On January 29, 1985, a petition was filed seeking a modification of the application of 30 CFR 75.1002 (Docket No. M-85-009-C) to Petitioner’s No. 7 Mine, located in Tuscaloosa County, Alabama. The petition was granted on June 20, 1986, and became final on August 1, 1986. On October 28, 1996, Petitioner filed a petition (Docket No. M-96-148-C) to amend Paragraph 9 of the granted modification. The current Paragraph 9 reads as follows:
The high-voltage circuit from the longwall power center to the longwall controller shall be provided with short-circuit protection set at not more than 2,000 amperes. A time delay of not more than 0.1 second shall be permitted for coordination with downstream short-circuit protection devices.
The Petitioner requests that Paragraph 9 be amended to read as follows:
The high-voltage circuit from the longwall power center to the longwall controller shall be provided with short-circuit protection set at not more than 2,500 amperes or the value of current indicated in the longwall approval plan. A time delay of not more than 0.25 second shall be permitted for coordination with downstream short-circuit protection devices or the time delay specified in the Longwall Approval Plan.
During MSHA’s investigation Petitioner also asked that Paragraph 11 of the granted modification be amended. Paragraph 11 currently reads as follows:
Where a high-voltage cable that moves during normal operation of the longwall is damaged to the extent that any metallic component of the cable is damaged, the cable shall be removed from service and repaired in a cable repair shop. The outer jacket of such repair shall be vulcanized with flame-resistant material.
The Petitioner requests that Paragraph 11 be amended to read as follows:
Where a high-voltage cable that moves during normal operation of the longwall is damaged, the cable shall be removed from service and repaired by properly trained and qualified personnel. The outer jacket of such repair shall be vulcanized with flame resistant material.
In addition, during MSHA’s investigation a commenter requested a new Paragraph 22 be added as part of petition M-96-148-C. This new paragraph reads as follows:
A caution statement shall be installed and maintained on all power center doors and covers which reads - Danger High Voltage Do Not Enter.
Comments were also received from the United Mine Workers of America (UMWA) concerning the Petition for Modification. It requested that Paragraph 12 of the original modification (M-85-009-C) be amended to include the wording of more recently granted modifications. Paragraph 12 of the original petition reads as follows:
High-voltage cables shall be guarded at the following locations:
(a) Where miners regularly work or travel over or under the cables; and
(b) Where the cables leave cable handling and support systems to extend to electric components.
The guarding shall protect the cables from damage and shall prevent miners from contacting the cables. The guarding shall be of grounded metal or nonconductive, flame-resistant material.
The UMWA requests that Paragraph 12 be amended to read as follows:
High-voltage cables shall be guarded at the following locations:
(a) Where miners regularly work or travel over or under the cables; and
(b) Where the cables leave cable handling and support systems to extend to electric components.
The guarding shall protect the cables from damage and shall minimize miners’ contact with the cables. The guarding shall be of grounded metal or reinforced non-conductive, flame-resistant material. Additional guarding, unless the high-voltage cable is deenergized, shall be provided on high-voltage cables in belt conveyor entries during cleanup and belt structure removal if the cables are within 12 inches of mobile equipment.
The Petitioner alleges that the alternative method outlined in the amended petition will at all times guarantee no less than the same measure of protection provided by the standard. This PDO (Docket No. M-96-148-C), when final, shall supersede the modification granted for 75.1002 in Docket No. M-85-009-C.
MSHA investigators conducted an investigation into the merits of the petition and filed a report of their findings and recommendations with the Administrator, Coal Mine Safety and Health. After a careful review of the entire record, including the petition, comments, and MSHA’s investigative report and recommendation, the Proposed Decision and Order is issued.
The alternative method proposed by Petitioner (as amended by the recommendations of MSHA investigators) will at all times guarantee no less than the same measure of protection afforded the miners under 30 CFR 75.1002.
On the basis of the petition and the findings of MSHA’s investigation, Jim Walter Resources, Incorporated, is entitled to a modification of the application of 30 CFR 75.1002 to its No. 7 Mine.
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator, Coal Mine Safety and Health, and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C., sec. 811(c), it is ordered that Jim Walter Resources, Incorporated’s Petition for Modification of the application of 30 CFR 75.1002 in the No. 7 mine is hereby:
GRANTED, Conditioned upon compliance with the following terms and conditions:
1. The nominal voltage of the longwall power circuits shall not exceed 2,400 volts.
2. The nominal voltage of the longwall control circuits shall not exceed 120 volts.
3. Ground-fault current shall be limited by a neutral grounding resistor to not more than 6.25 amperes.
4. Each high-voltage motor circuit shall be provided with instantaneous ground-fault protection set at not more than 40 percent of the current rating of the neutral grounding resistor.
5. The high-voltage circuit from the longwall power center to the longwall controller shall be provided with ground-fault protection set at not more than 40 percent of the current rating of the neutral grounding resistor. A time delay of not more than 0.1 second shall be permitted for coordination with downstream ground-fault protection devices.
6. The longwall power center shall be provided with backup ground-fault protection that will deenergize the high-voltage circuit to the longwall controller if a ground fault occurs with the neutral grounding resistor open.
