[Inspections and Preventive Maintenance for Electrical Facilities] [From the U.S. Government Publishing Office, www.gpo.gov] Document "A l~ I ' fTt} fTPl ■ R“™ ml mum WAR DEPARTMENT TECHNICAL MANUAL e NON-CIRCULATING INSPECTIONS AND PREVENTIVE MAINTENANCE FOR ELECTRICAL FACILITIES WAR DEPARTMENT • AUGUST 1945 WAR DEPARTMENT TECHNICAL MANUAL TM 5-681 INSPECTIONS AND PREVENTIVE MAINTENANCE FOR ELECTRICAL FACILITIES WAR DEPARTMENT AUGUST 19 4 5 United States Government Printing Offici Washington: 1945 WAR DEPARTMENT Washington 25, D. C., 31 August 1945 TM 5-681, Inspections and Preventive Maintenance for Electrical Facilities, is published for the information and guidance of all concerned. [AG 300.7 (7 May 45)] By order of the Secretary of War : G. C. MARSHALL Chief of Staff Official : EDWARD F. WITSELL Major General Acting The Adjutant General Distribution : ASF (2); Tech Sv (2) except OCE (75) ; S Div ASF (1) ; Sv C (10) ; Air Tech SvC (10); ATC (10) ; PC&S (5) ; Dist O 5 (2); Div Eng (10) ; USMA (2) ; 1st, 2nd, 3rd, 4th AF (10). NO OVERSEA DISTRIBUTION. Refer to FM 21-6 for explanation of distribution formula. il CONTENTS SECTION I. GENERAL Purpose and scope................................................ 1 1 Maintenance responsibility....................................... 2 1 Inspection and maintenance records............................... 3 1 II. PREVENTIVE MAINTENANCE SERVICES AND TECHNICAL INSPECTIONS OF ELECTRICAL SYSTEMS. Transformer substations ......................................... 4 5 Auxiliary power sources ......................................... 5 12 Underground distribution systems................................. 6 12 Overhead distribution systems.................................... 7 19 Street-lighting systems ......................................... 8 28 Building systems and equipment................................... 9 31 Disposition of work sheets...................................... 10 35 III. PREVENTIVE MAINTENANCE SERVICES AND TECHNICAL INSPECTIONS OF ELECTRIC MOTORS. General ........................................................ 11 36 First echelon preventive maintenance ........................... 12 36 First echelon preventive maintenance by unskilled users......... 13 36 First echelon preventive maintenance by plant operators, inspectormechanics, or other skilled users............................... 14 36 Motor or generator record cards................................. 15 37 Work sheet for motors and preventive maintenance instructions.... 16 38 Disposition of work sheets...................................... 17 44 in SECTION I GENERAL I. Purpose and Scope This Technical Manual provides the basis for a properly coordinated maintenance program for electrical systems used on Army posts. It outlines the necessary tests, inspections, and servicing procedures and explains the preventive maintenance forms and records that are used. Frequencies recommended for inspections and services are minimums. If maintenance problems are complicated by severe service or unusual atmospheric conditions, more frequent inspections may be scheduled on approval of the service command or Air Force command. For further details on safety procedures and on operation, maintenance, and testing of electrical equipment found on Army posts, see TM 5-680 (when published). 2. Maintenance Responsibility a. Unit commander. Commanding officers of using organizations are responsible for insuring that electrical facilities are kept in good physical condition and are protected from damage and vandalism. They must also make certain that the post engineer is notified promptly of all operating deficiencies. b. Maintenance personnel. Inspections and preventive maintenance services are performed in the lowest echelon which has the necessary tools, parts, qualified electricians, and available manpower. Each echelon must be so thoroughly trained in its responsibilities that it applies them automatically. This manual may not include detailed maintenance instructions for all electrical equipment on every post. The lack of information on a particular piece of equipment does not relieve maintenance personnel of the responsibility for all necessary inspections and services. General responsibilities include : (1) Inspecting, repairing, and protecting electrical facilities and preventing unnecessary deterioration. (2) Keeping electrical equipment clean, lubri cated, and in proper operating condition. (3) Checking the condition and security of supporting members and connections of all equipment inspected. (4) Correcting defects on discovery or properly reporting them to a higher echelon. c. Electrical supervisor. The electrical supervisor is responsible for— (1) Scheduling regular inspections and preventive maintenance services and assigning qualified personnel to the job. (2) Issuing repair orders and seeing that they are carried out. (3) Keeping adequate, up-to-date records of inspection and maintenance. (4) Continuously checking the work of maintenance personnel. d. Post engineer. The post engineer is responsible for— (1) Coordinating maintenance operations with needs of using organizations to insure minimum interruption of electrical service. (2) Conformance to rules on safety and clearances stated in the National Electrical Safety Code, fifth edition, published by the National Bureau of Standards. (3) Setting up a file of manufacturers’ bulletins for all electrical equipment on the post. (4) Using the services and experience of serving utilities. (5) Insuring satisfactory performances of the over-all maintenance program. 3. Inspection and Maintenance Records The forms discussed below are specially designed to help post engineer personnel do their work. a. Work sheets. Work sheets are provided for the various sections of the electrical system. (See figs. 2, 4, 9, 10, 12, and 15.) Their use insures uniform maintenance practices by post engineer personnel. (1) Description. Each work sheet lists the I 2 necessary inspections and services for a particular section of the electrical system, identifying each operation by an item number. The location of a rectangular check space in the time-schedule columns alongside the list determines the minimum frequency for performing each operation. (2) Use. (a) Inspectors are responsible for servicing equipment and for making appropriate entries on the work sheet. Before starting his inspection, he enters his name, the date, and location of equipment to be serviced. As he completes each step in the maintenance procedure, he marks the check space with one of the following. 1. V if equipment is found satisfactory. 3. X if adjustment is required. 3. XX if repair or replacement is necessary. (b) If adjustment or repair is needed and the inspector makes the correction, he circles the X or XX thus: ® or (XX) »If he does not correct the defect immediately or if correction is to be made by higher echelon, he enters a full explanation in the space for remarks, including the item’numbers to identify defects involved. The electrical supervisor has the necessary work orders issued to complete higher echelon repairs. Item numbers are included to identify any defects so noted. (3) Relation to manuaL This manual includes a paragraph for each section of the electrical system covered by st 'Work sheet, and explains operations listed on' the work sheet. To simplify cross reference the manual explanation and corresponding work-sheet operation have the same identifying item number. As an additional guide, the manual also contains time-schedule columns, and indicates frequency for each maintenance step by location of the item number in these columns. b. Preventive maintenance schedule. WD AGO Form 5-91 (Preventive maintenance schedule for electrical facilities) (fig. 1), is a yearly consolidated record of the post maintenance program. The electrical supervisor makes necessary entries on the form, taking his information from the work sheets. If the work sheet shows that a necessary repair or adjustment had not been completed, the electrical supervisor draws a diagonal line through the check space on the preventive maintenance schedule, thus: . When repairs are completed, he marks the space thus:|^><(]. He uses the same marking if the inspection showed that no repairs were necessary. The electrical supervisor keeps the form posted conspicuously in his office where it can be referred to or inspected at any time. On the first of each year, he prepares and, posts a new form, entering in the fourth column (fig. 1) the date each item was last inspected. This helps in preparing work schedules, since reference to the third and fourth columns shows immediately when the next inspection of each item is due. c. Record cards. The electrical supervisor keeps a file of the following permanent record cards for each transformer, motor, and building wiring system maintained by post engineer personnel: WD AGO Form 5-82 (Transformer record card) (fig. 3); WD AGO Form 5-84 (Building electrical inspectors’ record) (fig. 11) ; and WD AGO Form 5-83 (Motor or generator record card) (fig. 14). Instructions on using these forms are given in appropriate paragraphs of sections II and III. d. Daily log. The electrical supervisor also keeps a daily record of major incidents affecting the post electrical facilities. For example, he would list primary distribution outages affecting one or more transformers or the main source of supply. The entry would include the cause of the outage, when it occurred, and its duration. Any convenient form or notebook can be used for this log. 3 W.D.,A.G.O. FORM NO.5-91 PREVENTIVE MAINTENANCE SCHEDULE FOR ELECTRICAL FACILITIES CALENDER YEAR 19- SYMBCLS:- INDICATES THAT SCHEDULED INSPECTION mas BEEN MADE. . tSJ- INDICATES THAT NECESSARY REPAIRS HAVE BEEN COMPLETED, OR THAT NO REPAIRS ARE NECESSARY. * - THIS SCHEDULE COVERS A CALENDAR YEAR. START A NEW SHEET FOR EACH YEAR AND BRING FORWARD THE LAST INSPECTION DATE IN THIS BLOCK. ELECTRICAL FACILITIES ITEMS INSPECTION PERIOD LAST INSPEC. BROUGHT FWO.« JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV OEC ELECTRICAL FACILITIES ITEMS INSPECTION PERIOD LAST INSPEC. BROUGHT FHD.♦ JAH FEB MAR APR HAY JURE JULY AUG SEPT OCT NOV DEC TRANSFORMER SUBSTATIONS GENERAL APPEARANCE ARRESTERS BUSHINGS & INSULATORS Cracked or broken Clean CONNECTIONS GROUNDS Grounds to equipment Accidental grounds OIL CIRCUIT BREAKERS OIL CHECK AND TESTS POLE TOP SWITCHES REGULATORS Oil level, etc. Operating mechanism, etc. Arcing of contacts, etc. Loose Bolts and Nuts transformers Temperature, etc. Fused disconnects UNIT TYPE SUB-STATIONS Clean, etc. Manufacturers Inspection LOAD TESTS 1- 6 incl. 7-11 incl. 12 13 IN, 15 16-20 incl. 21 22-31 incl. 32-36 incl. 37-42 incl. 43.44 45-48 incl. 49-51 incl. 52 53-56 incl. 57 58-61 incl. 62 63-65 incl. Month Year Month 2 Years 2 Years 2 Years 6 Months 2 Years Year 2 Years Month 6 Months Year 5 Years Month 2 Years Month 5 Years Year STREET LIGHTING SYSTEMS (Cant’d.) LAMPS Weekly Patrol Series Group Replacement Multiple Replacement 7 8 9 Week 2000 Hrs. 2000 Hrs. 1 IIII 1 Illi l_ll JJ-L II! ill in Z! ILL HI 1 1 1 1 BUILDING SYSTEMS A EQUIPMENT WIRING SYSTEMS DISTRIBUTION PANEL Fuses, etc. General Inspect!oft 4£d Grounds Grounded Neutral LIGHTING FIXTURES 1- 3 incl. 4- 6 incl. •4-8 incl. 9 10-12 incl. Year 3 Months Year 5 Years 3 Months 1 1 1 1 • > ‘ —• 1 -- ‘ ' EZZZ 1 1 1 I 1 C.LLCIKIV MUIUKo UK SLEEVE BEARINGS A LUBRICATION Oil seals, etc. Belt, chain or Gear Pressure, etc. Lubrication - Oil level Lubrication - Oil Reservoir BALL OR ROLLER BEARINGS A LUBRICATION Vibration A Temperature, etc. Lubrication- Oil Lubrication- Grease BRUSH AND BRUSH HOLDERS Clean A check Length, etc. COMMUTATOR OR SLIP RINGS Clean Mica, High Bars, Uneven wear ROTORS PROTECTIVE DEVICES A CONTROLS TESTS Load check Clearance - Rotor A Stator, etc. MISCELLANEOUS CHECKS Motor Temperature, etc. Electrical Connections, etc. Motor mounting Clean, Blowout Windings Generators* ’ Storage Batteries 1- 3 incl. 4-6 incl. 7 7 8-11 incl. 12 12 X3 14,15 16 17 18,19 20,21 22 23.24 25-27 incl. 28,29 30 31 u__ Month 6 Months Month 6 Months Month Month 6 Months Month 6 Months Month 6 Months Year 6 Months 6 Months Year Mon Hi 6 Months Year 6 Months* Month 1 l 1 1 .. 1 > 1 1 1 11. 1—J • 1 ■ 1' I 1 IIIII 1 1 UNDERGROUND DISTRIBUTION UNDERGROUND SYSTEM MAN-HOLES CABLES JUNCTION BOXES - CABLE Gaskets, etc. Air Pressure POTHEADS transformer vaults TRANSFORMERS Load Test - No change in loading Load Test - Change in loading Oil Test 1- 7 incl. 8-13 incl. 14-16 incl. 17 18-21 incl. 22-29 incl. 30 31 32.33 Year Year Year Month Year Year 5 Years Year 5 Years ! 1 1 J r [ 1 1 i 1 1 i • 1 Illi 1 I 1 1 1 1 1 1 1 1 1 1 _ 1 1 1 1 1 1 ! 1 r I 1 I I 1 1 1 1 1 1 OVERHEAD DISTRIBUTION ARMS. PINS A WOOD STRUCTURES Visual from ground Climbing Inspection ARRESTERS Visual from ground Climbing Inspection BOLTS A BRACES BUILDING SERVICES CUTOUTS Visual from ground Climbing Inspection FUSED A UNFUSED DISCONNECT SWITCHES GROUNDS GUYS A ANCHORS INSULATORS Visual from ground Climbing Inspection LINE WIRE POLES, WOOD Untreated Butt-Treated - splitting, leaning-,, buckling Butt-Treated - heart Fot Full creosoted Poles - splitting, leaning, buckling Full creosoted Poles - heart Fot transformers - distribution Load Test - No change in loading* Load Test - Change in loading Connections, etc. tree TRIMMING VOLTAGE TESTS 1 2 3 4 5 6 7 8 9 10 11 12 13 14-16 incl. 17 18 18 19 19 20 21 22-24 incl. 25 26,27 Year 5 Years Year 5 Years 5 Years Year Year 5 Years 2 Years 2 Years Year Year 5 Years Year Year Year 5 Years Year 5 Years 5 Years Year 5 Years Year 5 Years 1 1 1 1 : ii । 