2024-05933. Petition for Modification of Application of Existing Mandatory Safety Standards

AGENCY:

Mine Safety and Health Administration, Labor.

ACTION:

Notice.

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 April 22, 2024.

ADDRESSES:

You may submit comments identified by Docket No. MSHA–2024–0003 by any of the following methods:

1. Federal eRulemaking Portal: https://www.regulations.gov. Follow the instructions for submitting comments for MSHA–2024–0003.

2. Fax: [phone].

3. Email: [e-mail].

4. Regular Mail or Hand Delivery: MSHA, Office of Standards, Regulations, and Variances, 201 12th Street South, 4th Floor West, Arlington, Virginia 22202–5452,

Attention: S. Aromie Noe, Director, Office of Standards, Regulations, and Variances. Persons delivering documents are required to check in at 4th Floor West. 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), [e-mail] (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–2024–001–C.

Petitioner: River View Coal, LLC, 835 St. Route 1179, Waverly, Kentucky 42462.

Mine: Henderson County Mine, MSHA ID No. 15–02709, located in Union County, Kentucky.

Regulation Affected:30 CFR 18.35(a)(5)(i) (Portable (trailing) cables and cords).

Modification Request: The petitioner requests a modification of 30 CFR 18.35(a)(5)(i) to increase the maximum length of tailing cables to supply power to permissible equipment used in continuous mining sections.

The petitioner states that:

(a) The mine will be developing three in-seam slopes, approximately 1000 feet in length each. When completed, the 9-degree slopes will be utilized to connect two vertically separated coal seams.

(b) The mine will routinely mine around oil wells which require leaving large barrier pillars to protect the wells and the underground miners.

(c) Accomplishing these mining scenarios safely and efficiently necessitates extended cable lengths, without the need to provide permissible junction boxes that would otherwise be installed and maintained in the direct paths of haulage equipment.

The petitioner proposes the following alternative method:

(a) The proposed decision and order (PDO) granted by MSHA shall apply only to trailing cables supplying three-phase 995-volts alternating current (VAC) power to continuous mining machines, supplying three-phase 480–VAC power to roof bolting machines, and supplying power to 550-volts direct current (VDC) shuttle cars.

(b) During construction of the inner-seam slope between the 11 and 9 seams, the maximum length of trailing cables shall be 1,200 feet. At all other times, the maximum length of trailing cables shall be 850 feet.

(c) Cables supplying power to:

(1) 995–VAC continuous mining machines shall not be smaller than 2/0 .

(2) 480–VAC roof bolting machines shall not be smaller than #2 AWG.

(3) 550–VDC shuttle cars shall not be smaller than # 2/0 AWG.

(d) Circuit Breakers used to protect 2/0 trailing cables from 850 feet to 950 feet in length supplying power to 995–VAC continuous mining machines shall have instantaneous trip units calibrated to trip at 1,500 amps. A password protected Schweitzer Engineering Laboratories (SEL) relay shall control the trip setting of these vacuum circuit breakers to ensure that the settings cannot be changed. These vacuum circuit breakers shall have a permanent legible label identifying the circuit breaker as being suitable for protecting 2/0 cables supplying power to the specified machines.

(e) Circuit breakers used to protect 2/0 trailing cables over 950 feet to 1,200 feet in length supplying power to 995–VAC continuous mining machines shall have instantaneous trip units calibrated to trip at 1,400 amps. A password protected SEL relay shall control the trip setting of these vacuum circuit breakers to ensure that the settings cannot be changed. These vacuum circuit breakers shall have a permanent legible label identifying the circuit breaker as being suitable for protecting 2/0 cables supplying power to the specified machines.

(f) Circuit breakers used to protect #2 AWG cables from 700 feet to 900 feet in length supplying power to 480–VAC roof bolting machines shall have instantaneous trip units calibrated to trip at 800 amps. The trip setting of these circuit breakers shall be sealed to ensure that the settings cannot be changed. These circuit breakers shall have permanent legible labels identifying the circuit breaker as being suitable for protecting #2 AWG cables supplying power to the specified machines.

(g) Circuit breakers used to protect #2 AWG cables over 900 feet to 1,200 feet in length supplying power to 480–VAC roof bolting machines shall have instantaneous trip units calibrated to trip at 700 amps. The trip setting of these circuit breakers shall be sealed to ensure that the settings cannot be changed. These circuit breakers shall have permanent legible labels identifying the circuit breaker as being suitable for protecting #2 AWG cables supplying power to the specified machines.

