[Federal Register Volume 88, Number 198 (Monday, October 16, 2023)]
[Notices]
[Pages 71380-71381]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-22742]


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DEPARTMENT OF LABOR

Mine Safety and Health Administration


Petition for Modification of Application of Existing Mandatory 
Safety Standards

AGENCY: Mine Safety and Health Administration, Labor.

ACTION: Notice.

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SUMMARY: This notice is a summary of a petition for modification 
submitted to the Mine Safety and Health Administration (MSHA) by the 
party listed below.

DATES: All comments on the petition must be received by MSHA's Office 
of Standards, Regulations, and Variances on or before November 15, 
2023.

ADDRESSES: You may submit comments identified by Docket No. MSHA-2023-
0035 by any of the following methods:
    1. Federal eRulemaking Portal: https://www.regulations.gov. Follow 
the instructions for submitting comments for MSHA-2023-0035.
    2. Fax: 202-693-9441.
    3. Email: [email protected].
    4. Regular Mail or Hand Delivery: MSHA, Office of Standards, 
Regulations, and Variances, 201 12th Street South, Suite 4E401, 
Arlington, Virginia 22202-5452, Attention: S. Aromie Noe, Director, 
Office of Standards, Regulations, and Variances. Persons delivering 
documents are required to check in at the receptionist's desk in Suite 
4E401. Individuals may inspect copies of the petition and comments 
during normal business hours at the address listed above. Before 
visiting MSHA in person, call 202-693-9455 to make an appointment, in 
keeping with the Department of Labor's COVID-19 policy. Special health 
precautions may be required.

FOR FURTHER INFORMATION CONTACT: S. Aromie Noe, Office of Standards, 
Regulations, and Variances at 202-693-9440 (voice), 
[email protected] (email), or 202-693-9441 (fax). [These 
are not toll-free numbers.]

SUPPLEMENTARY INFORMATION: Section 101(c) of the Federal Mine Safety 
and Health Act of 1977 and title 30 of the Code of Federal Regulations 
(CFR) part 44 govern the application, processing, and disposition of 
petitions for modification.

I. Background

    Section 101(c) of the Federal Mine Safety and Health Act of 1977 
(Mine Act) allows the mine operator or representative of miners to file 
a petition to modify the application of any mandatory safety standard 
to a coal or other mine if the Secretary of Labor determines that:
    1. An alternative method of achieving the result of such standard 
exists which will at all times guarantee no less than the same measure 
of protection afforded the miners of such mine by such standard; or
    2. The application of such standard to such mine will result in a 
diminution of safety to the miners in such mine.
    In addition, sections 44.10 and 44.11 of 30 CFR establish the 
requirements for filing petitions for modification.

II. Petition for Modification

    Docket Number: M-2023-012-C.
    Petitioner: Warrior Met Coal Mining, LLC, 16243 Highway 216, 
Brookwood, Alabama 35444.
    Mine: No. 4 Mine, MSHA ID No. 01-01247, located in Tuscaloosa 
County, Alabama. No. 7 Mine, MINE ID No. 01-01401, located in Jefferson 
County, Alabama.
    Regulation Affected: 30 CFR 75.900, Low- and medium-voltage 
circuits serving three-phase alternating current equipment; circuit 
breakers.
    Modification Request: The petitioner requests a modification of 30 
CFR 75.900 to permit use of a contactor or a Variable Frequency Drive 
(VFD) in series with the circuit breaker, in lieu of a circuit breaker 
alone.
    The petitioner states that:
    (a) The mine uses continuous mining machinery and longwall mining 
machinery,
    (b) Miners have been injured setting a circuit breaker which 
creates a phase-to-phase fault resulting in an arc flash.
    (c) The alternative method places the contactor or VFD between the 
circuit breaker and load, minimizing the possibility of closing into a 
fault. The use of a vacuum contactor to clear a fault has no arc flash 
when the fault is cleared.
    (d) A VFD will control or limit the inrush current to the connected 
load as compared to starting across the line. This provides less stress 
on the electrical system and allows the operator to set the 
instantaneous trip on the circuit breaker at lower than the maximum 
allowed setting.
    (e) The petitioner currently uses a combination of a circuit 
breaker and a contactor on continuous mining machine sections to power 
up continuous mining machines, roof bolters, feeders, ventilation fans, 
and chargers.
    (f) The petitioner currently uses a circuit breaker and VFD 
combination out-by on conveyor belt systems.
    (g) The combination of circuit breakers with a contactor or VFD 
will provide short circuit, undervoltage, grounded phase, and 
overcurrent protection.
    The petitioner proposes the following alternative method:
    (a) The petitioner shall use a contactor in series with a circuit 
breaker instead of a circuit breaker alone. The contactor shall provide 
protection from undervoltage and grounded phase. The circuit breaker 
shall provide short circuit protection and overcurrent protection (when 
applicable).
    (1) Contactors shall be rated for the maximum voltage of the 
circuit being protected.
    (2) Contactors shall be rated for the continuous full load current 
of the equipment.
    (3) The nominal voltage of the power circuits(s) shall not exceed 
995 volts.
    (4) The nominal voltage of the control circuit(s) shall not exceed 
120 volts.
    (5) Contactors and associated protective relays shall provide 
undervoltage protection causing the contactor to open when an 
undervoltage exists.
    (6) Undervoltage protection shall be provided in two ways:
    (i) If the supply voltage to the ground monitor drops below 68 
percent, the ground monitor will trip, dropping out the GMAUX relay and 
thereby removing power from the vacuum contactor coil, thus opening the 
contactor. The ground monitor trip will be a latching fault that 
requires a manual reset; and
    (ii) In the alternative, undervoltage protection will be provided 
by contactors that will drop out at 50 and 60 percent of supply 
voltage.
    (7) Grounded phase protection shall be provided using a ground 
fault relay. When the relay trips on a ground fault condition, the 
contact tips shall open removing power to the vacuum contactor coil 
that shall open the contactor. The ground fault relay shall be a 
latching fault that will require a manual reset.
    (8) Contactors shall be located in the same main enclosure as the 
circuit breaker.
    (9) Each circuit breaker installed in series with a contactor shall 
be equipped with devices to provide short-circuit protection for each 
piece of equipment.
    (10) Ground fault and ground monitor trips shall not automatically 
reset and