1 i r- 1 1 i ■■ 1 1 ■ ' ■ ■■■ * * « ■ ■ ■ A 1 ■* MAPS A RECORDS REVISIONS TO DATE 3 Months 1 1 1 L__i I LZZJ ZZ r. J । j. । i i । i i । । i l__J 1 - . ! 1 l 1 1 1__! 1L_1 I I 1 1 II 1 1 I 1 1 1 1 1 1 ' I liilli i 1 l l 1 1 1 I 1 1 1 j 1... 1 1 1 1 1 II 1 III! l_ 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 J I- 1 i i i l l i i 1 1 1 1 1 __l 1 1 1 1 1 1 1 I I । ~ 1 1 1 1 1 II 1 1 1 J J L_ 1. .1 1 1 1 1 1 1 1 1 1 1 L.. 1 Illi li i ' 1 1 1 1 1 i i I i i i i l l i t l I 1 1 1 1 ! II 1 Illi 1 1 ... 1... .1 .. i 1 1 1 1 1 1 1 ! ! 1 1 I 1 1 1 1 1 1 1 1 1 1 1 '1 1 1 1 1 1 1 1 1 1 1 1—1 1 fl 1 Illi L 1 I. 1 i i 1 1 1 1 I 1 1 1 I . 1 III 1 T 1 1 ~l ..iiiii iii iiin _J i ii i. i i i i i i—i i i i i iiii i i ii STREET LIGHTING SYSTEMS CONSTANT CURRENT TRANSFORMER CONTROL EQUIPMENT Oil Switch Oil Renewal TIME CLOCKS Check and reset Check Contacts Clean and overhaul PHOTO CELL CONTROL FIXTURES A MOUNTING BRACKETS 1 2 2 3 3 3 ’ 4 5,6 Year Year 2 Years Month Year 5 Years Year Year i i । 1 । fill "~r- 'i i - i i i i । i i i i i i i 1 1 I 1 I L__J Illi! i i i । iii i ii ii 1— 1. 1 II 1 1 1 1 1 11 .IIIII 1 1 1 1 1 1 1 L_.. 1 1. . 1 1 III 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 NOTES:- More frequent inspections may be necessary at some Posts because of particularly corrosive atmosphere, unusual operating conditions, frequent storms, etc. Inspection periods may be shortened or lengthened at the discretion of tie Service Command Engineer. An additional inspection of an oil circuit breaker may be required after it has opened to clear a fault SPECIAL INSTRUCTIONS: Sao TM 5-631 far Detailed Initraction: a Proeodurat. Soo Mfr. Manual for Technical In format ion. Figure 1. SECTION II PREVENTIVE MAINTENANCE SERVICES AND TECHNICAL INSPECTIONS OF ELECTRICAL SYSTEMS 4. Transformer Substations a. General. Responsibility for maintaining post transformer substations depends on whether they are the property of the government or the serving utility. (1) Government-owned. Government-owned substations are maintained by the post engineer’s electrical staff; only competent skilled personnel are used for this work. If no skilled personnel are available on the post, the post engineer sets up a list of off-post personnel on whom he can call for routine and emergency maintenance. The post engineer keeps records of all work done by such personnel. (2) Utility-owned. The serving utility maintains post substations which it owns. Information received by the post engineer concerning operation or maintenance of a utility-owned substation is referred to the utility through established channels. b. Inspection and maintenance instructions. Maintenance required for transformer substations is outlined on WD AGO Form 5-87 (Work sheet for substation inspection and preventive maintenance services) (fig. 2), and in the supplementary instructions below. For instructions on using the work sheet, see paragraph 3a. Caution: Inspector must always be accompanied by a qualified electrician when inspecting substations. Monthly and semiannual inspections do not require handling high-voltage equipment. For all other inspections, the station must be deenergized and effectively grounded (see discussion of safety requirements, TM 5-680). Switch stick or hot-line tools stored at the substation must be checked at each monthly inspection. 5 6 fo^\o.5-87 WORK SHEET FOR SUB-STATION INSPECTION NOV; 1944 AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See TM 5-681 For Detailed Instructions & Proeedures.See Mfr. Manual for Technical Information. LOCATION DATE 1 NSP ECTOR LEGEND FOR MARKING SYMBOLS SATI SFACTORY x ADJUSTMENT * ~ REQUIRED REPAI RS OR XX- REPLACEMENT DEFECT 0 - CORRECTED 1 ] — INSflECT AND CORRECT 1 YEAR EARANCE 1 YF»R r 1 6 MONTHS 6 MONTHS MONTH MONTH ▼ GENERAL APP r ♦ ▼ OIL CHECKS AND TESTS 1 2 3 4 5 6 FENCE WARNING SIGN GATES (Fastened and locked) DOORS - WINDOW AND BUI LDING WEEDS AND TRASH EQUIPMENT PAINTED 32 33 34 35 36 MOI STU RE CARBONI ZATION DI RT AND SLUDGE INTERIOR OF EQUIPMENT TEST POLE TOP SWITCHES ARRESTERS ■ "■ 37 38 39 40 41 42 CLEAN AND ADJUST GREASE OPERATION ARCING HORNS LOCKED GROUND AND GROUND RESISTANCE 7 8 9 10 11 LOOSE CONNECTIONS CHIPPED, SHATTERED, CRACKED CONNECTIONS TO GROUND CL EARANCES CHECK FOR CLEAN SURFACE BUSHINGS AND INSULATORS REGULATORS 12 13 CRACKED OR BROKEN CL E AN 43 44 45 46 47 48 49 50 51 OIL LEVEL □ CRACKED OR BROKEN BUSHINGS OPERATING MECHANISM MOTOR LUBRI CATION CONTACT MAKING VOLTMETER ARCI NG OF CONTACTS LIMIT SWITCHES MOTOR CONTROL RELAY LOOSE NUTS AND BOLTS CONNECTIONS — 14 15 LOOSE DEFECT!VE GROUNDS TO 16 17 18 19 20 21 TRANSFORMER TANK SWITCHG EAR HOUSING OP ERATING LEVER LIGHTNING ARRESTERS METAL FENCE ACCI DENTAL GROUNDS ON UNGROUNDED SYSTEMS EVERY 5 YEARS 52 TRANSFORMERS 53 54 55 56 57 TEMPERATURE COOLING .EQUIPMENT OIL CIRCUIT BREAKERS 22 23 24 25 26 27 28 29 30 31 TIGHTEN ALL NUTS AND BOLTS CONTACT SURFACES CONTACT ADJUSTMENT OPERATING MECHANISM (-Clean and lubricate) LENGTH OF BREAKER STROKES OPENING AND CLOSING SPEED OP ERATI NG VOLTAGE CLOSING RELAY CONDITION OF 01 L LEAKS OIL LEVEL ANO LEAKAGE LOAD READINGS (for loads at or above rated eapao FUSED DISCONNECTS UNIT TYPE SUB-STATION 58 59 60 61 CLEAN COMPARTMENTS STORAGE BATTERIES ANO CHARGER OIL LEVEL AND TEMPERATURE INERT GAS PRESSURE MANUFACTURER’S INSPECTION EVERY 5 YEARS 62 LOAD TESTS 63 64 65 LOAD TEST MAIN BUS LOAD TEST EACH FEEDER VOLTAGE TEST REMARKS AND RECOMMENDATIONS — DISPOSITION QF WORK SHEET THIS WORK SHEET SHOULD BE HELD IN THE POST ELECTRIC MAINTENANCE FILE UNTIL REPAIRS ARE COMPLETED AND INFORMATION RECORDED ON MAINTENANCE SCHEDULE W. D., A, G. 0. FORM NO. 5’91 AND ALL TEST DATA PROPERLY RECORDED. IT MAY THEN BE DESTROYED. Figure x. 7 GENERAL APPEARANCE Years__Year Months Month Keep the substation neat and clean. Maintain substation bus and bus supports in a good workmanlike manner. Increase frequency of maintenance for equipment near coastal waters or corrosive or dusty atmosphere. 1 Fence. Check condition of fences; repair and paint them when necessary. 2 Warning signs. Make sure warning signs are in proper position, one on entrance gate, one on each side of inclosure, and one attached to substation structure near parts carrying high voltage. Signs should read DANGER and should state the voltage. 3 Gates. See that gates are fastened, padlocked, and in good operating condition. 4 Doors, windows, and buildings. Check condition of switchhouse building, roof, doors, and windows, and repair if necessary. 5 Weeds and trash. Remove all trash and all grass and weeds growing within the inclosure. 6 Equipment painted. Inspect transformers, oil switches, and other equipment for cleanliness and adequacy of paint protection. 7 8 9 ARRESTERS Loose connections. Check for loose line and ground connections. Tighten all electrical connections. Caution: Equipment must be deenergized and grounding harness installed where applicable. Chipped, shattered, cracked. Examine housing for chipping, shattering, cracks, or other damage. Connections to ground. Make sure ground connections are continuous and securely fastened to grounding rods. See that grounding conductors on wood structures are protected with wood moulding to at least 8 feet above earth level. 10 Clearances. To prevent external flashovers, maintain same clearance between line terminal and grounded structures as between line conductors on the same structure. 11 Check for clean surface. Keep external surfaces of arresters clean to prevent flashovers. 12 13 BUSHINGS AND INSULATORS Caution: On visual inspection, do not touch energized equipment. For inspection 13, equipment should be deenergized. Cracked or broken. Check visually for cracked or broken bushings and insulators. Clean. Clean bushings and insulators as required by local conditions. If continuous service is necessary, get special instructions for washing insulators and bushings while circuit is energized. 8 2 Years 14 15 16 17 18 19 20 22 23 24 25 26 27 28 29 30 31 CONNECTIONS 'ear Months Month Caution: For inspections 14 through 20, equipment must be deenergized and grounding harness applied where applicable. Loose. Check connections to grounds and all equipment and make sure they are tight and well secured. Defective. Check for corroded or damaged connectors. Replace if necessary to maintain good contact. GROUNDS Grounds to equipment. Test ground resistance to all equipment. See that transformer tank, switchgear housing, operating levers, lighting arresters, and metal fencing are properly connected to station ground. Ground resistance should not exceed 3 ohms for water-pipe connections or 15 ohms for driven grounds. Use at least four ground rods. 21 Accidental grounds. Test for accidental grounds on ungrounded equip- ment. OIL CIRCUIT BREAKERS Before making the inspections below, take the breaker off the circuit and apply grounding harness. Inspect every 2 years, preferably in the spring. Inspections may be required at shorter intervals if breaker operates frequently to clear heavy fault currents. Tighten. Tighten all nuts and bolts in the mechanism. Contact surfaces. Inspect contacts and replace those badly burned or pitted. If contact surfaces are only roughened, smooth them with No. 00 sandpaper; do not use emery cloth. Contact adjustment. Check contacts for proper alignment; see that contact surfaces bear with firm uniform pressure and are properly adjusted. Operating mechanism. Make sure breaker and operating mechanism work smoothly and freely without binding and are free of dirt. Lubricate bearing points with a good grade of machine oil. Length of breaker stroke. Measure length of breaker stroke and adjust if necessary. Opening and closing speed. Check breaker opening and closing speed and adjust if necessary. Operating voltage. With full operating current flowing, check operating voltage at mechanism terminals to be sure it is adequate for correct operation. Make sure operating current is correct. Closing relay. Check closing relay for proper operation. Condition of oil. Check oil in breaker. See items 32 through 36. Leaks. Note and report any oil leaks. OIL CHECKS AND TESTS 32 Moisture, carbonization, dirt and sludge. Take sample of oil from 33 equipment, spread it in a thin coat on a bright tin surface, and inspect 9 2 6 Years__Year Months Month 34 for moisture, carbonization, dirt, and sludge. If oil shows signs of any of these conditions, filter and retest. When adding oil to electrical equipment, use same type and grade as presently in service. See discussion of insulating oils, TM 5-680. 35 Interior of equipment. Check interior of equipment. Clean if neces- sary, using new oil applied under pressure. Discard oil used for washing. 36 Test. Test dielectric strength of oil, using 1-inch disks spaced 0.1- inch apart. If oil tests lower than 18 kilovolts, filter to raise dielectric strength to 25 kilovolts. Oil removed from circuit breakers is often heavily carbonized. Therefore, unless there are large quantities of oil, filtering may not be economically feasible. POLE TOP SWITCHES Caution: Equipment must be deenergized and grounding harness applied where applicable. If switch cannot be bypassed, jumpered out, perform inspections and services below when line is taken out of service for other reason. However, interval between inspections must not exceed 2 years. 37 Clean and adjust. Clean contacts. To prevent damage, adjust so full contact can be obtained on all phases without slamming switch. 38 Grease. Grease all contacts with nonoxide grease. 39 Operation. Adjust and tighten nuts. See that all movable parts operate freely. 40 Arcing horns. Set arcing horns so they barely touch when switch is opened and closed. 41 Locked. Lock pole top switches to prevent unauthorized tampering. 42 Ground and ground resistance. Inspect for loose, broken, and corroded ground connections to operating handle. Check ground resistance, preferably in the fall. REGULATORS 43 Oil level. Check that oil level is at required height. Add oil if necessary. When adding oil to electrical equipment, use same type and grade as presently in service. See discussion of insulating oils, TM 5-680. 44 Cracked or broken bushings. Note and report cracked or broken bushings. 45 Operating mechanism. Check to see that operating mechanism func- tions according to manufacturer’s instructions. 46 Motor. Check motor for faulty starting, noisy operation, excessive sparking, loose connections, etc. 47 Lubrication. Clean and lubricate motor, using oil of proper viscosity for the climate. Clean and lubricate other moving parts as required by manufacturer’s instructions. For further information on motors, see section III. 10 2 6 Years Year Months Month 48 Contact-making voltmeter. Check voltage level of contact-making volt- meter by reading voltage on load-center testing terminals. On regulators, with line-drop compensators, turn contact arms back to zero when taking voltage measurements. 