In the matter of Petition for Modification
Eagle Energy, Incorporated
Mine No. 1
I.D. No. 46-07711 Docket No. M-98-027-C
PROPOSED DECISION AND ORDER
On February 20, 1998, a petition was filed seeking a modification of the application of 30 CFR 75.1002 to Petitioner’s Mine No. 1 located in Boone County, West Virginia. The Petitioner alleges that the alternative method proposed in the petition will at all times guarantee no less than the same measure of protection afforded by the standard.
MSHA personnel conducted an investigation of the petition and filed a report of their findings and recommendations with the Administrator for Coal Mine Safety and Health. After a careful review of the entire record, including the petition, comments, and MSHA’s investigative report and recommendation, this Proposed Decision and Order is issued.
Finding of Fact and Conclusion of Law
The alternative method proposed by the Petitioner (as amended by the recommendations of MSHA) 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, Eagle Energy, Incorporated is granted a modification of the application of 30 CFR 75.1002 to its Mine
No. 1.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for 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 Eagle Energy, Incorporated’s Petition for Modification of the application of 30 CFR 75.1002 in the Mine No. 1 is hereby:
GRANTED, for the 4,160-volt longwall conditioned upon compliance with the following terms and conditions:
1. The nominal voltage of the longwall high-voltage shearer circuit shall not exceed 4,160 volts. All other longwall power circuits shall not exceed 1,000 volts.
2. The nominal voltage of the longwall control circuit shall not exceed 120 volts. The control circuit transformer shall be provided with a Faraday shield that is properly installed and maintained.
3. Ground-fault current for the 4,160-volt circuits shall be limited by a neutral grounding resistor to not more than 3.75 ampere.
4. Each high-voltage motor circuit and shearer circuit shall be provided with instantaneous ground-fault protection set at not more than 40 percent of the ground-fault current limited by the neutral grounding resistor or 0.125 ampere, whichever is less.
5. The high-voltage circuit(s) 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 ground-fault current limited by the neutral grounding resistor or 0.125 ampere, whichever is less. A time delay may be permitted for coordination with the downstream ground-fault protection devices. The time delay shall be set at the lowest practical value that permits reliable coordination; however, in no case shall the time delay exceed 0.250 second.
6. The longwall power center shall be provided with backup ground-fault protection that shall deenergize the 4,160-volt circuit breaker if a ground-fault occurs with the neutral grounding resistor open. This protection shall be set at 40 percent of the maximum voltage that could appear across the neutral ground resistor if a ground-fault occurs. A time delay for coordination with downstream ground-fault protection devices shall be set at the lowest practical value that permits reliable coordination; however, in no case shall the time delay exceed 0.250 second.
7. The high-voltage neutral grounding resistor shall be provided with thermal protection that will deenergize the affected longwall power center if the grounding resistor is subjected to a sustained ground-fault. The thermal protection shall not be dependent upon control power and may consist of a current transformer and overcurrent relay in the grounding resistor circuit that will deenergize the power center.
8. Each high-voltage circuit shall be provided with instantaneous short-circuit protection set at not more than the setting specified in the longwall approval documentation or 75 percent of the minimum phase-to-phase short-circuit current available at the motor terminals, whichever is less. A time delay of not more than three cycles may be permitted for motors with high inrush currents. All components that provide short-circuit protection shall have sufficient interrupting rating to safely interrupt the maximum calculated available fault current and shall be installed to prevent automatic reclosure.
9. The 4,160-volt circuit(s) from the longwall power center to the longwall controller shall be provided with short-circuit protection by means of a high-voltage circuit breaker located in the longwall power center. This circuit breaker shall be set to open at not more than 75 percent of the minimum available phase-to-phase short-circuit current at the longwall controller or the setting specified in the longwall approval documentation, whichever is less. A time delay for coordination with downstream ground-fault protection devices shall be set at the lowest practical value that permits reliable coordination; however, in no case shall the time delay exceed 0.25 second.
Where two cables are used to supply power to the longwall controller and each cable has an overcurrent relay, each overcurrent relay shall be set at not more than 50% of the value specified above.
10. The grounding circuit between the longwall power center and a high-voltage longwall controller shall be monitored by an MSHA accepted ground monitor system. The ground-wire monitoring circuits shall deenergize each cable when the ground-monitor wires or grounding conductor(s) of any cable becomes severed or open. One circuit breaker shall be provided in the power center to protect both cables. The cables shall be interlocked such that the circuit breaker will open when either cable is disconnected.