7. The high-voltage neutral grounding resistor shall be provided with over temperature protection that will open the ground check circuit for the high-voltage circuit supplying the longwall power center if the grounding resistor is subjected to a sustained ground fault.
8. Each high-voltage motor circuit shall be provided with instantaneous short-circuit protection set at not more than 125 percent of the locked-rotor current of the motor.
9. Each high-voltage circuit supplying power from a longwall power center to a high-voltage starter enclosure shall be provided with short-circuit protection set at not more than the setting specified in the longwall approval documentation or 2,500 amperes, whichever is less. The time delay shall be set at the lowest practical value that permits reliable coordination; however, in no case shall the time delay exceed .250 second.
10. Each high-voltage cable installed as part of the longwall mining system shall be type SHD-GC, shall have a 5,000-volt rating, and shall have an outer jacket that has been accepted by MSHA as flame-resistant.
11. Each splice or repair in a high-voltage longwall cable shall be made, by a qualified person (as provided in 30 CFR 75.153), in a workmanlike manner and in accordance with the instructions of the manufacturer of the splice or repair materials. The outer jacket of each splice or repair shall be vulcanized with flame-resistant material that has been accepted by MSHA as flame-resistant. Each splice or repair shall be made so that all cable components are replaced with similar components.
12. High-voltage cables shall be guarded at the following locations:
(a) Where miners regularly work or travel over or under the cables; and
(b) Where the cables leave cable handling and support systems to extend to electric components.
The guarding shall protect the cables from damage and shall minimize miners’ contact with the cables. The guarding shall be of grounded metal or reinforced non-conductive, flame-resistant material. Additional guarding, unless the high-voltage cable is deenergized, shall be provided on high-voltage cables in belt conveyor entries during cleanup and belt structure removal if the cables are within 12 inches of mobile equipment.
. 13. Cable handling and support systems that are designed, installed, and maintained to protect the high-voltage cables from damage shall be used to minimize the possibility of miners contacting the cables.
14. Miners shall wear high-voltage, insulating gloves while handling or moving energized high-voltage cables.
15. The longwall controller shall be provided with a main high-voltage disconnect switch. The disconnect switch shall be designed and installed so that it can be determined by visual observation that the switch contacts are open without removing any of the controller covers.
16. A means shall be provided for grounding the load side of the main disconnect switch without removing any f the controller covers.
17. Barriers shall be provided and covers shall be arranged so that miners can work in the lighting transformer and vacuum contactor compartments of the longwall controller without being exposed to energized high-voltage conductors or parts when the main disconnect switch in the open position.
18. Barriers shall be provided and covers shall be arranged so that miners can work in the control and communication compartments of the longwall controller without being exposed to energized high-voltage conductors or parts regardless of the position of the main disconnect switch.
19. The longwall controller shall be provided with cover interlock switches as follows:
(a) Cover interlock switches shall be provided to automatically deenergize the associated high-voltage output circuit when any high-voltage cable output compartment cover is removed; and
(b) Cover interlock switches shall be provided to automatically deenergize the high-voltage circuit supplying the longwall controller when any other controller cover that provides access to energized high-voltage conductors or parts is removed.
20. Before any electrical work (including testing, trouble-shooting, and fault finding) is performed inside the lighting transformer and vacuum contactor compartments of the controller or on any high-voltage cable or equipment supplied from the controller, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the contacts of the main disconnect switch in the controller are open and grounded; and
(b) Lock out and tag the main disconnect switch in the controller.
21. Before any electrical work (including testing, trouble-shooting, and fault finding) is performed inside the main disconnect switch compartment of the controller or on the high-voltage cable supplying the controller, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the high-voltage cable is disconnected from the longwall power center;
(b) Connect the phase conductors in the high-voltage cable to the grounding conductors in the cable at the longwall power center; and
(c) Lock out and tag the cable coupler for the cable at the longwall power center.
22. Caution labels shall be installed and maintained on the covers of the compartments of the longwall power center, starter enclosure, disconnecting device or shearing machine containing high-voltage components warning miners against entering these compartments before de-energizing the input to the compartment.
23. Within sixty (60) days after this Proposed Decision and Order becomes final, the Petitioner shall submit proposed revisions for its approved 30 CFR Part 48 training plan to the Coal Mine Safety and Health District Manager. These proposed revisions shall specify task and refresher training regarding the terms and conditions stated in the Proposed Decision and Order.
Any party to this action desiring a hearing on this matter must file in accordance with 30 CFR 44.14, within 30 days. The request for hearing must be filed with the Administrator for Coal Mine Safety and Health, 4015 Wilson Boulevard, Arlington, Virginia 22203.
If a hearing is requested, the request shall contain a concise summary of position on the issues of fact or law desired to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than Petitioner who has requested a hearing shall also comment upon all issues of fact or law presented in the petition, and any party to this action requesting a hearing may indicate a desired hearing site. If no request for a hearing is filed within 30 days after service thereof, the Decision and Order will become final and must be posted by the operator on the mine bulletin board at the mine.
_________________________________
Robert A. Elam
Deputy Administrator
for Coal Mine Safety and Health
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