49 50 51 52 (every 5 years) 57 Arcing of contacts. Observe arcing of voltmeter contacts; if arc sputters, contacts are faulty and may need replacement. Limit switches. Observe operation of limit switches to make sure movable contacts open with a snap action and close completely. Motor-control relay. See that motor-control relay operates without chatter or sluggishness. Loose nuts and bolts. Raise interior from tank and check for loose nuts and bolts and defective contacts and bushings. Check condition of insulation on cable leads from rotor; replace if found brittle or defective. See that bearings, gears, and other operating mechanisms operate properly and are adequately oiled. Wash with new oil applied under pressure if sludge deposits are found. TRANSFORMERS 53 Temperature. Test functioning of temperature gauge by installing temperature gauge in well provided for this purpose. If test well is not provided, take tank temperature by carefully attaching temperature gauge at top of tank, below oil level. Add 5° Centigrade (C.) to tank temperature to get approximate oil temperature in tank. Test temperature of transformers operating at full load. Never allow oil temperature of oil-immersed, self-cooled transformers to exceed 95° C.; do not operate such transformers long at temperatures above 90° C. 54 Cooling equipment. Check cooling equipment on transformers for proper operation of fans and control relays or correct circulation of cooling water. Modify lubrication schedule for fan motors in accordance with severity of service performed. Caution: Observe usual safety procedures in vicinity of high-voltage wires. See TM 5-680 for safe clearance distances. 55 Oil level and leakage. Check oil level. If low, inspect all valves and tanks for leaks and make necessary repairs immediately. Keep oil at level required by manufacturer. When adding oil to electrical equipment, use same type and grade as presently in service. See discussion of insulating oils, TM 5-680. 56 Load readings. When transformers are known to be operating at rated load, or above, take ammeter readings of load at peak-load period to detect and prevent excessive overloading. Caution: Equipment must be deenergized and grounding harness applied where applicable. Fused disconnects. Examine contacts, insulators, mountings and operating mechanism. Grease noncontact surfaces with nonoxide grease. II 2 6 Years Year Months Month 58 59 60 61 62 (every 5 years) SWITCH CUBICLES, PRESSURE-TYPE TRANSFORMERS, AND UNIT-TYPE SUBSTATIONS Caution: Observe usual safety procedures in vicinity of high voltage wires. See TM 5-680 for safe clearance distances. Clean compartments. Clean all compartments. Check space in rear of switching compartment to make sure it is not used for storing mis-cellaneous items. Storage batteries and charger. Check water level in batteries and add distilled water if necessary. Check battery charger to see that it functions properly. Oil level and temperature. Check oil gauge for oil level in transformer. Check temperature indicator for signs of overload. Inert-gas pressure. Where transformers operate with inert-gas pressure in transformer, observe and record pressure-gauge readings to detect leaks and to note whether pressure meets manufacturer’s specifications. If a leak is indicated, follow manufacturer’s instructions for finding it. Manufacturer's inspection. Because the operating mechanism of a unit substation is extremely complicated, it is maintained by the manufacturers’ representatives, who make a complete and detailed check of the entire unit at least every 5 years. The post engineer arranges with the manufacturer for other necessary maintenance work. LOAD TESTS Caution: Use of rubber gloves or hot-line tools is mandatory. All energized wires, buses, etc., in reach of personnel must be protected or effectively roped off. 63 Load test main bus. Test load on main bus. A hook-on ammeter with proper hot-stick handle may be used. Rearrange load of feeders to balance phases as closely as possible at main bus. Record test results on work sheet. 64 Load test each feeder. Test load on feeders and balance phases as closely as possible. Transfer loads above-carrying capacity of a circuit to other feeders to reduce line losses and give better regulation. Record test results on work sheet. 65 Voltage test. Test supply voltage of post distribution system at the substation, using potential transformers if available, or at a nearby distribution transformer of known ratio when it is under load. Record test results on work sheet. 12 5. Auxiliary Power Sources a. General. Post engineer personnel maintain both permanently installed and portable auxiliary electrical-power sources and insure that they are always in condition for immediate use. Electrical personnel are not responsible for fuel supply, maintaining air pressure for starting or inspecting the prime mover and related equipment unless the responsibility is specifically assigned them by the post engineer. b. Inspection and maintenance instructions. For specific inspection and maintenance procedures, see section III. The work sheets and procedures for motor maintenance discussed in that section also apply to generators. To adapt these work sheets and instructions for use with generators, substitute the word generator for motor throughout the forms and text. c. Starting and operating instructions. Post instructions for starting and operating an auxiliary power plant near the equipment. Make certain that all operators memorize these instructions. 6. Underground Distribution Systems Underground distribution systems are extremely dependable and give long, trouble-free service if properly maintained. The schedule of inspections below provides good maintenance procedure and helps prevent long outages which sometimes occur in underground cable systems. a. Transformer record card. WD AGO Form 5-82 (fig. 3), is a permanent record of transformer test data. A record card is kept for each government-owned transformer in the underground distribution system, including subway-type transformers in manholes and dis-tribution-type transformers in above-ground vaults. Data are obtained from the inspectors, who give the electrical supervisor a daily list of all transformers inspected, including exact test results. The electrical supervisor enters the data on the proper record card. b. Inspection and maintenance instructions. (1) Maintenance operations for underground distribution systems are shown on WD AGO Form 5-90 (Work sheet for underground distribution and preventive maintenance services) (fig. 4), and discussed further in the instructions below. For instructions on using the work sheet, see paragraph 3a. (2 ) To help control work on extensive underground systems, prepare a system map similar to the overhead distribution map discussed in paragraph 7a. As inspection of an item is completed, check it off on the map. 13 r----------------------------------------------------------------------------------------------------------------------------- nnjttiron-------------------" ............— 1 -----------------—-------- ■ ..... form no.5-82 TRANSFORMER RECORD CARD NUMBER MAKE ' STYLE OR SPECI FICATION KVA PHASE TYPE MFRS. SERI AC NUMB ER _____________________________________________________________________ FORM___________________________________________ CYCLES DATE RECEIVED^ ACCESSORIES Kl N OOF SERVICE — . ■■■ ■! ■■ —■ .. . ,.,■■■■ _____ (________________________________________1 OUT DO 0 R * IMP._______________■ ■____________________________1 I SEMAPHORE I I THERMOM ETER I I INOOOR _____ r I SU R W A Y ___________I SEC, y _______________CZJ.Q IL_G AllGE. C~l DRAIN VALVE___________________________________ NO lOfATinM P0LE 0R DATE PHASE PRI- SEC- DATE Oru,nizo LUbA,IUN LOC. NO. INST. WIRES VOLTS VOLTS REMOVED REMARKS _J______________________________________________________________________________________________________________________ 2___________________,__________________________________________________________________________________________________ _2______________________________________________________________________________________________________________________ U_______________________________________________________T________________________________________________ 5 | I I I I I . I I _______________________________________________ CONNECTED LOAD__________________________________________________________ LOC. NO. BUILDINGS SERVED KW DATE KW DATE KW DATE KW DATE ifeteE REVERSE SIDE FOR ADDITIONAL SPACE FOR CONNECTED LOAD AND FOB LOAD TESTS) K CONNECTED LOAD (Cont’d.) LOC. NO. BUILDINGS SERVED KW DATE KW DATE KW DATE KW DATE LOAD TESTS DATE AMPERES AMPS. X VOLTS TOTAL DATE AMPERES AMPS. X VOLTS TOTAL LEG 1 LEG 2 LEG 1 LEG 2 KVA LEG 1 LEG 2 LEG 1 LEG 2 KVA Figure 3. 14 W.D..A.G.O. FORM NO. 5-90 WORK SHEET FOR UNDERGROUND DISTRIBUTION AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See T.MS-681 DATE MANHOLE OR VAULT (Location or No.) I NSP ECTOR LEGEND FOR MARKING SATI SFACTORY X - adjustment NEEDED XX- REP Al RS OR REPLACEMENT 0 - DEFECT CORRECTED SYMBOLS INSPECT AND CORRECT 2 3 4 5 6 5 YEARS 5 YEARS YEAR “ MONTH UNDERGROUND SYSTEM MANHOLES VENTILATING when fumes are present CLEAN ROOFS, WALLS, FLOOR duct SEWER AND SUMPS CABLE racks ’ coy ER CABLES — 8 9 10 11 12 12 EL ECTROLYSIS GROUND WIRE CONNECTIONS CABLE SHEATH BOND CRACKS, BREAKS AND PUNCTURES CABLE RACKS AND INSULATORS CABL E TEMP ERATURE JUNCTION BOXES - CABLE GASKET BREAKS ANO LEAKS 14 15 16 17 COVER BOLTS YEAR MONTH LINK CONNECTIONS Al R PRESSURE REMARKS AND RECOMMENDATIONS 18 19 20 21 CL E AN CRACKED PORCEL AIN L E AK AG E TERMINALS TRANSFORMER VAULTS — 22 23 24 25 26 27 28 22_ CL EAN ROOF, WALLS, FLOOR INSULATORS, CUTOUTS S BUS BARS GROUND CONNECTIONS VENTILATION LOCK AND COO R 1 OENTI Fl CAT ION FIISF EQUIPMENT TRANSFORMERS 30 31 32 33 LOAD TEST (No change in loading) LOAD TEST (Load changes) LEAKAGE OF OIL OIL TEST 1 — DISPOSITION OF WORK SHEET THIS WORK SHEET SHOULD BE HELD IN THE POST ELECTRICAL MAINTENANCE FILE UNTIL REPAIRS ARE COMPLETED AND INFOR. MATION RECORDED ON MAINTENANCE SCHEDULE M.D. .A.G.O. FORM NO.5-91 AND ALL TEST DATA PROPERLY RECORDED. IT MAY THEN BE DESTROYED. Figure 4. 15 5 Years Year Month 2 3 4 5 6 7 1 UNDERGROUND-SYSTEM MANHOLES Prepare maintenance schedules so manhole inspections are made at the same time as cable inspections. Caution: Inspector must always be accompanied by a qualified electrician when inspecting manholes. Ventilating when fumes are present. Before entering manhole, make sure it is free from dangerous gases. If presence of inflammable or obnoxious gas is detected or suspected, ventilate manhole thoroughly with a power or hand blower placed on windward side of manhole opening. Blowers should be equipped with a canvas tube long enough to reach within 18 inches of bottom of manhole. Determine source of gas and take necessary steps to eliminate it. Provide some means of ventilating manholes located near gasoline storage tanks or fueling stations. To assist natural ventilation when men are working in a manhole, hang a canvas curtain from top of manhole guard to about 18 inches above manhole floor, and turn curtain broadside to wind. Never .take lighted cigarettes or other open flames into a manhole until certain manhole does not contain explosive gases. Sparks from tools striking against metal or stone may also set off an explosion if explosive gas mixture is present. Clean. Remove dirt and all superfluous material found in manhole. Roof, walls, floor. Examine manhole roof, walls, floor, and duct entrances for cracks or other defects, and make all necessary repairs. Apply asphalt paint to rusted iron beams, cable racks, manhole frames, and equipment in manhole. If a ladder is permanently installed, inspect it carefully for weakness due to rusting or corrosion. If base of ladder is under water, remove water so entire ladder can be inspected. Coat rusted portions with asphalt paint. Duct. Inspect duct shields. Note whether cable is free to expand or contract and if it is being damaged by abrasion at duct entrances. Replace defective or rusted shields. Sewer and sumps. Keep drainage system open; clean out sumps that are filled with dirt and clear plugged sewer connections. Cable racks. Check for loose anchor bolts, missing cable racks, broken or missing rack insulators, and defective or missing cable saddles. Examine supports for severe rusting or corrosion. Make sure supports are adequate and that cable is not riding too near the edge and is not sagging between supports. Replace defective or missing items. Cover. See that manhole cover is not cracked or broken and that it seats properly in the frame. Clean out plugged vent holes. Where double covers or gasketed inner covers are used, inspect gaskets and replace them if necessary. CABLES Prepare maintenance schedule so cables in a draw-in*type system are inspected in late summer months, when load plus summer heat is most likely to show up flaws such as leaks, hot spots, movement of cables, etc. However, if load is considerably heavier at some other time of the year, schedule inspection at that time. 16 5 Years_____Year Month 8 9 10 11 12 Electrolysis. If direct current is used in the vicinity, test lead-covered cables for signs of electrolysis. Measure voltage difference between cable sheath and earth, water pipes, gas pipes, and all other submerged metal structures, taking readings at manholes, vaults, or other locations where cable is readily accessible. (See fig. 5.) For best results, make these measurements with a high-resistance voltmeter having zero at center of scale. Cable sheath should be negative to earth and other underground structures to prevent damage from electrolysis. If voltage reading is greater than plus or minus ^4 volt, consult the serving utility for proper