In the matter of Petition for Modification
The Ohio Valley Coal Company
Powhatan No. 6 Mine
I.D. No. 33-01159 Docket No. M-98-111-C
PROPOSED DECISION AND ORDER
Petitioner’s Powhatan No. 6 Mine, located in Belmont county, Ohio is currently operating under a modification of the application of 30 CFR 75.1002 granted in Docket No. M-87-169-C. The modification was issued on September 14, 1987, and became final on October 26, 1987.
On November 20, 1998, the Petitioner filed a request, Docket No. M97-136-C, to amend Petitioner’s previously granted modification Docket No. M-87-169-C of the application of 30 CFR 75.1002 to Petitioner’s Powhatan No. 6 Mine located in Belmont, County, Ohio. 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 afforded by the standard.
MSHA has modified the terms and conditions contained in the previously granted modification (Docket No. M87-169-C) to include the same protection to miners as is provided in other recent modifications. This Proposed Decision Order, Docket No. M-98-111-C, when final, shall supersede the modification granted for 75.1002 in Docket No. M-87-169-C.
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 was 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, The Ohio Valley Coal Company is granted a modification of the application of 30 CFR 75.1002 to its Powhatan No. 6 Mine.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Coal Mine Safety and Health Act of 1997, 30 U.S.C., sec. 811(c), it is ordered that The Ohio Valley Coal Company’s request for amendment of the application of 30 CFR 75.1002 as granted in Docket No. M-98-111-C in the Powhatan No. 6 Mine is hereby:
GRANTED, conditioned upon compliance with the following special terms and conditions.
1. The nominal voltage of the longwall face conveyors and shearer circuit(s) shall not exceed 4,160 volts.
2. The nominal voltage of the remaining longwall power circuit(s) shall not exceed 995 volts.
3. The nominal voltage of the longwall control circuits shall not exceed 120 volts.
4. Ground-fault current for the 4,1600-volt circuits shall be limited by a neutral grounding resistor to not more than 0.50 ampere or the setting specified in the longwall approval documentation, if less.
5. Each high-voltage conveyor motor 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.
6. The high-voltage circuit(s) shall be provided with a primary back-up 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 0.25 second.
7. The longwall power center shall be provided with a secondary back-up ground-fault protection that shall de-energize the main high-voltage circuit breaker in the longwall power center 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 grounding 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 0.25 second.
8. The high-voltage neutral grounding resistor shall be provided with thermal protection that will de-energize the 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 shall operate at either 50 percent of the maximum temperature rise of the grounding resistor or 150 degrees centigrade, whichever is less. The thermal protection may consist of a current transformer and overcurrent relay in the grounding resistor circuit that will de-energize the incoming high-voltage circuit supplying the power center.
9. Current transformers used to provide ground-fault protection shall be a single window type, which shall encircle the load power conductors.
10. Each high-voltage motor and shearer circuit shall be provided with instantaneous short circuit protection set at not more than the setting specified in the longwall approval documentation or not more than 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 .050 second 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. The circuit interrupting devices for the shearer and the face conveyor motor circuits shall be located in the longwall power center.
11. The 4,160-volt circuit(s) shall be provided with back-up short-circuit protection by means of a high-voltage circuit breaker in the longwall power center. This circuit breaker shall be set at not more than 75 percent of the minimum phase-to-phase short-circuit current available at the longwall controller or the setting specified in the longwall approval documentation, whichever is less. A time delay may be permitted for coordination with downstream short-circuit protection devices. A time delay shall not exceed the setting specified in the longwall approval documentation, or 0.25 second, whichever is less.
12. High-voltage circuits shall be protected against short circuits, oveerloads, ground faults, and undervoltage by circuit interrupting devices of adequate interrupting capacity. Circuit interrupting devices shall not reclose automatically.
13. The longwall power center shall be equipped with a primary visible disconnecting device installed to de-energize the primary of the high-voltage transformer(s) when the device is open. A visible disconnect shall also be provided for control and communications circuits.
14. 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 primary disconnecting device is in the “closed” position, the control circuit can be powered only through an auxiliary switch in the “normal” position.
15. The longwall motor and shearer circuits shall be provided with disconnecting devices and/or cable couplers installed to disconnect each high-voltage cable extending from the power center.
16. The high-voltage shearer may be provided with an optional shearer disconnecting devices installed to disconnect the 4,160 volt motor contactor compartments located on the shearer.
17. Each disconnecting device shall be installed so that:
(a) It can be determined by visual observation that the disconnecting device contacts are open without removing any cover(s);
(b) All high-voltage power conductors can be grounded when the disconnecting device is in the “open” position;
(c) The disconnecting device can be locked in the “open” position; and
(d) If a cable coupler is used as a disconnecting device, connect the phase conductors in the high-voltage cable to a frame common to the enclosure by means of the grounding receptacle provided and place a dust cover on the enclosure receptacle from which the cable was disconnected.
A sign shall be located near each switch identifying the circuits(s) that the device disconnects.
18. Each 4,160-volt cable installed as a 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.
19. Each splice or repair shall be made in a workmanlike manner and in accordance with the instructions of the manufacturer of the splice or repair materials. Each splice or major repair shall be made so that all cable components are replaced with similar components. The high-voltage cable outer jacket shall be vulcanized with flame-resistant material, that has been accepted by MSHA as flame-resistant. Repairs are considered major if there is any damage to the insulation, shielding, or conductors. Kits employing tape as outer jacket shall not be used.