(h) Circuit breakers used to protect # 2/0 AWG cables from 850 feet to 1,200 feet in length supplying power to 550–VDC shuttle cars shall have an instantaneous trip units calibrated to trip at 700 amps. The trip setting of these circuit breakers shall be sealed to ensure that the settings cannot be changed. These circuit breakers shall have permanent legible labels identifying the circuit breaker as being suitable for protecting # 2/0 AWG cables supplying power to the specified machines. As specified in 30 CFR 75.703–3(d)(5), grounding diodes must have a nominal current rating of no less than 250 amps.

(i) Replacement circuit breakers and instantaneous trip units used to protect trailing cables shall be calibrated, sealed, and labeled as specified in the PDO granted by MSHA.

(j) All components that provide short-circuit protection shall have a sufficient interruption rating in accordance with the maximum calculated fault currents available. All circuit breakers used to protect trailing cables exceeding the maximum length specified in 30 CFR 18.35(a)(5)(i) shall have instantaneous trip units properly calibrated and adjusted to trip at no more than the smallest of the following values:

(1) The setting specified in 30 CFR 75.601–1;

(2) The setting specified in the approval documentation for the machine; or

(3) 70 percent of the minimum phase to phase short circuit current available at the end of the trailing cable.

(k) The short circuit analysis shall be updated whenever changes are made to the mine power system that affect the fault current available at the end of the affected trailing cables and the specified settings used to protect these trailing cables. An updated short circuit analysis which accurately determines the minimum phase to phase short circuit current available at the end of the affected trailing cables shall be made available to MSHA personnel upon request.

(l) During each production shift, persons designated by the mine operator shall visually examine the trailing cables to ensure that they are in safe operating condition. The instantaneous settings of the specifically calibrated circuit breakers shall also be visually examined to ensure that the seals or locks have not been removed and that they do not exceed the settings specified in the PDO granted by MSHA.

(m) Any trailing cable that is not in safe operating condition shall be removed from service immediately and repaired or replaced.

(n) Each splice or repair in the trailing cables shall be made in a workman-like manner and in accordance with the instructions of the manufacturer of the splice repair materials. The outer jacket of each splice or repair shall be vulcanized with flame resistant material or made with material that has been accepted by MSHA as flame resistant. Splices shall comply with the requirements of 30 CFR 75.603 and 75.604.

(o) Permanent warning labels shall be installed and maintained on the cover(s) of the power center or distribution box identifying the location of each sealed or locked short-circuit protective device. These labels shall warn miners not to change or alter these sealed short-circuit settings, and any sign of tampering with the specially calibrated circuit breaker or trip unit will require the replacement of the circuit breaker with another calibrated, sealed and/or locked trip unit. All cable couplers for these cables shall be constructed or designed, for example keyed or sized, to permit only the proper type and length of cable to be plugged into the receptacle with the proper settings.

(p) If the mining methods or operating procedures cause or contribute to the damage of any trailing cable, the cable shall be removed from service immediately and repaired or replaced. Additional precautions shall be taken to ensure that haulage roads and trailing cable storage areas are situated to minimize contact of the trailing cable with continuous mining machines, roof bolting machines, and shuttle cars. Trailing cable anchors on cable reel equipment shall be of the permanent type that minimizes the tensile forces on the trailing cables.

(q) Where the method of mining requires that trailing cables cross roadways or haulage ways, the cables shall be securely supported from the mine roof, or a substantial bridge for equipment to pass over the cables shall be provided and used.

(r) Excessive cable shall be stored behind the anchor on equipment that uses cable reels to prevent cables from overheating.

(s) The PDO granted by MSHA alternate method shall not be implemented until miners who have been designated to examine the integrity of seals or locks, verify the short circuit settings, and examine trailing cables for defects and damage, have received the training as detailed in section (y).

(t) Within 60 days after the PDO granted by MSHA becomes final, the petitioner shall submit proposed revisions for its approved 30 CFR part 48 training plan to the Mine Safety and Health Enforcement District Office for the District which the mine is located. The training shall include the following elements:

(1) Mining methods and operating procedures that will protect the trailing cables against damage;

(2) Proper procedures for examining the trailing cables to ensure that they are in safe operating condition;

(3) Hazards of setting the instantaneous circuit breakers too high to adequately protect the trailing cables;

(4) How to verify that the circuit interrupting device(s) protecting the trailing cable(s) is properly set and maintained; and

(5) How to protect trailing cables against damage caused by overheating when excessive cable is stored on the cable reel and the importance of adjusting stored cable behind the cable anchor as tramming distances change.

In support of the proposed alternative method, the petitioner submitted short circuit analyses for 950 feet and 1,200 feet lengths of cable for 995–VAC, 900 feet and 1,200 feet lengths of cable for 480–VAC, and 850 feet and 1,200 feet lengths of cable for 550–VDC to demonstrate that there is enough current available to trip the short circuit protection at the time of a fault. Pictures of the ground fault detection diode assembly and detailed technical information of the rectifier diode were also provided.

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.