action to minimize effect of electrolysis or cathodic action. Ground-wire connections. Inspect ground wire for corroded and loose connections. Replace if not tight and in good condition. Cable-sheath bond. Make sure bonding wire extends at right angles to lead cable sheath and does not touch cable sheath at any point other than point of attachment, where it should be completely covered with solder. Check bond contact for looseness or corrosion. Good bonding contact is essential. Observe temperature. Cracks, breaks, and punctures. Inspect entire length of cable in manhole for punctures, cracks, breaks, or leaks in lead sheath. Look for hairline cracks at bends in cable. Be particularly careful in checking at duct mouths, where most cable defects occur. Make sure there are at least 3 inches of straight cable coming out of duct. Cable which is bent at duct edge may become excessively worn by rubbing against duct during expansion and contraction caused by load changes. Check for duct shields which have fallen out or are out of line, rusted, or corroded. Refasten shields to cable in proper position or replace if necessary. Inspect joints carefully for cracks, bulges, checks near ends, leaking compound, or any signs of deterioration. If cable is partially or completely submerged, examine sheath for signs of corrosion or electrolysis, which is most likely to take place at the waterline. Corroded bond wires or cable supports are signs of electrolysis. If water drains into manhole through cinders or decayed vegetable matter, it may have a fairly high acid or alkaline content and may damage cables. Check solder seals and wipes for corrosion, since they may be affected even when cable sheath is not. Cable racks and insulators. Check cable racks and insulators to insure that cables and joints are properly supported at all times. Make sure cables or joints are not pressing against manhole wall or so far from wall that they are liable to fall .off supports. Note any unusual cable movement. Cables may be pulled off supports by contraction and expansion due to temperature and load changes. Cables may tend to creep in one direction as result of difference in elevation of supports. Cables may move more at one end of manhole than at the other, causing excessive bending in cables or straining at joints. Cable temperature. For rough check on cable temperature, feel entire length of cable sheath in manhole. If bare hand cannot be held comfortably on sheath, outside temperature of cable is over 55° C. (131° F.) and conductor temperature is over 80° C., or over maximum rated temperature for copper in most cables. Any marked difference in temperature in same cable length indicates that local hot spot is developing. Report overheated cables and hot spots immediately. 13 17 STRUCTURE s V A' '71 *____________ V «; \ jl sS- MULTIPLE-SCALE HIGH-RESISTANCE DC VOLTMETER _Q____________O 'Illi-----------J j CONNECT TO CONNECT TO HYDRANT, / ><~CABLE SHEATH EARTH, WATER PIPE, OR' OTHER SUBMERGED METAL CABLE MANHOLE Figure 5. Using high-resistance voltmeter to test for electrolysis. JUNCTION BOXES—CABLE 5 Years Year Month 14 Junction boxes are the sealed, waterproof-type boxes used for lead-covered cable branch circuits, with link connections for isolating various sections of the circuit. Gasket breaks and leaks. Inspect cover gasket visually for breaks or leakage. 15 Cover bolts. Check cover for loose, broken, or missing clamp bolts. 16 Link connections. Whenever junction box is open, check the links and clips for loose connections. 17 Air pressure. If junction box operates with internal air pressure, make sure a minimum internal pressure of 15 pounds is maintained. POTHEADS Caution: Deenergize circuit if possible. If necessary to work hot, use of rubber equipment is mandatory on voltages of 5,000 or less. On voltages above 5,000 use hot-line tools. 18 19 20 21 Clean. Clean potheads thoroughly. Increase frequency of cleaning in corrosive or dusty atmosphere. Cracked porcelain. Inspect for cracked or broken porcelain and report defects noted. Leakage. Examine for signs of leaking compound, especially on potheads mechanically connected to cable sheath. Repair if leakage is found. Terminals. Open and clean terminals on disconnecting-type potheads. Check for overheating, a sign of poor contact. Increase frequency of inspection if equipment is exposed to corrosive gases. 18 5 Years Year Month 22 23 24 25 26 27 28 29 TRANSFORMER VAULTS Caution: Use of rubber gloves or hot-line tools is mandatory. All energized wires, buses, etc., in reach of personnel must be protected or effectively roped off. Schedule vault inspections for same time as cable inspection is performed. Before inspecting any vault, check for presence of dangerous gases, paying particular attention to vaults near gasoline storage tanks. If gas is found, take necessary steps to eliminate it. Never take lighted cigarettes or open flames into a vault until certain that it is free from explosive gases. Clean. Clean vaults, ventilating grates, and air ducts. Increase frequency of cleaning air ducts if atmospheric conditions make it necessary. Do not store unnecessary materials in vaults. Roof, walls, floor. Check vault for structural defects in roof, walls, or floor. If there are signs of moisture seeping into vault, make necessary repairs to correct this condition. Generally, excessive amounts of water in vault indicate need for sewer repairs. If vault is equipped with a sump pump, operate it by hand to test its performance. Check pump motor in accordance with instructions in section III. Insulators, cutouts, and bus bars. Inspect for cracked or defective insulators and bushings. Remove dust from insulators, cutouts, bus bars, transformers, fuses, and other equipment in vault by wiping with a cloth or feather duster. Do not clean equipment operating at over 5,000 volts while it is energized. When cleaning energized equipment operating at less than 5,000 volts, always wear rubber gloves; nearby equipment must be separated or protected with rubber covering to prevent accidental contact with an energized conductor. Ground connections. Check resistance of ground connections on cable, transformer cases, and other grounded equipment. Resistance should not exceed 25 ohms. Ventilation. Report high air temperature within vault and provide additional ventilation. Insure good air circulation around transformers carrying rated load or higher. Lock and door. Make sure door lock is in good operating condition and keys are available to proper personnel. If vault door does not swing freely, repair it immediately. Paint rusted spots on doors and other metal fixtures in vault. Identification. See that identification and warning signs are properly placed outside vault door. Fuse equipment. Inspect cutouts for cracked or damaged housings and hangers. Check condition of fuse holders and line and load contacts. Clean, adjust, and lubricate contacts to prevent corrosion and overheating, which cause outages and damage to equipment. TRANSFORMERS Caution: Use of rubber gloves or hot-line tools is mandatory. All energized wires, buses, etc., in reach of personnel must be protected or effectively roped off. Maximum load on subway transformers depends on their ability to dissipate heat losses. Ordinarily, they may be loaded to 125 percent of name-plate 19 5 Years Year Month 30 31 32 33 rating if load is continuous for no more than 2 hours, with at least a 1-hour cooling period before transformer is loaded again. If load is to be continuous for 4 hours, do not exceed name-plate rating. For further information see TM 5-680. Check temperature of transformers and cutouts periodically by touch, first making certain transformer and cutout cases are grounded. If they feel too warm, notify the post engineer so load tests can be made. High temperature may also be due to inadequate ventilation. Cutouts may overheat because of poor contact of the fuse link, so the fuse link should be removed and contacts inspected. Oil level should also be checked. Note. Before connecting additional load to a transformer, refer to record cards and tests to make sure capacity is available. Load test. Make load test on transformers which supply a steady connected load. Install Max-I-Meters or equivalent for at least 24 hours at season of greatest load. Tests may also be made during loading period by spot-checking with split-coil ammeter, GE type AK-1 voltammeter or equivalent. If there are not enough meters available, borrow from serving utility. Enter test results on work sheet under “Remarks,” and report data to electrical supervisor for entry on transformer record cards. Load test. Make load test on transformers which supply a building or vicinity where the load is known to be increasing. Transformers supplying technical facilities should be load tested more frequently than once a year. For procedure, see item 30. Leakage of oil. Check tank for leaking seams, drain plugs, and valves, and for leads siphoning oil. If leaks are found, remove transformers from service and make necessary repairs. Oil tests. When a transformer which has been in service 6 years or more is disconnected from line and returned to shop for any reason, give it an oil test. Do not give oil test to transformer connected to the line. 7. Overhead Distribution Systems The electrical-facility maintenance program includes periodic inspections of government-owned transmission and distribution lines, with additional inspections after each outage. Inspections cover all wires, poles, transformers, and auxiliary equipment. Periodic system load tests and load-balance tests are necessary to show whether distribution circuits are properly balanced. Unbalanced loads cause excessive line losses and low voltage throughout the system. Complete records are kept of power failures and their causes to help reveal weak points in the system and show where maintenance is most needed. Thus, fuses blowing frequently during storms may indicate inadequate lightning-arrester protection, poor grounds, improper connection of arresters, or faulty transformer bushings. Repeated circuit outages during storms may indicate inadequate wire spacings, cracked insulators, excessive sag, or tree interference. Caution: Perform live-line maintenance on high-voltage lines only if the lines cannot be taken out of service for necessary maintenance. a. Distribution and block maps. (1) Prepation. To assist inspectors in their work, each post prepares block maps and distribution system maps or field-checks existing maps to bring them up-to-date. A procedure is also set up to help keep maps current by providing for monthly postings of all extensions, alterations, deletions, and other changes. For standard symbols used in the maps, see figure 6. For typical electrical distribution and block maps, see figures 7 and 8. Existing maps need not be revised merely to conform to these symbols and illustrations; however, for purposes of standardization, new maps should conform to the examples shown. (2) Use. The maps provide a basis for checking work progress and insuring complete coverage of the overhead distribution system. Inspectors check off the map, pole by pole, as 20 they proceed with their work. When their inspection is complete, they turn in the maps to the electrical supervisor. b. Transformer record card. Record cards are kept on all transformers in the overhead distribution system, just as for those in the underground system. (See par. 6a.) c. Inspection and maintenance instruction. The inspection schedule for an overhead distribution system provides for two types of inspections, one from the ground and one from the pole top. The former is a walking tour of the system to inspect equipment visually from the ground; use of field glasses increases the effectiveness of this check. Pole-top inspection involves climbing the poles for closer examination of equipment. Steps in these inspections are outlined on WD Form 5-85 (Work Sheet for overhead distribution and preventive maintenance services (fig. 9),) and discussed further in the instructions below. For instructions on using the work sheet, see paragraph 3a. Caution: On climbing inspections the usual safety procedure when in the vicinity of high voltage wires must be followed. See safety section, TM 5-680. 21 SUBSTATION OR SWITCHING & METERING POINT POLE - SIZE & CLASS POLE WITH DOWN GUY (ANCHOR) POLE WITH HEAD GUY POLE WITH STREET LIGHT SINGLE-PHASE TRANS-NO 17, 25 KVA, ON PHASE CN 3-PHASE TRANS-NO 15, 25 KVA NO 16,5KVA 3-PHASE TRANS BANK NO 17,10KVA NO 18,5KVA CONSTANT-CURRENT TRANS-NO 14, 10 KW, ON PHASE AN TRANSMISSION - NUMBER, SIZE,& VOLTAGE PRIMARY-NUMBER, SIZE, & VOLTAGE SINGLE-PHASE SECONDARY 3-PHASE SECONDARY SERIES STREET LIGHTING - NUMBER & SIZE MULTIPLE STREET LIGHTING - NUMBER & SIZE OIL CIRCUIT BREAKER-SIZE & RATING POLE-TOP SWITCH PRIMARY FUSE-CUTOUTS (NOTE IF RECLOSING TYPE) FUSED DISCONNECTS—SIZE SOLID DISCONNECTS JUMPER POINT CLOSED CONDUCTOR OPEN HOT-LINE TAPS CONDUCTOR-PHASE DESIGNATION NEUTRAL OR GROUNDED CONDUCTOR LOAD-PHASE DESIGNATION FOR 3 (f) - 4-WIRE SYSTEMS LOAD-PHASE DESIGNATION FOR 3 $ - DELTA SYSTEMS TRANSFORMER VAULT MANHOLE HANDHOLE BURIED CABLE UNDERGROUND CONDUIT SHOWING DUCT SECTION AND OCCUPIED DUCTS *Use serving utility's designation when possible. LEGEND FOR ELECTRICAL DISTRIBUTION SYSTEM MAPS AND BLOCK MAPS Figure 6. Q 40/5 a* (2) 17-25 CN ® ,5-“ ® 16-5 A 17-10B 18-5C j/J 14“10 AN ' 3-1/0 13,000 V 4-#6 2400/4.160 V 3-#4/0 ■H BBEMEEBB « BKK KI ESI OS 3-#2 OR 4-#2 l-#8 STEEL 2-#6 I J a— Focb I 400A X 1^*1 7,50QV-3_ ---aw* T ^’frrv'il1 • Tr-fiir- * >~f------------!t/ fi t ‘I / ta* n<|> 71J ■* 1 I if •’T/,f if k* i—। wo/4 -/zli! । I v ' L , <*F* 1 l'^" T/l । Il i| li । 'x § Ii Ii ^o/t । «. „ । I । i I. i<> 1 I----2-----40/4 & I I Ml4 hA^/2-7^ A I 1/ f $ I ■» L»/2 1 040^ 10^ 4/ It ®W/-t o___O®z-/2fl I l09-4‘^° \4O-7i B L"Ze-_2-/»-h* LI |0^Z<5-7% /W O Z9 S AH ,d W f I substation -~--fl s-/oc rt Lw 1 |l ■/J -5 c 2?_____° ====1 I I 1 l
