
(6) Figure 100 shows typical examples of a cord terminated in a subscriber set.
26. Testing
a. General. To make sure that the substation is in good working order upon the completion of an installation, the installer should perform ringing, transmission, and noise tests with the wire chief or switchboard operator.
b. Transmission tests.. (1) When testing wall sets, adjust the tiansmitter so that it is tilted up as far as possible. With desk sets make the test with the handle in a vertical position.
90
Sets with Sets with
Bakelite Covers Metal Covers
L2
L? / Gnd X - LzX-Zx/x
. / ,.....:Z H
1 1 iwa j J I
n ?^ Switchhook Spring Operating Post and Screw
Switch hook Lever Lift Spring
IWIp® ' J
=t=4
[I
TL-9295
Figure 108. Outdoor set.
35. Loud-ringing Bells
a. General. Loud-ringing bells are special telephone ringers installed in warehouses, factories, storerooms, etc., where the ordinary telephone ringer might not be heard above the normal noise level.
b. Description. Various types of loud-ringing bells may be used in specific situations. Some loud-ringing bells operate on normal ringing current; others, through a system of relays, operate on alternating current at 110 volts. The type of installation determines the type of bell to be used. A typical loud-ringing bell is shown in figure 109.
c. Installation. Locate a loud-ringing bell where it is most likely to be heard by the personnel for whom it is intended. In most cases, connection to the telephone consists of bridging across the ringer in the subset.
96
Pivot Screw
Yoke
Armature
Non-freezing Disc
-—Coil
Core
yy— Heel Plate
Gong Post----
Clapper Rod
Gong
Gong Mounting Screw
Permanent Magnet-Biasing Bracket Screws (a)^ P-108455
Biasing Bracket (a) P-108456
Biasing Spring Hook
[Biasing Spring (a) P•2900651
(.Biasing Cord (a)-
Biasing Stud (a)------
P-108457
Lock Washer
Clapper Ball fL 9296
Figure 109, Loud-ringing bell.
97
TL92961
SECTION VII
SUPPLEMENTARY DATA
36. Tools
The following tools are used in substation installation:
Name and description Signal Corps
Stock No.
Belt, body, lineman’s Blade, for braid stripper Blade, hack saw 604523A 6R41701-1 6Q8010-24
Brace, ratchet, loin sweep 6Q13010
Chisel, wood, %-inch 6Q21112
Climbers, lineman’s 6Q28315
Drill, automatic 6R19100
Drill, installer’s, % x 24-inch 6Q5906-24
Drill, masonry (short), M-in ch 6Q34904-4
Drill, masonry (short), 5/16-inch Drill, stone, star point, diamond, % x 12-inch File, round, half, 3-inch 6Q34905-4-14 6Q35210-12 6Q38120-3
File, flat, smooth, 8-inch 6Q38034-8
Flashlight, angle 6Z4002.1
Frame, hack saw 6Q41000
Gloves, rubber, lineman’s 6Z4829-10
Hammer, drilling Hammer, riveting, 7-ounce Hand line, aerial Holder, drill, Type C Knife, lineman’s 6Q49001 6Q50007 6Z7904A 6Q52019 6Q60229-1
Pad, climber’s, plain 6R2244
Pliers, cutting, side, 6-inch 6R4513
Pliers, longnose 6R4626
Point, drill, automatic, 5/64-inch 6Q34900/2
Point, drill, automatic, 3/32-inch 6Q34900/3
Point, drill, automatic, J^-inch 6Q34900/5
Point, drill, automatic, 11/64-inch 6Q34900/8
Rule, measuring, Stanley, 6-foot Saw, keyhole 6R9623 6R10412-8
Screw driver, cabinet, 3^-inch 6R15410
Screw driver, cabinet, 6)^-inch 6R16250
Screw driver, 4-inch 6R15680
Screw driver, 5-inch 6R15811
Screw driver, 8-inch 6R16420
Strap, climber’s, 22-inch 6R31045.1
Strap, climber’s, 26-inch 6R31045.2
Strap, lineman’s, safety 6R32500
Stripper, braid 6R41701
Tool, No. 63 open end wrench 6R40863
Tool, No. 110 double end socket 6R40910
Tool, No. 129-B open end wrench 6R40929-B
Tool, No. 216-B double end socket wrench and screw
driver 6R41016
98
Name and description
Tool, No. 265-B contact burnisher Tool, crimping (Nicopress 17-2) Twister, sleeve LC-24
37. Materials
Signal Corps
Stock No.