[[Page 71381]]

must require a manual reset before the contactor can be closed.
    (11) Fail-safe ground check circuits shall cause the contractor to 
open when either the ground or pilot wire is broken.
    (12) A monthly examination shall be conducted on each circuit to 
ensure proper operation of the contactor.
    (13) The monthly examination shall include activating undervoltage, 
ground fault, and ground monitor trip devices. The results of the 
contactor test shall be recorded with the required circuit breaker 
monthly tests.
    (b) The petitioner shall use a Variable Frequency Drive (VFD) in 
series with a circuit breaker instead of a circuit breaker alone. The 
circuit breaker shall provide short circuit protection. A ground fault 
relay will provide grounded phase protection which will cause the 
circuit breaker to open. The VFD shall provide protection from 
undervoltage and overcurrent.
    (1) The VFD shall be rated for the maximum voltage of the circuit 
being protected.
    (2) The VFD shall be rated for the continuous full load current of 
the utilization equipment.
    (3) The nominal voltage of the control circuit(s) shall not exceed 
120 volts.
    (4) The VFD shall provide undervoltage protection. The VFD shall 
trip at 55 percent of the nominal voltage based on the parameter 
settings in the VFD that shall de-energize the output of the VFD.
    (5) The VFD shall provide over-current protection to the connected 
load. The VFD shall use an internal algorithm to protect the equipment 
based on a rated load. The VFD shall calculate the motor temperature 
based on current draw over time. If the motor temperature reaches the 
setpoint for the defined time, the VFD shall fault indicating a motor 
overload. This shall be a latching fault requires a manual reset.
    (6) A circuit breaker shall provide short circuit protection for 
systems using a VFD. A ground fault relay shall provide grounded phase 
protection by causing the breaker to open.
    (7) The VFD shall be located in the same main enclosure as the 
circuit breaker.
    (8) Each circuit breaker installed in series with a VFD shall be 
equipped with devices to provide short-circuit protection for each 
piece of equipment.
    (9) Ground fault and ground monitor trips shall not automatically 
reset and shall require a manual reset before the VFD would turn the 
output on.
    (10) Fail-safe ground check circuits shall cause the breaker to 
open when either the ground or pilot wire is broken.
    (11) A monthly examination shall be conducted on each circuit to 
ensure proper operation of the breaker and VFD.
    (c) Within 60 days after this proposed decision and order is 
granted, the petitioner shall submit proposed revisions to its part 48 
training plant to the appropriate MSHA District Official(s), specifying 
task training for all miners who are assigned to work in any pertinent 
area.
    (d) The training shall include the purpose of the contractor 
systems and VFD systems, the potential hazards of working on or near 
belt conveyors and belt conveyor drives, and the requirements of 30 CFR 
75.1725(c) and (d).
    (e) The requirements of 30 CFR 48.3 for approval of proposed 
revisions to existing approved training plans shall apply.
    The petitioner provided documentation to include typical control 
schemes, contactor specifications, VFD specifications, breaker 
specifications, ground monitor specifications, ground fault relay 
specifications, and coupler specifications in support of their 
petition.
    The petitioner asserts that the alternate method proposed will at 
all times guarantee no less than the same measure of protection 
afforded the miners under the mandatory standard.

Song-ae Aromie Noe,
Director, Office of Standards, Regulations, and Variances.
[FR Doc. 2023-22742 Filed 10-13-23; 8:45 am]
BILLING CODE 4520-43-P