t s L IKi r4 ? K- |!°- । 1* . I 1 , HIl [F- s-sc | I rT“—i------------------------------ $ । । ;| I I : s x § $ pj 1 * // 11 110-*0/* ^4°/z SiJ^ ’ 1 / Il I S' Z2-5 BN -<&/6-/O A । (T)l0wZ/ 'IC Jlw Ij !!?'-- iJP’w 1 i “I j> 11 $ s I^|! N/S" iv 7 * Ip $ J^L/. / —K— ‘ । fe_* — LZ^' —1'L Z—A1 , ----r—------------------- 56/z j$-=- -©— — —O- —far — ~'G~ ■ '■"■ &■ — ~ -@— — ---Q vj_4~ 1 ■' ■ —fil36!z ocalc J naXbc r-zoo' A oe Mope ?! "VI3KHS ARMY SERVICE FORCES -NOTES- >1$ | |- L SEE F/G 6 EOR LEGEND. --Q. 4»f>UG (b >9-10 AN ---- £. THIS PLAN TO BE DRAWN ON CAMP PLOT PLAN. X— ----------------------------------TYPICAL GENERAL-UTILITY MAP 3. S NON CONDUCTOR MATERIAL / TYPE OF ALL CONDUCTORS RY NOTE st-/SC -ELECTRICAL DMTR/BUT/ON SYSTEM 4. ALL LINES SNOWING ELECTRICAL CIRCUITS SHOULD ZZZZ FOR 4'W/RE Y SYSTEM BE HEAVIER THAN BUILDING OR STREET OUTLINES. ____ S. INDICATE STREET-LAMP WATTAGE OR LUMENS BY NOTE. --- -- Figure 7. 23 J £ ||^____________SECTION IZ j £ r,Wr f_______."Z------------1.________!H*. ___________V_________5r ..— A—** -A---------------=».----------- -*.--------— ZE — --------------------- 1 psZrss/4 ------- I -------------- ---------- । -------------- ---------- m ______________ -------I । ------------- ----------|x ji ----------------------L . [____________ -------iP J‘L*//i------- ---------- ---------------- ----------1 'r~____________ z i££ r'G 6 rol? legend. 7-----------------------\ y-------------------------JI/ 2. ALL LINES SHOWING ELECTRICAL CIRCUITS SHOULD (f/-*57^ ^3\ | (t BE HEAVIER TRAN BUILDING OR STREET OUTLINES. -------I" Ti/ ---------- ----------------7 P#l------ -------TW--------------- J. INDICATE STREET LAMP WATTAGE OR LUMENS BP NOTE. li2'*--------------------I---------------------------?--------------------------4. SHOW CONOOCTON-MAYER/ALI PEPE OP ALL ———11 ! -------- ---------- ---------------- ---------- P ------- CONDUCTORS RY NOTE. -I I 5E(T/0/V£0 A -| p 2 ---------J --------------- ----------i \ ------ I P "j 3»4x^l® ^saN /<3|0 MSN y^n-focri P ------ ---------- । h * ii> • I _--------------------A Mi I _______ k \L48______ __________ | |N ___________ __________ |^fl____________ -p 0^4^__________________—1*^________________________'"'■*•45^ _______Il \ ____________ __________ / | vri--------- ------- S' \l---------- !? V-9______sy--------------------------& I C---------------------- ___________________________ -------JN ------- ----------\y '------- ----------v -------- SCA,-C । ' I _2^_ ney,sio»s ARMY SERVICE FORCES ------- < -------- ---------- * I ------------ y 1 HE , , a ^/x-----------------------------A .< ----TYPICAL SECTION OR BLOCH MAP __________) _____________________J _____________________J -------- ------------ELECTRICAL DISTRIBUTION SYSTEM I __ ---- FOR 4-YV/RE Y SYSTEAA SECOND SECTION 28 | | 5T ZZZZ Figure 8. 24 !o^’I!oG;-85 work sheet for overhead distribution Nov/ 1944 AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See T M5-631 for detailed Instructions and Procedure POLE LOCATION OR NO. DATE INSPECTOR LEGEND FOR MARKING SYMBOLS „ / V- ADJUSTMENT X/-SAT 1 S FACTO RY X NEEDED yy- REPAI RS OR REPLACEMENT O - DEFECT CORRECTED 1 (-INSPECT ANO 1 1 CORRECT T t A K STRUCTURES 51 2 YEARS r 1 r [~ YEAR V ARMS. PINS 4 ‘ YEAR ▼ GUYS 4 ANCHORS 1 1 1 2 VISUAL FROM GROUND (Sp1its,twist-ed.decay, defective pins) 1 1 11 CORROSION (Broken strands, creep, loose connections, broken, missing 4 clearances) 1 'KHSv;' 1 CLIMBING INSPECTIO twi sts,decay, def N (Splits. active pins) 1NSULATDRS ARRESTERS 12 13 VISUAL FROM GROUND (Cracked, broken. missing) CLIMBING INSPECTION ( Cracked, broken, missing - clean if requi red) 1 1 3 4 VISUAL FROM GROUND (Shattered, cracked, missing, ground continuity and mounting brackets) 1 CLIMBING 1 NSP ECTIO or ground connect (Loose line LINE WIRES ions, bolts, — ~ -a. f - J — 14 15 16 TWISTED, SLACK, TAUT 0R CROSSED CLEARANCES BETWEEN CONDUCTORS, ABOVE WALKS, STREETS, RAILROADS, AND COMMUNI CATION LINES ADEQUATE CLIMBING SPACE corrosive mounting, clean if necessary) BOLTS & BRACES | | 5 CLIMBING INSPECTION (Rusted bolts and nuts. Missing braces) POLES. WOOD 17 18 18 19 19 UNTREATED (Decay, shell & heart rot. buckling, leaning & split) BUTT TREATED (Split buckling, leaning) BUTT TREATED (Sound for heart.rot probe at ground for decay) FULLY CREOSOTED (Split, buckling, leaning) FULLY CREOSOTED (Sound for heartrot, probe at ground line for decay) RUILDIHfi SERVICES 1 1 6 INSULATORS, DRIP LOOPS (Defective insulators, drip loop, condulet) □ CUTOUTS 7 8 VISUAL FROM GROUND (General condition, connect ions , housingf. clean if required) CLIMBING INSPECTION (Cracked or damaged housing, hangers, fuse holders & contacts - clean if required) □ TRANSFORMERS, DISTRIBUTION 20 21 LOAD TEST (No change in loading) LOAD TEST (Load change) CONNECTIONS 4 BUSHINGS OIL LEAKAGE OIL TEST 22 23 24 FUSED AND UNFUSED DISCONNECTS 9 CLIMBING INSPECTION (Contacts, insulators, mechanism, - clean 4 grease if necessary) TREE TRIMMING I_J25 TRIM TREES GROUNDS VOLTAGE TESTS 10 RESISTANCE (Test, check connec. t ions to ail equipment, mould, ing protection) 26 27 PRIMARY Cl RCUI TS END OF SECONDARY REMARKS AND RECOMMENDATIONS DISPOSITION OF WORK SHEET THIS WORK SHEET SHOULD BE HELD IN POST ELECTRICAL MAINTENANCE FILE UNTIL REPAIRS ARE COMPLETED AND INFORMATION RECORDED ON MAINTENANCE SCHEDULE. W.D. .Vf.A.G.O.. FORM NO.9-SI AND ALL TEST DATA PROPERLY RECORDED. IT MAY THEN BE DESTROYED. Figure 9. 25 tars Years Year ARMS, PINS, AND STRUCTURES 1 Visual from ground. Check general condition of arms, pins, and wood structures; note defects such as splits, twisting, decay, and defective pins. 2 Climbing inspection. Check for decayed and split cross-arms or timbers, par- ticularly around pins. Determine extent of decay by prodding around pins with screw driver. Replace arm when decay or splits cause loose pins or seriously reduce strength. Replace twisted arms, usually a result of unbalanced strains on dead end points, with a properly guyed new arm. Check for damaged pins causing loose insulators, usually a result of insulator leakage. Replace if damaged. Examine wood structures for all weakening defects, decay, and the like and report necessary repairs, ARRESTERS 3 Visual from ground. Check for shattered, cracked, or missing mounting bracket. Check continuity of ground connection. 4 Climbing inspection. Inspect for loose line and ground connections; make sure all connections are tight and make good electrical contact. Check mounting bracket for corrosion, loose bolts, and breaks. Inspect porcelain housing for cracks and broken porcelain. To prevent external flashovers, maintain required clearances to grounded hardware and line conductors. In contaminated atmospheres, clean exposed insulation surfaces periodically. Inspect more frequently if located in a heavy storm area. Before handling arresters connected to circuits above 5,000 volts, disconnect them from line. Caution: Line must be deenergized before high-voltage arresters (above 5,000 volts) are connected to line conductor. BOLTS AND BRACES 5 Climbing inspection. Replace immediately braces and bolts which are miss- ing, broken, or so rusted they will not safely support attached equipment. BUILDING SERVICES 6 Insulators, drip loops. Replace defective insulators immediately. Install drip loops in wires at service entrance to buildings to prevent water from following wire into building and causing outage or fire hazard. Provide service wire with proper clearance from roads, walks, and other buildings. Check entrance condulet for missing cover or other defects, CUTOUTS 7 Visual from ground. Note general condition of connections, housing, and supports. Remove straw and other debris carried by birds. 8 Climbing inspection. Check for cracked or damaged housings and hangers and for condition of fuse holders. Inspect for loose and corroded line and load contacts, which may cause outages and damage to equipment. To facilitate operating cutouts which are attached to arm with adjustable hanger, turn cutouts toward pole to make a 60° angle with arm. Clean and adjust contacts and lubricate to prevent corrosion. To prevent flashover, clean porcelain insulation on cutouts as often as needed to remove conductive coating which tends to form. Cleaning is not often necessary on circuits under 5,000 volts. 26 yL Year FUSED AND UNFUSED DISCONNECTS 9 Climbing inspection. Check contacts, insulators, mountings, and adjustment of mechanism which operates rod and interphase shafts. See that contact surfaces are clean and bright. Whenever a switch is open for any reason, inspect contacts, clean if necessary, and protect them with coating of nonoxide grease. GROUNDS 10 Resistance. Test enough grounds to make certain satisfactory grounding condition exists in all vicinities. Resistance of a ground should not exceed 3 ohms for water-pipe connections or 25 ohms for artificial grounds. Ordinarily, resistance of grounds connected to water pipes need not be measured. Examine connection to pipe to be sure it is making good electrical contact. If resistance of artificial ground is 25 ohms or more, drive at least one additional ground rod; space ground rods not less than 6 feet apart. If additional ground rods do not reduce resistance below 25 ohms, the post engineer should ask assistance of the serving utility and/or the service command. Check ground connections to transformer cases, secondary neutral wires, lightning arresters, and ground rods. See that ground wire is rigidly supported, not cut, and that cross section is not accidentally reduced to any great extent. Make sure ground wire is covered with ground molding to at least 10 feet above pole base. Where ground wire passes other wires on pole, cover ground wire for at least 6 feet below and 4 feet above the wires. GUYS AND ANCHORS 11 Corrosion. Check guys for corrosion, broken strands, creeping of anchors, loose connections, and clearance to live conductors. Report defective, broken, or missing guys for replacement. INSULATORS 12 Visual from ground. Check for broken, cracked, or missing insulators and replace if necessary. Use field glasses if available. Caution: Use of protective equipment or hot-line tools is mandatory. If insulators must be cleaned, and circuit cannot be deenergized, a carefully coordinated safety procedure must be followed. 13 C liming inspection. Check for cracked or broken insulators; if any are found, replace immediately to prevent outages, loss of current, and damage to equipment. Clean insulators periodically with a solvent such as ammonia, carbon tetrachloride, or soapy water to remove dirt deposits which under moist conditions may cause flashover. After cleaning with solvents, wash with neutralizing solution of sodium bicarbonate. Insulators on circuits under 5,000 volts need not be cleaned often. More frequent cleaning is necessary if voltage is higher or if installation is near coastal waters or localities with dirty atmosphere. Use the system recommended by the serving utility when washing insulators on high voltage lines. LINE WIRES 14 Twisted, slack, taut, or crossed. Note tension in line wires and report off-standard conditions. Adjust immediately wires which are too slack or too tight. Clear any crossed wires and make necessary changes to prevent recurrence. 27 5 Years 2 Years__Year 15 Clearances. Check to see that all clearances are correct. For approved clearances between conductors and above guys, walks, streets, highways, railroads, and communication lines, see TM 5-680 or National Electrical Safety Code. 16 Climbing space. Check for adequate climbing space on all poles and clear any dangerous conditions noted. For standards see TM 5-680 or National Electrical Safety Code. POLES, WOOD To reduce fire hazard, remove tall grass, weeds, and inflammable material within 4 feet of base of pole. To provide drainage, earth should be rounded about base of pole to a height of approximately 6 inches. If pole is to be tested for rot, determine amount of decay at ground line by digging out around pole to a depth of 1 foot. Support rotted poles with pike poles or guys until they can be permanently braced or removed. 17 Untreated. Inspect untreated poles for decay at ground line, shell or heart rot, splitting, damage by lightning, leaning or buckling due to overload or strain. Report any defects for immediate repair. 18 Butt-treated. Inspect butt-treated cedar poles for splitting, damage by lightning, and leaning or buckling due to overload or strain. 18 Test butt-treated cedar poles for heart rot by sounding above ground line; test further by drilling into pole below ground line after pole has been set for 15 years. Repeat drilling test every 5 years thereafter. 19 Fully creosoted. Inspect full-length-creosoted southern-pine poles for splitting, damage due to lightning, and leaning or buckling due to overload or strain. 