6R41065B
6R38500
6Q27024
The following materials are used in substation installation:
Anchor, hammer drive, y x 1-inch 6Z284-4
Anchor, machine bolt, 6-inch 6Z308-6
Anchor, wood-screw, y x 1-inch (No. 5 to No. 8 screw) Anchor, wood-screw, 3/16 x 1%-inch (No. 9 to No. 12 6Z322-3
screw) Anchor, wood-screw, y x 134-inch (No. 14 to No. 16 6Z323-4
screw) 6Z324-6
Block, 42-A, connecting 4B202
Block, 26-A, protector 4E926
Block, 27-A, protector 4E927
Block, 30, protector 4E930
Bolt, toggle, 34-inch 5B1708-5
Bolt, toggle, 3/16-inch 5B1703-5
Bolt, toggle, 34-inch 5B1704-4
Bolt, toggle, 5/16-inch 5B1705-5
Bracket, corner “L” 5B2372.1
Bracket, corner “S” 5B2372
Bracket, house 5B2365
Clamp, drop wire Type “P” /5B3084
Clamp, ground 5B3349
Clamp, ground, station 6Z1906
Clamp, span, Hubbard 8917 5B3520
Cleat, fiber, inside wiring No. 2 3G202.1
Connector, bridging, 1A 3Z1401
Connector, bridging 3A 3Z14.3
Fuse, Cook, A-7 3Z2427
Fuse, 7-A 3Z2107A
Fuse, 7-T 3Z2107T
Fuse, 11-0 3Z111C
Hook, drive, Hubbard 1316 5B5081
Hook, guardarm, Hubbard 9245 5B4725
Knob, “C”, IN-74 3G574
Knob, “S”, IN-75 3G575
Knob, “T”, IN-77 3G577
Nail, inside wiring, 34-inch 6L32009
Nail, inside wiring, J4-inch Nail, roofing, 1-inch, No. 12 6L32010
6L2001
Nail, slating, 6d 6L1406
Nail, staple, insulated 6L31006
Protector, Cook B-7 5C2200
Protector, “0” 5C2209
Ring, bridle, “A”, l^-inch eye, wood-screw thread 5B9326
Ring, bridle, “C”, 134-inch eye, wood-screw thread 5B9320
Ring, bridle, “E”, 134-inch eye, toggle 5B9310
99
Name and description
Ring, bridle, “M”, machine screw thread
Ring, drive, ^-inch, National
Rod, ground
Screw, angle, 5/16-inch
Screw, angle, %-inch
Screw, lag, 34 x 234-inch
Screw, machine, 10-inch—24 x 1 inch long
Screw, wood, R. H., %-inch, No. 6, blued
Screw, wood, R. H., 1-inch, No. 6, blued
Screw, wood, R. H., 134-inch, No. 6, blued
Screw, wood, R. H., 134-inch, No. 6, blued
Screw, wood, R. H., 2-inch, No. 6, blued
Screw, wood, R. H., 2)4-inch, No. 6, blued
Screw, wood, R. H., 34-inch, No. 8, blued
Screw, wood, R. H., %-inch, No. 8, blued
Screw, wood, R. H., 1-inch, No. 8, blued
Screw, wood, R. H., 134-inch, No. 8, blued
Screw, wood, R. H., 134-inch, No. 8, blued
Screw, wood, R. H., 2-inch, No. 8, blued
Screw, wood, galv. R. H., No. 10, 234-inch
Screw, wood, galv. R. H.,.No. 10, 3-inch
Screw, wood, galv. R. H., No. 14, 1-inch
Screw, wood, galv. R. H., No. 14, 134-inch
Screw, wood, galv. R. H., No. 14, 134-inch
Screw, wood, galv. R. H., No. 14, 2-inch
Screw, wood, galv. R. H., No. 14, 234-inch
Screw, wood, galv. R. H., No. 14, 3-inch
Screw, wood, galv. F. H., No. 18, 234-inch
Screw, wood, galv. F. H., No. 18, 3-inch
Solder, rosin core
Tape, friction, black, %-inch
Tape, rubber, black, ^4-inch
Telephone, desk type, W. E. 302AW-3 (antisidetone)
Telephone, wall, W. E. 1553-A (sidetone)
Telephone, wall, Kellog 9917 (antisidetone)
Thread, linen, waxed
Tube, porcelain, %-inch
Tube, porcelain, %-inch
Tube, porcelain, 1-inch
Washer, round, 7/16 x 1-inch
Washer, round, 9/16 x 134-inch
Wire, W-33, 19-gauge B.&S., twisted pair
Wire, W-38, 17-gauge B.&S., twisted pair
Wire, W-50, 14-gauge B.&S., twisted pair
Wire, W-69-A, 22-gauge B.&S., twisted pair
Wire, W-108, 17-gauge B.&S., parallel, drop
Wire, W-108-A, 18-gauge B.&S., parallel, drop
Wire, W-117, 22-gauge B.&S., twisted pair
Wire, W-118, 22-gauge B.&S., 3-conductor
Wire, W-119, 12-gauge B.&S., ground, 1-conductor
Wire, ground, 14-gauge B.&S., 1-conductor
Signal Corps
Stock No.