20. Any high-voltage longwall cable with damage to the extent that any metallic component of the cable is displaced or damaged shall be immediately removed from service and repairs shall be made by a qualified person (as provided in 30 CFR 75.153). Splices and repairs in high-voltage cables 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.
21. High-voltage cables shall be guarded at the following locations:
(a) Where miners regularly work or travel over, under or around the cables;
(b) Where the cables leave the cable handling and support systems to extend to electrical components; and
(c) Where 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 nonconductive, flame-resistant material. Additional guarding, unless the high-voltage cable is de-energized, 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.
22. Adequate 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.
23. Cable handling and support systems (for example monorail systems, bretby, etc.) 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.
24. 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 protecting against shock hazards. Miners shall not handle the shearer cable if the cable is out of the cable trough unless the cable has been deenergized. Miners shall not handle any other high-voltage cables.
25. High-voltage personal protective equipment, including rubber gloves, shall be visibly 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 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.
26. 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 primary disconnect switch is in the “open” and “grounded” position.
27. Barriers shall be provided and covers shall be arranged so that miners can work in the control compartment(s) of the power center without being exposed to energized conductors or parts that exceed nominal 120 volts (except for the capacitance tripping circuit) regardless of the position of the primary disconnect switch.
28. Barriers shall be provided and covers shall be arranged so that miners can work in the 4,160-volt section of the shearer without being exposed to energized conductors or parts that exceed 150 volts-to-ground when the input disconnect switch located on the shearer is in the “open” and “grounded” position.
29. Cover interlock switches shall be provided to automatically de-energize the incoming high-voltage circuit to the power center, when any cover that provides access to energized high-voltage conductors or parts, including capacitors, is removed. However, motor junction boxes do not need cover interlocks switches.
30. Cover interlock switches shall be provided to automatically de-energize the incoming high-voltage circuit to the shearer, when any cover that provides access to energized high-voltage conductors or parts is removed. However, motor junction boxes do not need cover interlocks switches.
31. Caution labels shall be installed and maintained on the covers of the compartments of the longwall power center or optional shearer disconnect enclosure containing a primary disconnecting device to warn miners against entering these compartments before de-energizing the incoming power. Also caution labels shall be installed and maintained on all covers that provide access to 4,160-volt conductors and parts to warn miners against entering these compartments before all 4,160-volt capacitors have been discharged. A means shall be provided 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 de-energizes high-voltage circuits.
32. Caution labels shall be installed and maintained on the covers of the longwall shearer containing an optional shearer disconnecting device to warn miners against entering this compartment before deenergizing the incoming power to the shearer. Also caution labels shall be installed and maintained on all covers that provide access to 4,160-volt conductors and parts to warn miners against entering these compartments before opening the shearer disconnect on the shearer.
33. Before any electrical work ( including testing, trouble-shooting and faultfinding ) is performed inside the input high-voltage compartment of the power center, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the contacts of the appropriate outby disconnecting device are “open” and “grounded”;
(b) Lock out and tag the disconnecting device; and
(c) Assure that the capacitors are discharged and “grounded”.
34. Before any electrical work ( including testing, trouble-shooting and faultfinding ) is performed inside the 4,160-volt compartments of the power center, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the contacts of the primary disconnecting device are “open” and “grounded”;
(b) Lock out and tag the disconnecting device; and
(c) Assure that the capacitors are discharged and “grounded”.
35. Before any electrical work ( including testing, trouble-shooting and faultfinding) is performed inside the input high-voltage compartment of the shearer, face conveyor motors or on the high-voltage cables extending from the power center, a qualified person (as provided in 30 CFR 75.153) shall;
(a) Determine at the power center or optional shearer disconnect enclosure, that the contacts of the appropriate disconnecting device are “open” and “grounded”;
(b) Lockout and tag the disconnecting device ;and
(c) Assure that all capacitors have been discharged and “grounded”.
Also, each ungrounded conductor of the high-voltage circuit or cable upon which work is to be performed shall be connected to the system grounding medium.
If a cable coupler is used as the disconnecting device, connect the phase conductors in the high-voltage cable to a frame common to the enclosure by means of the grounding receptacle provided and place a dust cover on the receptacle from which the cable is disconnected.
36. Before any electrical work (including testing, troubleshooting, or faultfinding) is performed inside the contactor or motor compartments for the shearer, a qualified person (as provided in 30 CFR 75.153) shall:
(a) Determine that the contacts of the disconnecting device in the shearer are “open” and “grounded”; and
(b) Lockout and tag the disconnecting device in this position.
37. 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. This training shall be reviewed as part of the employees annual electrical retraining. Also, all personnel who work in the proximity of the high-voltage equipment or who move high-voltage equipment or cables shall be trained in high-voltage safety procedures. A record of this training shall be maintained and made available to authorized MSHA representatives and to other interested parties.
38. The longwall high-voltage mining equipment shall be MSHA approved.
39. The high-voltage longwall mining equipment shall not be put into service until after MHSA has inspected the equipment and determined that it is in compliance with all the above terms and conditions. The Petitioner shall notify MSHA before mining equipment is put into service in any subsequent longwall panel. The notice shall advise MSHA of any modification to the equipment and provide a reasonable time for MSHA to schedule an inspection of the equipment if necessary.
40. Methane monitors shall be installed and maintained on the long wall face in accordance with 30 CFR 75.342.
41. Self-contained self-rescuers (SCSR’s) shall be worn or stored in accordance with the approved plan to meet the requirements of 30 CFR 75.1714.
42. 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 initial and refresher training regarding 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 thirty 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