19 Test for heart rot by sounding only; do not bore test holes in these poles. After pole has been set for 15 years, test for shell rot by probing at or below ground line; repeat test every 5 years thereafter. Use a probing rod, taking care not to damage pole. TRANSFORMERS DISTRIBUTION Caution: Usfe of rubber gloves or hot-line tools is mandatory. All energized wires in reach of personnel must be protected. Ordinarily, overhead distribution transformers may be loaded to 150 percent of name-plate rating if load is continuous for no more than 2 hours, with at least a 1-hour cooling period before transformer is loaded again. If load is to be continuous for 4 hours, do not exceed 125 percent of name-plate rating. For further information see TM 5-680, Note. Before connecting additional load to a transformer, refer to record cards or tests to make sure capacity is available. 20 Load test. See item 30, paragraph 6. 21 Load test. See item 31, paragraph 6. 22 Connections and bushings. Correct loose and corroded transformer and bus connections immediately to prevent heating, faulty service to attached equipment, or outage. Inspect bushings and leads and clean periodically to avoid flashover due to dirt. 28 23 24 26 27 Leakage of oil. See item 32, paragraph 6. Oil test. When a transformer which has been in service for 6 years or more is disconnected from line to replace arm or pole or to change transformer size, give it an oil test. Do not give oil test to transformers connected to the line. TREE TRIMMING Trim trees. Trees near overhead lines are a potential source of trouble because they may break and blow across wires during a storm. The limbs may break wires or cause a short circuit. To avoid this type power interruption, establish a regular program of tree trimming. For limbs under 3 inches in diameter, allow at least 8 feet of overhang clearance, at least 4 feet of side clearance, and at least 3 feet of underneath clearance. Maintain a climbing space 40 inches square through trees on climbing side of pole. Do heavy pruning and heading back of old trees in late fall or during winter when trees are dormant. Trim new growth soon after spring growing period. VOLTAGE TESTS Primary circuits. Test primary-line voltage on each circuit at distribution transformer nearest substation, at middle of circuit, and at end of circuit. Repeat test whenever considerable load has been added to circuit. If voltage is higher than standard or more than 5 percent below standard, determine the cause and take necessary corrective steps. End of secondary. Determine voltage at end of secondary lines by testing for 24-hour period, using a recording voltmeter, if available. If possible, make test at location having greatest line drop. Make additional check whenever considerable load is added to a building. Do not move transformers, increase size of secondaries, or install additional transformers to correct a voltage drop of less than 5 percent, unless voltage is critical for proper operation, as with link trainers, teletype machines, X-ray machines, etc. 8. Street-lighting Systems Street-lighting and auxiliary equipment is normally inspected during regular inspections of the post electrical-distribution system. However, the preventive maintenance procedure below is set up to insure that this part of the system is not overlooked and to provide for regular lamp-bulb replacement. It may be practical for the inspector covering the overheaddistribution system to carry along the work sheet for street lighting and include both inspections on the same trip; however, lamp-out-age patrol and group-lamp replacement (items 7, 8, and 9 below) must be performed on separate trips. a. Transformer record card. Performance records of each constant-current transformer is kept on a transformer record card. (See par. 6a.) b. Maps. Electrical distribution maps (par. 7a) are used by inspectors to check off their progress, lamp by lamp, as they make their inspection. Maps are turned in to the electrical supervisor as soon as the inspection is completed. c. Inspection and maintenance instructions. Steps in maintenance of street-lighting systems are outlined on WD AGO Form 5-86 (Work sheet for street lighting and preventive maintenance services (fig. 10)). Instructions below supplement the work sheet, giving detailed procedures for each step. For instructions on using the work sheet, see paragraph 3a. 29 DISPOSITION OF WORK SHEET THIS CHECK SHEET SHOULD BE HELD IN THE POST MAINTENANCE ELECTRICAL FILE UNTIL REPAIRS ARE COMPLETED 4 INFORMATION RECORDED ON MAINTENANCE SCHEDULE W. D. .A.Q.O. FORM NO.5-91 & ALL TEST DATA PROPERLY RE. CORDED. IT MAY THEN BE DESTROYED. Figure 10. 1,1 ................ ' " 1 Ml.. ro?M’Io%°-86 WORK SHEET FOR STREET LIGHTING October 1941 AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See T MS-681 for Detailed Instruction and Procedure POLE OR LAMPPOST LOCATION (DATE I I NSP ECTO R • LEGEND FOR MARKING SYMBOLS /— SATISFACTORY X~ A0JUSTMENT XX- REPAIR OR 0- DEFECT I 1 INSPECT AND x/ norsuiuKT REQUIRED REPLACEMENT CORRECTED 1-----1 CORRECT ------------- 5 YEARS --------------------------------------------------2 YEARS -------------- 1 YEAR ------------------------------------------------- MO N T H |------------------------------------------------ WEEK r---------------- 20 00 HOURS ▼ ▼ ▼ ▼ ▼ ▼ CONSTANT CURRENT TRANSFORMERS________________________________________________________________________________ |1 I I II I I___________11 II II 111 I ampere test CONTROL EQUIPMENT_______________________________ 2 | | j OIL SWI TCH connections, oil leaks, broken bushings,corroded 2 [| o OIL SWITCH (Renew oil,clean tank,check operating parts A contacts. t -----1 I---—I a Clean bushings,check interior wiring;renew gasket if > || 3 TIME GLOCK (Check and reset) necessary) 3 I I 3 TIME CLOCK (Check contacts and grease with non-oxide grease) 3 | | 3 TIME CLOCK (Clean and overhaul) 4 | | < PHOTO CELL CONTROL .___________________FIXTURES AND MOUNTING BRACKETS____________________ 51 n | i ] n n 5 LAMPS ON POLE BRACKETS (Loose bolts A wiring. Levil installation, broken ref1ectors ar glassware) 5 | | 6 LAMP STANDARDS (Check connections, insulating transformer, corrosion, defective insulation. Clean out dust and dirt and check painting) LA*?5_________________________________ 7 | | 7 PATROL (Check for broken or burned out lamps) 8 r~H 8 GR0UP REPLACEMENT OF SERIES LAMPS 9 9 REPLACEMENT MULTIPLE LAMPS REMARKS AND RECOMMENDATIONS 30 5 2 2,000 Years Years Year Month Week Hours 3 3 3 4 CONSTANT-CURRENT TRANSFORMERS Lightning arresters, cutouts, and transformers are to be checked with other line equipment as described in paragraph 7. Ampere test. Check current in secondary circuit of constantcurrent transformer supplying a series lighting circuit. Adjust if necessary to obtain a current of not more than 6.60 amperes and not less than 6.56 amperes for 6.6-ampere lamps. Reduce number of lamps by at least 25 percent and note whether transformer adjusts itself to the proper current. 2 2 CONTROL EQUIPMENT Usually, a manually operated oil switch, a time clock, or a photoelectric device turns series street lights on and off. Oil switch. Inspect oil switch for loose connections, oil leaks, broken bushings, corroded tank, etc. Renew oil and clean tank, checking all operating parts at same time. Examine contact surfaces and smooth them if necessary. Clean bushings. Check interior wiring for any defects. Renew cover gasket if necessary to provide a watertight closure. Time clock. If time clocks operate the contactor, check and reset clock; these clocks may lose or gain as much as 15 minutes a month. The average service life of a time clock is 5 years. Clean and overhaul all time clocks at 5-year intervals. Inspect contacts on low-voltage time switches, and grease with a nonoxide grease. Photo-cell control. Where street-lighting circuit is controlled by a photoelectric device, mount the electric eye to point north and up at a 221/2° angle above the horizontal. Clean window in electric eye. On a cloudless day and after windows have been cleaned, check output of electric eye with a milliammeter. Normal output is between and 6 milliamperes, but it may be as low as milliampere and still operate the relay. When output current is below milliampere, replace electric eye and send it to manufacturer for repair. Caution: Relay used with photo-cell is a delicate instrument and should be installed where it will be as free as possible from severe jar or vibration. Sticking contacts should be cleaned carefully, but other repairs should be made only by authorized, experienced personnel. FIXTURES AND MOUNTING BRACKETS 5 Lamps on pole brackets. Inspect lighting fixtures and mounting brackets for loose mounting bolts and wire connections, level installation, and broken reflectors and glassware. Schedule this inspection at same time as annual visual inspection of other overhead-line equipment. 31 5 2 2,000 Years Years Year Month Week Hours 6 8 9 Lamp standards. Open and inspect ornamental lamp standards. Check connections and insulating transformer. Note conditions of insulation on wiring. Remove debris and check for corrosion or bad insulation. Note and report condition of painting. LAMPS Patrol. Patrol weekly to check for broken or burned-out lamps. This patrol may be eliminated if other post personnel cooperate by reporting burned-out lamps to post engineer. Group replacement of series lamps. Divide the post’s series street-lighting system into groups of 40 to 50 lamps for group replacement. This is approximately 1 day’s work. Keep a record of casual burnouts in each group, and when 10 percent of group has been replaced because of burnouts replace and discard remaining lamps in group; clean glassware and reflectors at this time. Average burning life of standard 6.6-ampere series lamp is 2,000 hours. Use discarded lamps for replacement in fixtures close to electrical shop where correcting frequent outages will not require considerable transportation and time. On series lights having removable series socket, replace filmdisk cutout and replace lamp in series socket before inserting socket in fixture. Check drip loops and seals around wires as they enter the fixture or bracket. Note whether ventilation is satisfactory. Replacement, multiple lamps. Replace multiple streetlight lamps when burned out or blackened from long service. Do not use group-replacement system for multiple lamps. 9. Building Systems and Equipment Building wiring is subject to all sorts of tampering and must be checked frequently to reduce fire hazard, correct defective wiring, and eliminate oversized lamps and improper fusing. The schedule of inspections below is intended to assure good maintenance procedure and to prevent outages and fire losses. a. Building electrical inspector’s record CARD. WD AGO Form 5-84 (fig. 11), is used for a permanent -record of building-wiring inspections. Identification data at the top is filled in during the first inspection; spaces on the back are filled in when periodic inspections are made. Space is provided for a rough sketch of the building, showing authorized lamp sizes. These cards are kept in the electrical supervisor’s files when not in use by inspectors. 6. Inspection and maintenance procedures. (1) WD AGO Form 5-88 (Work sheet for building, wiring and preventive maintenance services) (fig. 12), helps the building inspector find defects in building-wiring systems and insures complete maintenance. For instructions on using the work sheet, see paragraph 3a. (2) Quarterly inspections shown on the work sheet are first echelon maintenance and are performed by the using service when ordered by the post commander. This plan results in more economical and satisfactory service. However, final responsibility rests on the electrical staff who inspect annually and report on the performance of first echelon inspections and maintenance services. The using service replaces defective incandescent lamps, getting new ones by exchange from the post engineer. The electrical staff replaces fluorescent lamps. (3) The using service uses the work sheet when making its inspection. After checking items for which it is responsible and performing necessary services, it sends the work sheet to the post engineer, who transfers information to the preventive maintenance schedule (par. 35) and prepares any necessary work orders. (4) Instructions below supplement the work sheet, giving detailed procedures for each inspection. 32 W.D. ,A G.O. ' FORM BUILDING ELECTRICAL INSPECTOR’S RECORD LOCATION (BUILDING TYP E VOLTAGE IphASE ImETER CONNECTED LOAD CRI Tl CAL LOAD TRANSFORMER TYPE CONSTRUCTION ° 111111111111111111111 |SI|E|T<|H|B|U|L|)l|NjS|HHl>|G[rpuTI*-H*uTl11111111111111111 HHzHz ---------------o_____o___o___-jT 6 ___ ® __ o.ZT • • ZjE * ZZZZZ jlLZ ZZTZ ------- -------;LO<>—ZOO2O)-------ioo 66 ___________________ __________________ zzz::zzzzzzzzzzzzzz _-------------™_ izzzz z EEEzAJJ-________WEEE:zzzzz" zzzz Z Zo. O . 7o ’==o«a<» n o I frOp--130-- ZOO- 203—-j ____________________________ |||| ____________:___ :zz:zzzzzzzzzzzz?zEi38S£zzzzzzzz:zz:zzzzzzzzzzzziz2^^E[:c£iczzzzzizzzzzziz :EE:EEEEEEEEEEEEE^i^ci3]2EriE^ri2EEEEbEiEs=EEA^2iEEEEEz=EE=EEEEzE==Ez _____________________________________AUTHORIZED LOAD_______________________________ LAMP S (MOTORS ICOOKI NG AND OTHER ROUTINE INSPECTION RECORD QUARTERLY QUARTERLY QUARTERLY YEARLY DATE INSP ECTOR DATE tNSP ECTOR DATE INSPECTOR DATE INSP ECTOR 5 YEARS DATE INSPECTOR Figure 11. 