11. Each ground fault current device shall be provided with a test circuit to test the device at 50 percent or less of the current rating of the grounding resistor and the test circuit shall cause the corresponding circuit interrupting circuit device to open. Each ground fault device shall be driven by a single window current transformer, which shall encircle the load power conductors. The test circuit shall not subject the equipment to an actual phase to phase ground fault.
12. The longwall power center shall be equipped with a primary visible disconnecting device installed to deenergize the primary of the high-voltage power center transformer(s) when the device is open.
13. The longwall power center shall be equipped with a secondary (4,160-volt) disconnecting device installed to deenergize all high-voltage circuits extending to the longwall controller when the device is open.
14. The longwall controller shall be provided with a main visible disconnecting device installed to deenergize all high-voltage circuits extending from the controller.
15. Each disconnecting device shall be installed so that:
a) It can be determined by visual observation that the contacts are opened without removing any cover(s);
b) All load power conductors are grounded when the device is in the “open” position;
c) The device can be locked in the open position; and
A sign shall be located near each disconnecting device that identifies the circuit the device disconnects.
16. The control circuit for the power center shall be interlocked with the primary disconnecting device in the power center so that:
a) When the primary disconnecting device is in the “open” position, the control circuit can only be powered through an auxiliary switch in the “test” position; and
b) When the main disconnecting device is in the “closed” position, the control circuit can be powered only through an auxiliary switch in the “normal” position.
17. The control circuits for high-voltage and other circuits in the longwall controller shall be interlocked with the main disconnecting device such that:
a) When the main disconnecting device is in the open and grounded position, the control circuit can only be powered through an auxiliary switch in the test position (in the “test” position, no voltage greater than 150 volts nominal shall exit the controller);
b) When the main disconnecting device is in the closed position, the control circuit can be powered only through an auxiliary switch in the normal position; and
c) Neither the main circuit breaker nor the main disconnecting device can be closed unless the auxiliary switch is in the “normal” position without dropping out the incoming high-voltage power circuit.
18. The longwall power center and controller shall not be located within 150 feet of the longwall face.
19. Each high-voltage cable installed as part of the longwall mining system shall be type SHD-GC or other similar cable that meets the requirements of 30 CFR 75.804, with a minimum rating of 5,000 volts, and shall have an outer jacket that has been accepted by MSHA as flame-resistant.
20. Each splice or repair in a high-voltage cable shall be made 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 or made with a kit that has been accepted by MSHA as flame-resistant. Kits having tape as the outer jacket are not acceptable.
21. Each splice or repair in a high-voltage cable shall be made only by a qualified person (as provided in 30 CFR §75.153) who has received hands-on training in the proper methods of splicing and repairing high-voltage cables.
22. Cable handling and support systems (for example, Bretby and monorail systems) that are designed, installed, and maintained the high-voltage cables from damage and to minimize the possibility of miners contacting the cables shall be used.
23. High-voltage cables shall be guarded at the following locations:
(a) Where miners regularly work or travel over or under the cables;
(b) Where the cables leave the cable handling and support systems to extend to electric components; and
(c) Where the cables are in the same raceway as low-voltage cables.
The guarding shall protect the cables from damage and shall minimize the possibility of miners contacting the cables. The guarding shall be of grounded metal or reinforced non-conductive flame-resistant material. Additionally, guarding 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, unless deenergized.
24. A means to secure the connection box or in-line connector at the middle of the face shall be installed to provide secure connections of the high-voltage cables.
25. Energized high-voltage cables shall not be handled except when the shearer cable needs to be trained (shearer cable inadvertently coming out of the cable trough). When the shearer cable needs to be trained, high-voltage insulating gloves or high-voltage insulating sticks shall be used for protection against shock hazard. Miners shall not handle the shearer cable if the cable is out of the cable trough, unless the cable has been deenergized or the miner uses high-voltage gloves or a high-voltage insulating stick. Miners shall not handle any other energized high-voltage cable.