5B9320.1 5B9508 3Z3329 5B9789 5B9789 5B10004-2.5 6L7032-6.13 6L9706-6 6L9706-8 6L9706-10 6L9706-12 6L9706-16 6L9706-20 6L9708-4 6L9708-6 6L9708-8 6L9708-10 6L9708-12 6L9708-20 6L9710-209 6L9710-249 5B14014-8 6L9114-129 5B14014-12 5B14014-16 6L9114-209 6L9114-249 6L9018-209 6L9018-249 6N7531 6N8583 6N8594 4B5490 4B6633 4B6303BA.1 6Z8813 3G2002-4 3G2005-8. 3G2006-6 5B20080 5B20190 1B33 1B38 1B50 1B69A 1B108 1B108A 1B117 1B118 1B119
1B142
100
APPENDIX
REVIEW QUESTIONS
The questions included in this appendix are for review purposes and are listed under the headings of the sections to which they pertain.
Section I. GENERAL
1. Name three types of drop wire.
2. Give four general uses of drop wire.
3. What type of wire is used in completing the run from the protector to the instrument?
4. How is the tracer designated in this wire?
5. What is the difference between Wire W-38 and Wire W-50?
6. Which is the heavier gauge of the two types of twisted-pair drop wires?
7. How many protectors can be grounded to a water pipe when No. 14 B.&S. gauge ground wire is used for running the ground?
• 8. What other gauge wire is commonly used for grounding purposes?
9, What should be done if a kink develops in a drop wire and is pulled tight?
10. Is a span of parallel wire required to have any twists in it?
11. Give three general rules to follow in splicing drop wire.
12. What tool is used to remove braid from Wire W-108?
13. How much braid is removed?
14. By approximately how many inches are the splices staggered?
15. How many half turns are taken in the sleeves?
16. How many turns are taken in the buttons at the ends of the sleeves?
17. Why is it necessary to exercise care in measuring lengths, etc., when splicing drop wire?
18. What tool is used to twist up the sleeves?
Section II. OUTSIDE INSTALLATION
19. Of what two parts does the drop wire clamp consist?
20. To which part is the copper loop attached?
21. For what is the drop wire clip used?
22. What is the maximum pull allowable on a clip?
23. If this maximum pull is exceeded, what should be done?
24. What piece of liardware is usually used to support a clamp or a clip?
25. Are any tools necessary to install a clamp?
26. Is the “S” knob a single or a double-groove knob?
27. Is it permissible to mount two “T” knobs on one house bracket in a heavy loading area?
28. How many wood screws are required to mount a house bracket on a wood surface?
29. How many wood screws are required to mount a corner bracket?
30. How many toggle bolts are required to mount a house bracket on a hollow tile wall?
101
31. Is a masonry hook mounted in the brick itself or in the mortar between the bricks?
32. Are drive hooks installed in a straight vertical line on the same side of a pole? If not, why not?
33. V hat is the vertical clearance required between drive hooks?
34. What is the distance left from the end of a drive hook to the pole?
35. Name four methods of locating studding in buildings.
36. hat is the approximate length of the tie wire necessary to tie in parallel wire on a straight run tie?
37. Where is the straight run tie started?
38. How many turns are taken on each side of the knob when making the straight run tie?
39. How is the straight run ended?
40. Is the corner tie made in the same manner as a straight run tie? .41. hat two types of dead-end ties may be made in parallel drop wire?
42. Are dead-end ties in parallel and in twisted-pair wires made in the same manner?
43. When a single or double tie is made on a “T” knob, is one conductor of the twisted-pair wire placed in each groove of the knob or are both conductors placed in the same groove?
44. How much braid is retained on Wire W-108 when it is to be connected to a terminal pair?
45. If a wire is to be terminated on the left side of a terminal can and runs down from above the terminal, on which side of the terminal can is the wire brought down?
46. On which lug of the terminal pair is the tracer wire terminated?
47. How many bridle rings are installed at the base of “F”-type cable terminals?
48. If, after a drop is installed, it is found to be too short to reach the terminal pair, where is the splice made to extend the drop?