33 W. D. ,A. G.O. FORM NO. 5-83 NOVEMBER 1944’ WORK SHEET FOR BUILDING WIRING AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See T Ft 5"*68/ for detailed Instruction & Procedure BUILDING NUMBER AND LOCATION CATE INSPECTOR SATISFACTORY LEGEND FOR MARKING * ADJUSTMENT * REOU I RED REP Al R OR AA REPLACEMENT DEFECT 0 “ CORRECTED SYMBOLS I N SP ECT AN D ~ CORRECT 5 1 YEARS YEAR 3 MONTHS WIRING SYSTEMS 1 GENERAL CONDITION (Circuits, overload. National Code) 2 LOOSE WIRES AND CONNECTIONS (Loose or bare, poor connections, non-standard attachments, defective attachment cords, cords 3 LAMP SI ZES (Correct size) _ _ _ _ too loni. fire hn rds ) DISTRIBUTION PANEL 4 GENERAL (Clean, lock, circuit identification) 5 FUSES (Sizes, shorted out) 6 CONNECTIONS (Wires, lugs , switch contacts, fuses) 7 GROUNDS (Test for accidental grounds) 8 LOAD BALANCE ON CIRCUITS 1 1 9 GROUNDED NEUTRAL (Continuity, resistance of rod) LIGHTING FIXTURES 10 REFLECTORS AND LAMPS (Clean) 11 LAMPS INCANDESCENT (Burned out or blackened) 12 LAMPS FLUORESCENT (Burned out, faulty, low voltage bl ackened} REMARKS AND RECOMMENDATIONS DISPOSITION OF WORK SHEET THIS WORK SHEET SHOULD BE HELD IN THE POST ELECTRICAL MAINTENANCE FILE UNTIL REPAIRS ARE COMPLETED AND INFORMATION RECORDED ON MAINTENANCE SCHEDULE W.D. .A.0.0. FORM NO.5-91 AND ALL TEST DATA PROPERLY RECORDED. IT MAY THEN BE DESTROYED. Figure 12. 34 WIRING SYSTEM Years_Year Months Make repairs to wiring and equipment in a permanent manner, using ap- proved materials. Temporary work saves little time, must be replaced later, and is a fire hazard. 1 General conditions. Make sure wiring is done in a workmanlike manner, cir- cuit arrangement is correct, circuits are not overloaded, and work conforms with National Electrical Code in all essentials. 2 Loose wires and connections. Inspect each building for loose wires, poor con- nections, bare conductors, unauthorized or nonstandard attachments, defective convenience outlets and switches, defective attachment cords, improper use or length of attachment cords, use of wiring or fixtures as support for extraneous items, and any condition likely to cause fire. 3 Lamp sizes. Report all lamps larger than standard prescribed for outlet and replace them with proper size lamps. DISTRIBUTION PANEL 4 General. Keep distribution-panel inclosure closed and locked if possible. Clean and remove dust or extraneous material. Check circuit identification and bring it up-to-date. See that fuse or switch cabinet is accessible for servicing. 4 Electrical staff checks and reports on performance of these operations. 5 Fuses. Check distribution panels for proper fusing. Make sure fuses are not larger than rated current-carrying capacity of conductor on any circuit. Detect and replace defective fuses which have been bypassed by any means. 5 Electrical staff checks and reports on performance of above operations. 6 Connections. Check security of all connections to panel. Note if wires, lugs, switch contacts, or fuses are hot, indicating poor contacts or overload. 6 Electrical staff checks and reports on performance of above operations. 7 Grounds. Use test lamp or other simple means to detect accidental grounds on system. 8 Load balance on circuits. Balance legs of a single-phase three-wire or three- phase four-wire system. Readings taken with a hook-on ammeter during normal-load period or a quick survey of the connected load on each circuit is usually sufficient. 9 Grounded neutral. Wherever possible, ground neutral to water system. Check continuity of ground wire. If system has a ground rod, test to make sure ground resistance does not exceed 25 ohms. LIGHTING FIXTURES 10 Reflectors and lamps. Clean lighting fixtures and lamps. Wash reflectors with soapy water and rinse with clean water. Dry-wiping is unsatisfactory as it invariably leaves dirt on reflector. 10 Electrical staff checks and reports on performance of above operations. 11 Lamps, incandescent. Replace burned-out or blackened lamp bulbs promptly to insure efficient illumination. 11 Electrical staff checks and reports on performance of above operations. 35 5 Years 3 Year Months 12 12 Lamps, fluorescent. Give fluorescent lighting special maintenance attention since auxiliary equipment is damaged when faulty or burned out lamps are not removed from circuit. Keep fluorescent tubes clean and note darkened tubes for replacement. Report faulty operation immediately to post engineer and request replacement of tubes which are darkened or not operating. A fluorescent lamp approaching the end of its life flashes on and off unless protected by starters to prevent blinking. Request immediate replacement of flashing lamps to prevent harmful continuous working of starter and failure due to overloading lamp ballast. Low voltage generally causes trouble with fluorescent-lamp installations. Check voltage if lamps are operating badly. Electrical staff checks and reports on performance of above operations. 10. Disposition of Work Sheets Completed inspection and maintenance work sheets are filed by the electrical supervisor until the information is entered on a permanent record. Special information on transformers is recorded on WD AGO Form 5-82 (pars. 6a, 7b, and 8a), and that relative to buildings on WD AGO Form 5-84 (par. 9a). A complete summary of maintenance performed is entered on WD AGO Form 5-91 (par. 3b). After all information is transferred to appropriate forms, work sheets may be discarded, SECTION III PREVENTIVE MAINTENANCE SERVICES AND TECHNICAL INSPECTIONS OF ELECTRIC MOTORS 11. General Modern motors are sturdily built and with, reasonable care give long continuous service. Post engineer electrical personnel are responsible for inspecting and maintaining all electric motors and for adhering to a strict, regular schedule in performing these duties. Frequency and thoroughness of inspection depends on such variable factors as continuity of operation, surrounding conditions, the equipment driven, and motor design. Additional detailed post engineer maintenance responsibilities are listed in paragraph 2. 12. First Echelon Preventive Maintenance The scope of first echelon maintenance of motors varies according to the user’s skill and tools. For example, mess-hall personnel are not expected to repair or adjust the refrigerator motor. However, attendants at water-pumping stations, central-heating plants, sewage-disposal plants, and cold-storage plants, and the refrigerator, heating, and engineer shop mechanics all have the necessary tools and ability to perform first echelon motor maintenance. The responsibilities of each of the above are set forth in paragraphs 13 and 14. The post engineer should designate installations where operators in charge are responsible for motor maintenance, and notify operators of their specific responsibilities. Final responsibility, however, rests with the electrical staff, who inspect motors semiannually and report on the performance of first echelon inspections and maintenance services. 13. First Echelon Preventive Maintenance by Unskilled Users The success of preventive maintenance of motors depends greatly on the cooperation of the equipment’s user, who constitutes the first echelon of preventive maintenance. First echelon maintenance for the unskilled user does not require electrical or mechanical skill. It consists of keeping the motor clean and free from obstructions to ventilation, and notifying the post engineer of unusual noises, sluggish starting, unusual sparking, or overheating. The user follows the first echelon preventive maintenance instructions on WD AGO Form 5-81 (“Motors” first echelon preventive maintenance) (fig. 13). This form is posted conspicuously on or near the motor-driven equipment. 14. First Echelon Preventive Maintenance by Plant Operators, Inspector-mechanics, or Other Skilled Users a. Duties. Skilled users such as plant operators and inspector-mechanics perform first echelon preventive maintenance on motors when so designated by the post engineer. (See par. 12.) Their duties include: (1) Keeping motors lubricated. (2) Keeping motors free from dirt or moisture. (3) Freeing the operating space of articles obstructing air circulation. (4) Checking oil level in sleeve bearing and replenishing as needed with SAE 10 grade of good mineral oil. Under heavy belt pull or high temperature a somewhat heavier oil should be used. See Supply Bulletin SB 10-139 for comparable government specifications. (5) Checking grease in ball or roller bearings as required by manufacturer’s specifications or as shown in paragraph 16. (6) Reporting the following conditions to the post engineer for correction by electrical staff: (a) Bearings leaking oil or missing oil-well cover. (b) Oil rings not operating freely or carrying insufficient oil. 36 37 MOTORS FIRST ECHELON PREVENTIVE MAINTENANCE CARE OF ELECTRIC MOTORS BY UNSKILLED USER TURN OFF SWITCH AND CALL THE POST ENGINEER IF UNUSUAL CONDITIONS ARISE: SUCH AS; 1. An Accumulation of Dirt or Moisture 2. Unusual Noises When in Operation 3* Overheating (Too hot for hand or odor of scorched insulation) 4. Sluggish or Difficulty in Coming Up to Speed 5. Continuous Sparking When In Operation DO NOT OBSTRUCT AIR CIRCULATION AROUND MOTOR W.D., A.G.O. FORM NO. 5-81 Figure IS. (c) Hot bearings. (d) Dirty brushes and commutator. (e) Motor not starting or failing to come up to speed normally. (/) Motor too hot by hand test. (g) Continuous or excessive sparking at brushes. b. FREQUENCY. For minimum frequency of inspections, see WD AGO Form 5-89 (Work sheet for motors or generators and preventive maintenance services). (See fig. 15 and par. 16.) Inspections above are covered on the work sheet under item numbers 1, 2, 3, 7, 8, 9, 10, 11, 12, 13, 16, 25, 26, and 27. First echelon maintenance personnel fill in the work sheet during each inspection and send the filled-in form to the electrical supervisor for entry in the motor record card. c. Training. Post engineer electrical personnel are responsible for training plant operators, inspector-mechanics, or other skilled users who perform first echelon preventive maintenance on motors. 15. Motor or Generator Record Cards The post engineer and electrical personnel prepare and use WD AGO Form 5-83 (fig. 14) as a permanent record of maintenance. A card is made up for all motors for which the post engineer has maintenance responsibility. Data at the top of the card is filled in during the first inspection and kept up-to-date during subsequent inspections. The back of the card provides spaces to record inspections made. For convenience in scheduling and controlling inspections, motor record cards should be divided into two groups: one for motors on which first echelon preventive maintenance is performed by unskilled users (par. 13), and the second for motors on which first echelon preventive maintenance is performed by skilled users or mechanics (par. 14). Group 1 motors are inspected by the electrical staff at 1-month, 6-month, and 1-year intervals; group 2 motors are inspected at 6-month and 1-year intervals. 1 WOMEN 38 “sdEC X 16. Work Sheet For Motors and Preventive Maintenance Instructions Use of WD AGO Form 5-89 (fig. 15), by all inspecting personnel insures uniform inspection and maintenance procedures, assists inspectors, and provides a means of reporting defects. More frequent checks than specified on this schedule should be made when advisable. For instructions on using the work sheet, see paragraph 3a. The instructions below supplement the work sheet, giving detailed procedures for each step. 39 W.D..A.G.O FORM NO 5-83 MOTOR OR GENERATOR RECORD CARD LOCATION BUILDING NUMBER DATE INSTALLED DATE REPLACED APPLICATION MANUFACTURER PARTS' BULLETIN H.P.-K.W. TYPE FRAME SERIAL NUMBER VOLTS: | I AC | | DC PHASE BEARINGS AMPS FREQ. DRIVE BRUSHES OVERLOAD PROTECTION RPM 1st ECHELON MAINTENANCE BY USER | REPAIRS AND OVERHAUL DATE 1NSPECTED WORK ORDER REPAIRS MADE- BY NATURE OF WORK MATERIALS USED ♦ (See reverse side for routine inspection record) "L ROUTINE INSPECTION RECORD MONTHLY MONTHLY MONTHLY SIX MONTHS DATE 1 NSPECTOR DAT E 1NSPECTOR DATE INSPECTOR DATE INSPECTOR YEARLY DATE 1 NSPECTOR J . 1 . t Figure 14. 40 W.D..A.G.O. FORM NO. 5-89 November 19*14 WORK SHEET FOR MOTORS OR GENERATORS AND PREVENTIVE MAINTENANCE SERVICES SPECIAL INSTRUCTIONS: See TM 5-681 for Detailed Instructions & Frocodures-See Mfr. Manual for Technical Information BUILDING NUMBER AND LOCATION ~ MOTOR SERIAL NUMBER OAT E MOTOR LOCATION DRIVEN EQUIPMENT LEGEND FOR MARKING INSP ECTOR SYMBOLS SATJ SFACTORY y_ ADJUSTMENT REQUIRED ANNUALLY 6 MONTHS REPAIROR REPLACEMENT n_ DEFECT U CO R R E CT E D INSPECT AND CORRECT ANNUALLY 6 MONTHS MONTHLY 1 OIL SEALS AND COVER 2 OIL RING 3 TEMP ERATURE 4 BELT, CHAIN OR GEAR PRESSURE 5 ALIGNMENT 6 END PLAY 7 LUBRICATION (011 level, fill) 7 LUBRICATION (Flush, refill. renew wicking) BALL OR ROLLER BEARINGS 4 LUBRICATION 8 VIBRATION 4 TEMPERATURE 9 GREASE RETENTION 10 BELTS, CHAIN OR GEAR PRESSURE 11 AL IGNM ENT 12 LUBRICATION (Grease) 12 LUBRICATION (Oil) BRUSHES 4 BRUSH HOLDERS 13 CLEAN 4 CHECK (Clean, check for chipping, heat cracks, loose connections, uneven wear ) 14 LENGTH 15 MOVEMENT 4 SPRING TENSION COMMUTATOR OR SLIP RINGS 16 CLEAN 17 MICA,HIGH BARS, UNEVEN WEAR (Clean, rough. high wear) ROTORS 18 SQUIRREL CAGE (Clean,loose bars local heating, fan blades) 19 WOUND (Clean, collector rings pitted or eccentric, connec- tions. wedges) REMARKS AND RECOMMENDATIONS MONTHLY PRO' 20 21 ECTIVE DEVICES 4 CONTROLS FUSES (Size, contacts STARTER 4 CONTROLS (Clean freedom of moving wear, excess heating) THERMAL OVERLOAD RELAY (Setting, rating, excess heating, con- STARTING CYCLE (Sluggish sparking, rated spee< TESTS 22 LOAD CHECK 23 CLEARANCE - ROTOR 4 STATOR 24 INSULATION RESIS. 