26. High-voltage personal protective equipment, including rubber gloves, shall be visually inspected before each use. High-voltage rubber gloves shall be field air tested before each use to ensure their effectiveness. Damaged or defective protective equipment shall be removed from the mine or destroyed. A sufficient storage facility shall be provided for the cable handling equipment. The storage facility location shall be clearly marked to indicate its purpose and examined weekly to assure protective equipment is present. Insulated personal protective equipment shall be rated for a minimum of 7,500 volts and electrically tested every six months in accordance with a nationally recognized standard.
27. Barriers shall be provided and covers shall be arranged so that miners can work in the 4,160-volt section of the power center without being exposed to energized high-voltage conductors or parts, including capacitors, when the disconnect switch is in the "open" and "grounded" position. Miners required to troubleshoot either the high-voltage section of the deenergized power center(s) or longwall controller enclosure shall not be exposed to any energized conductors or parts that exceed 150 volts phase to ground.
28. Barriers shall be provided and covers shall be arranged so that miners can work in the control and communication compartments of the power center or longwall controller enclosure without being exposed to energized conductors or parts that exceed 150 volts phase-to-ground regardless of the position of the appropriate onboard disconnect switch.
29. Barriers shall be provided and covers shall be arranged so that miners can work in the motor contactor compartments of the shearer without being exposed to energized high-voltage conductors or parts, when the shearer input disconnect switch is in the "open" and "grounded" position.
30. Cover interlock switches shall be provided to automatically deenergize the incoming high-voltage circuit to the power center, when any cover that provides access to energized high-voltage conductors or parts is removed.
31. Caution labels shall be installed and maintained on the covers of the compartments of the longwall power center, controller enclosure, and shearer enclosure to warn miners against entering these compartments before deenergizing the incoming power. Also, caution labels shall be installed and maintained on all covers that provide access to high-voltage conductors and parts to warn miners against entering these compartments before all capacitors have been discharged. A means shall be available to ground these capacitors. Also, when low- or medium-voltage equipment can be energized with the input disconnect in the open position, caution labels shall be installed and maintained on the covers of the compartments to warn miners that the input disconnect only deenergizes high-voltage circuits.
32. Before any electrical work (including testing, troubleshooting and faultfinding) is performed on any high-voltage equipment or cable, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the contacts of the proper disconnecting device are "open" and "grounded" or when a cable coupler is used as a disconnecting device, determine that the high-voltage cable is deenergized and disconnected from the power source;
(b) Lockout and tag the disconnect switch or cable coupler in this position;
(c) Assure that capacitors have been discharged and "grounded, and
(d) If a cable coupler is used as the disconnecting device, connect the load power conductors in the high-voltage cable to the grounded frame of the enclosure by means of the grounding receptacle provided and place a dust cover on the enclosure receptacle from which the cable was disconnected.
33. The Petitioner's alternative method shall not be implemented until all personnel who perform maintenance on the longwall have received training in high-voltage safety and maintenance procedures. Thereafter, all replacement maintenance personnel, unless they have received the above training in the previous 12 month period, shall receive the above training prior to performing maintenance work on longwall equipment. Also, all personnel who work in proximity of the high-voltage equipment or who move high-voltage equipment or cables shall be trained in high-voltage safety procedures. Thereafter, all replacement personnel, unless they have received the above training in the previous 12 month period, shall receive high-voltage safety procedures training prior to performing work on the longwall section. A record of this training shall be maintained and made available to authorized MSHA representatives and to miners’ representatives.
34. The high-voltage longwall mining equipment shall be MSHA approved.
35. The high-voltage longwall mining equipment shall not be put into service until after MSHA has inspected the equipment and determined that it is in compliance with all the above terms and conditions. The Petitioner shall notify MSHA before the longwall mining equipment is put into service in any subsequent longwall panel. The notice shall advise MSHA of any modifications to the equipment and provide a reasonable time for MSHA to schedule an inspection of the equipment.
36. Methane monitors shall be installed and maintained on the longwall face in accordance with 30 CFR 75.342.
37. A minimum of 12 Self-Contained Self-Rescuers (SCSR”s) shall be stored in the vicinity of the headgate and a minimum of 12 SCSR’s shall be stored along the face or at the tailgate of the longwall section to meet the requirements of 30 CFR 75.1714.
38. Within 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 training, hazard training, specialized training for qualified persons under 30 CFR 75.153, annual refresher training and the terms and conditions stated in the Proposed Decision and Order.
Any party to this section 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