49. When attaching a wire to a terminal lug, how far should the insulation be kept from the washer?
50. Should two wires placed on the same lug be placed under a single washer?
51. If the same terminal pair serves more than two drops, how is the third drop connected?
52. How should this third drop be run with relation to the other two drops?
53. ’Is it permissible to place drive hooks both above and below the cable, for drop wire supports?
54. Should the drop wire always be fed through the drive hook?
55. When running drops from a guardarm, are the drops run through the guardarm hook?
56. To what are the drop clamps attached on a pole that contains a guardarm?
57. What piece of hardware is used in making this attachment?
58. When placing drop wire along a lead of poles containing no cable, what factor should be kept in mind with reference to the height the drop wire is placed?
59. When drop wire.is run along a lead where cable is installed, on which side of the pole is the drop run?
102
60. What determines the number of drop clamps that may be placed on one drive hook?
61. Where trees or other obstructions prohibit a direct run from a pole which contains cable, how is a drop taken from the lead?
62. How are drop connections made to open wire runs?
63. How many men are required when drops are being run over power wires?
64. What precaution should be taken when drops are being run over power wire? «
65. May the regular drop wire clamps and clips be used for tree attachments?
66. What should be done before starting work on a building drop run?
67. Should drop wires ever be run diagonally across a building?
68. Give three methods of turning a corner on a building run.
69. How many rings are required to turn an inside corner?
70. How may an inside corner be turned without the use of rings?
71. What should generally be the distance between the last point of attachment on a building run and the point of entrance?
72. How should drop wires be protected from abrasion, when contact with some object is unavoidable?
73. Should an installer have specific information as to type of circuit carried on poles which he must use to install a drop wire?
74. Under ordinary conditions should any telephone construction be placed on high-tension pole lines?
75. Give two examples of high-tension circuits.
76. What is the clearance required for line drops over trolley feeders?
77. Is there any standard clearance for navigable streams?
78. What is the clearance required over residence driveways?
79. What is the clearance between vertical runs on poles?
80. When drops are run from a pole, should the drops leave the pole in a direct lead on the field side?
81. Define climbing space.
82. Why is climbing space provided?
83. What clearance must be provided over a sidewalk?
Section III. STATION PROTECTION
84. Are protectors a primary or secondary protection for substations?
85. If protectors are not the primary means of protection, what is?
86. Give two general classifications of telephone construction with reference to installation of protectors.
87. In which of these two types would protectors be installed?
88. Give one general definition of an exposed area.
89. Give one general definition of an unexposed area.
90. What is the minimum distance to be left between centers when installing substation protectors?
91. How is the metallic connection made between the two porcelain sections of a protector?
92. What capacity or types of fuses are used in protectors?
93. Should protectors be installed on the outside or inside of buildings?
94. Give the main point to be considered when locating a protector.
103
95. At what minimum height from the floor should protectors be installed?
96. Is it permissible to install protectors on an inclosed porch?
97. Should protectors be installed horizontally?
98. How is a drop insulated where it enters a frame building?
99. What size tube insulator will accommodate two drops?
100. Should the hole drilled for a porcelain tube insulator be on a horizontal plane?
101. May the porcelain tube insplator be omitted when the drop enters a brick building?
102. If no tube insulator is used, what protection is given the drop wire where it enters a brick building?
103. Is it permissible to use a ground w’ire made up of several sections of wire soldered together?
104. Can a ground wire run be concealed?
105. Is it necessary to thoroughly insulate foreign wires from ground wires?
106. Is it permissible to install ground wire on knobs?
107. How are ground wires fastened to water pipes?
108. Which is the preferable ground, a hot or a cold water pipe?
109. When attaching ground wire to a ground rod, should the joint be soldered?
110. Should the top of a ground rod protrude above the surface on the ground?
111. Is it permissible to place ground rods in cellars that have an earth floor?
112. Should a water pipe be cleaned before a ground clamp is installed?
Section IV. INSIDE INSTALLATION
113. May inside house wire runs be concealed?
114. Should inside house wire runs be made diagonally, as a general rule?
115. Should inside house wire be run in damp places?
116. What clearance is required between an inside house wire run and an open electric light wire run?
117. May inside house wire be run through floors without added insulation?
118. May inside house wire be run through woodwork without added insulation?
119. What spacing is required when inside wire cleats are used?
120. Is it permissible to splice inside house wire?
121. Name one condition in a new installation under which a splice is permissible.
122. , Name one condition in a reinstallation under which it is permissible to make a splice.
123. Is it necessary to solder the splice made in inside house wire?
124. When connecting wire to the protector, what is the distance required from the lug to the point where the insulation has been cut and removed from the wire?
☆ 591782—44
104
NTSU LIBRARY
UNT LIBRARIES DENTON TX 76203 llllllllllll lllllllllllll 1001896184