4 GROUNDS MISCELLANEOUS CHECKS 1— UNUSUAL NO 1SES CLEAN i BLOWOUT WINDINGS GENERATORS (Operation check) STORAGE B ATTERI ES 32. charging equip- eent) 29 30 31 32 25 26 27 28 PROTECTION AGAINST MOISTURE MOTOR MOUNTING MOTOR TEMPERATURE VENTILATION ELECTRIC CONNECTIONS (Wiring, switches . fuses, DI SPOSITION OF WORK SHEET THIS WORK SHEET SHOULD RE HELD IN THE POST MAINTENANCE ELECTRICAL FILE UNTIL REPAIRS ARE COMPLETED AND INFORMATION RECORDED ON MAINTENANCE SCHEDULE K IL, A. G. 0. FORM NO. 5-91 AND ALL TEST DATA PROPERLY RECORDED. IT MAYTHEN .BE DESTROYED,_____________________________________________________________________________________________________ Figure 15. 41 Annually SLEEVE BEARINGS AND LUBRICATION Months Month Bearings and lubrication are of the greatest importance in motor care: analysis of motor failures shows that most of them are caused by lack of lubrication. Follow the manufacturer’s lubricating schedule and meet the motor-manufacturer’s specifications for oil or grease by using a comparable standard Army lubricant. (See WD SB 10-139.) 1 Oil seals and cover. See that oil filler caps are closed so dust and dirt cannot get into bearing. Make sure oil seals, well covers, and plugs are tight. Check for oil creeping along shaft toward windings. Oil escaping from a bearing means trouble. 2 Oil ring. Check oil ring to be sure it is free and turns with shaft. 3 Temperature. Check that bearing temperatures do not exceed 80° C. for open-type motors or 90° C. for totally-inclosed motors, or temperatures specified by the motor manufacturer. 4 Belt, chain, or gear pressure. See that belts are no tighter than necessary to prevent slipping. Note if belt-tightening adjustment is all taken up. See that driving gears are not meshed too tightly and are turning together easily. Check chains for evidence of wear or stretch. See that chains clear housing. Check lubrication, especially for excess grease and oil in bottom of housing. 5 Alignment. Maintain proper alignment between motor and the machine it drives to prevent excessive bearing pressure. Align flexible couplings properly so there is no noise or excessive use of flexible medium. 6 End play. Check motor to see that end thrust is not excessive and shaft has a reasonable axial float. 7 Lubrication. When an oil gauge is used, check oil level and fill to line on gauge. When journal size is less than 2 inches, stop motor to check oil level. 7 Flush and refill oil reservoir. (Increase frequency if motor is used for hard-driven service.) Use good grade mineral oil with proper viscosity to meet temperature conditions. Oils designated by Navy symbols 2110, 2135, or 3050, or special oil to manufacturer’s specification if required by service to be rendered, are suggested. Small motors with sleeve bearings usually do not have oil-level gauges. On such motors it is good practice to add 30 to 60 drops of oil every 6 months or every 1,000 hours of operation. Renew wick or waste packing when glazed. BALL OR ROLLER BEARINGS AND LUBRICATION Follow the manufacturer’s lubricating schedule and meet the motor-manufacturer’s specifications for oil or grease by using a comparable standard Army lubricant. (See WD SB 10-139.) 8 Vibration and temperature. Feel housing for vibration and listen for unusual noises. Check that temperature does not exceed 80° C. for open-type motors or 90° C. for totally-inclosed motors, or temperatures specified by motor manufacturer. 9 Grease retention. Inspect for grease or oil creeping along shaft on inside of motor. Grease or oil escaping from a bearing means trouble and damages windings. 10 Belts, chain, or gear pressure. See item 4 above. 42 Annu- 6 ally_Months Month 11 Alignment. See item 5 above. 12 Lubrication. Lubrication required depends on how the motor is used. Average lubricating period is every 2 months for motors with grease-lubricated ball or roller bearings which are hard driven and on 24-hour service, and every 9 to 12 months for motors on light duty. On hard-driven motors, purge out old grease through drain hole and refill. Do not mix greases of different type or specifications. If change is desired, clean housing completely. Use special ball- and roller-bearing grease, Army specifications now pending. (See OFSB 6-2.) For general-purpose use at all temperatures, Gargoyle BRB No. 4 grease is suggested. 12 Lubrication. The amount of oil needed to lubricate small motors equipped with oil-lubricated bearings varies considerably, depending on severity of service and number of hours the motor operates. Adding 30 to 60 drops for every 1,000 hours is generally good practice. Oils designated by Navy symbols 2110, 2135, or 3050 are suggested. Motors on continuous 24-hour schedule require special lubrication in accordance with load conditions. BRUSHES AND BRUSH HOLDERS 13 Clean and, check. If brushes stick in holder clean holder and brush so brush works freely. If dirt and oil accumulate on commutator, faces of brushes become glazed and packed with dirt, causing harmful sparking. True up brushes worn unevenly or replace with a new set. Check pigtail connections for looseness. Examine brush faces for chipped toes or heels and for heat cracks. Replace those found damaged. 14 Length. If brushes are worn so they do not touch commutator or touch it only lightly, replace them. For best results, use brushes of grade and rating recommended by manufacturer. A set of brushes should last for at least 2,500 hours. Keep spare brushes for all type motors on post in the electrical shop and identify them clearly, preferably by a number. Enter number on WD AGO Form 5-83. 15 Movement and, spring tension. If brush pressure is incorrect, correct it by adjusting spring tension. If brush pressure is uneven or brush springs are weak, replace springs. Do not try to correct uneven feed by bending springs. To prevent grooving of the commutator, stagger pairs of brushholder arms about % inch in an axial direction. COMMUTATOR OR SLIP RINGS 16 Clean. Check commutator to make certain it is clean because oil and dirt make good commutation impossible. Commutator should be clean, smooth, and polished brown in color. A bluish color indicates overheating. Reversing polarity of slip ring brushes will tend to eliminate pitting of slip ring. 17 Mica, high bars, uneven wear. Wear on slip rings and commutators of elec- tric motors is inevitable because these rotating parts are exposed to constant friction, but cannot be lubricated. Minimize wear on commutators and slip rings by preventing grooving. Wipe abrasive dust from the surface of slip rings and commutators. Finish rough or uneven surface of rings or commutators at the first opportunity by sanding with No. 00 sandpaper, grinding, or turning down, depending on depth of surface roughness. Do not use emery cloth. If mica is high, cut it down slightly below level of commutator so brushes make contact with commutator bars. 43 Annu- 6 ally Months Month ROTORS 18 Squirrel cage. Check for broken or loose bars and evidence of local heating. If fan blades are not cast in place, check for loose or missing blades. 19 Wound. Clean thoroughly around collector rings, washers, and connections. Tighten connections. If rings are pitted, spotted, or eccentric, have them refinished. See that all wedges over coils are tight. PROTECTIVE DEVICES AND CONTROLS 20 Fuses. For motor running protection, see that fuse ratings do not exceed 125 percent of capacity. Check fuse clips, starting switch, and connections for looseness or heating. 21 Starter and controls. Keep starter and controls tight, clean, dry, and oper- ating at rated voltage. Check freedom of moving parts. Test all connections for looseness and note any excess heating of parts. Note contact pressure, evidence of serious arcing, and remaining wear allowance on contacts. Replace or repair contacts as needed. Check thermal-overload relays for proper rating and setting; watch for signs of defective contacts and overheating of parts. Check condition of heating element and replace if necessary. See that starter or control provides proper starting cycle for service intended and that thermal units and relays give proper overload and no-voltage protection. On single-phase motors, check for sluggish starting, excessive sparking, and failure to attain full rated speed. TESTS 22 Load check. Check load on motor whenever change is made in duty performed or motor shows tendency to overheat. A reading with hook-on ammeter usually is sufficient check. 23 Clearance between rotor and stator. Use long feeler gauges to check air gap between rotor and stator on 1-horsepower and larger motors. Clearance of rotor shows an experienced motor man the amount of wear in bearings. Exact clearance varies with motor size, speed, and manufacture so permissible limits are not well defined. A variation of 10 percent from average is usually permissible. A record of such yearly checks gives a picture of bearing wear. 24 Insulation resistance and grounds. Test insulation on all motors over 5 horse- power; this includes motors driving important loads such as water pumps, sewage pumps, boiler-feed pumps, stokers, etc. On motors of 5 horsepower or less, test insulation on a representative group of motors. Make insulation tests by using a megger-type instrument or an electronic ohmmeter of proper sensitivity. Make tests between coils and frame and between individual coils. Do not check wet motors with a megger because the high voltage may break down insulation. Test wet motors with a low-voltage ohmmeter. For further test information, interpretation of results, and criteria for insulation resistance, see TM 5-680. Note. Individual posts should not purchase meggers for this work but should obtain them from service command headquarters or the local utility company. MISCELLANEOUS CHECKS 25 Motor temperature. Check temperature by hand. Motor is not too hot if hand can be held on it with reasonable comfort. Most open-type motors are designed to operate safely with a temperature rise of 40° C., above an ambient 44 ally__Months Month of 40° C., ambient being air temperature in immediate vicinity of motor. This gives a stator temperature of 80° C. Wartime practice permits operation up to 90° C., 194° F. Totally-inclosed motors are usually designed to operate at temperatures up to 90° C. This temperature should not be exceeded by more than 5° C. at any time. 26 Ventilation. Examine ventilating openings to see that they are not restricting flow of air through motor. Remove unusual accumulation of dirt on housing, such as occurs in carpenter shops, etc. Do not permit any obstruction to air circulation around a motor. 27 Unusual noises. Locate cause of any unusual noise and take steps necessary to correct it. 28 Electrical connections. Make all electrical connections in a workmanlike man- ner and in accordance with the code for the service intended. Check electrical connections for conformance with National Electric Code. Check all wiring, switches, fuses, lugs, and joints for loose connections. 29 Protection against moisture. Make sure motor is shielded against drippings from sweating pipes or other sources. Do not obstruct free circulation of air around motor when correcting this condition. 30 Motor mounting. Insure that entire setting is secure and mounting bolts tight. 31 Clean and blow out zvindings. Blow dust from motors before it unites with water or oil to form a gummy substance. Wipe all dust from motor housings, slip rings, and commutators and blow dust from windings with a portable motor-driven low-pressure blower or with compressed air; do not use more than 40 pounds pressure. If neither is available, use hand bellows. Compressed air must be free from grit, metal, or moisture. If oil or grease has worked its way into rotor or stator windings, report the motor as requiring thorough cleaning with solvent. Ordinarily, the motor must be returned to the shop for this operation. 32 Generators. Test stand-by electric generators at least monthly to check functioning of starting apparatus and to keep operators familiar with starting procedures. Check automatic-starting equipment, power change-over switches, and similar equipment to see that proper starting cycle is produced. Operate generator under normal load for 1 or 2 hours if possible. Observe any distress of generator, prime mover, or related equipment. Check for excess heating, lubrication, etc., as provided in preceding paragraphs. Make momentary starting checks weekly to make sure equipment is ready to operate. 32 Storage batteries. If storage batteries are used, check electrolyte for proper level and specific gravity. Check operation of charging equipment. 17. Disposition of Work Sheets Completed inspection and maintenance work sheets are filed by the electrical supervisor until the information is entered on a permanent record. Special information on motors and generators is recorded on WD AGO Form 5-83 (par. 15). A complete summary of maintenance performed is entered on WD AGO Form 5-91 (par. 36). After all information has been properly recorded on a permanent record, the work sheet may be destroyed. ★ U. S. GOVERNMENT PRINTING OFFICE: 1945-657661-TM 254 UNT LIBRARIES DENTON TX 7(203 ■himin ini 1001895436