In the matter of Petition for Modification
Mountain Coal Company
West Elk Mine
I.D. No. 05-03672 Docket No. M-1999-002-C
PROPOSED DECISION AND ORDER
On January 4, 1999, a petition was filed seeking a modification of the application of 30 CFR 75.901(a) to the West Elk Mine, located in Gunnison County, Colorado. The Petitioner alleges that the proposed alternative method will at all times guarantee no less than the same measure of protection afforded the miners under 30 CFR 75.901(a).
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. The investigation report included a short circuit analysis conducted by MSHA at the West Elk Mine. On April 19, 1999, Mountain Coal Company filed a short circuit analysis on the proposed generators to be used at the Petitioner's mine. On August 10, 1999, Mountain Coal Company filed comments on MSHA's investigative report requesting that nine (9) stipulations be changed and the removal of one (1) stipulation contained in the investigative report.
After a careful review of the entire record, including the petition, MSHA's investigative report and recommendations, comments from Mountain Coal Company and short circuit analysis, 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 75.901(a).
On the basis of the petition and the findings of MSHA's investigation, Mountain Coal Company, is granted a modification of the application of 30 CFR 75.901(a) in the West Elk Mine.
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 Mountain Coal Company's Petition for Modification of the application of 30 CFR 75.901(a) to the West Elk Mine is hereby:
GRANTED, for the 480-volt, three-phase, 460 KW Diesel Powered Generator (DPG) sets supplying power to a 400 KVA three-phase transformer and three-phase 480-, 575-, and 995-volt power circuits, conditioned upon compliance with the following terms and conditions:
1. The 460 KW, 480-volt, diesel powered generator sets with an approved diesel engine shall only be used to move equipment in and out of the mine and, when necessary, to supply temporary power for short duration for other outby equipment, such as pumps.
2. The sum of all motors operated from the diesel powered generator set at one time shall not exceed 400 horsepower.
3. The neutral of the wye configured 480-volt, 575-volt and 995-volt autotransformer shall have in series between it and the frame of the generator unit, a 995-volt rated resistor that will limit the maximum phase- to-frame fault current to 0.5 ampere continuously.
4. The 480-volt, 575-volt and 995-volt output circuits shall each be equipped with an instantaneous ground fault relay that will cause their respective circuit breaker(s) to trip when a phase-to-frame fault occurs. The ground-fault protection shall be set at not more than 0.090 ampere.
5. The 480-volt output circuit of the generator shall be equipped with a backup sensitive ground fault relay that will cause the circuit breaker that supplies power to the autotransformer to trip and shut down the diesel engine when a phase-to-frame fault occurs. The ground-fault protection shall be set at not more than
0.090 ampere. A time delay may be permitted for coordination with ground-fault protection of the autotransformer output branch circuits. 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 seconds.
6. The 995-volt circuit breaker shall be provided with a means to provide short-circuit, overcurrent, grounded- phase, undervoltage and ground monitoring protection. The protection for the 995-volt portable equipment cables shall be provided by a 225 or 400 maximum ampere rating circuit breaker, that is equipped with the instantaneous only trip unit (settings for the instantaneous only trip unit shall be limited to between 500 and 1000 amperes) that provides the specified protection for the portable cable attached to the circuit breaker. The instantaneous only trip unit for the 995-volt circuit breaker shall be adjusted to trip at 70 percent of the maximum available short circuit current at the point where the portable cable enters the equipment or the maximum allowable instantaneous settings specified in 30 CFR 75.601-1, whichever is less.
7. The 575-volt circuit breaker(s) shall be provided with a means to provide short-circuit, overcurrent, grounded-phase, undervoltage and ground monitoring protection. The protection for the 575-volt portable equipment cables shall be provided by a 225 or 400 maximum ampere rating circuit breaker, that is equipped with the instantaneous only trip unit (settings for the instantaneous only trip unit shall be limited to between 300 and 1000 amperes) that provides the specified protection for the portable cable attached to the circuit breaker. The instantaneous only trip unit for the 575-volt circuit breaker shall be adjusted to trip at 70 percent of the maximum available short circuit current at the point where the portable cable enters the equipment or the maximum allowable instantaneous settings specified in 30 CFR 75.601-1, whichever is less.
8. The 480-volt circuit breaker shall be provided with a means to provide short-circuit, overcurrent, grounded- phase, undervoltage and ground monitoring protection. The protection for the 480-volt portable equipment cables shall be provided by a 225 or 400 maximum ampere rating circuit breaker, that is equipped with an instantaneous only trip unit (settings for the instantaneous only trip unit shall be limited to between 500 and 1500 amperes). The instantaneous only trip unit for the 480-volt circuit breaker shall be adjusted to trip at 70 percent of the maximum available short circuit current at the point where the portable cable enters the equipment or the maximum allowable instantaneous settings specified in 30 CFR 75.601-1, whichever is less.
9. When the generator set is used, to move equipment or perform work in areas outby the section loading point where equipment is not required to be maintained permissible, the equipment portable cable length(s) shall not exceed the length(s) specified in 30 CFR Part 18, Table 9 or Petition for Modification, Docket No. M-96-104-C.
10. Permanent label(s)showing the maximum circuit breaker setting(s) and maximum portable cable length(s) shall be installed on each instantaneous trip unit or be maintained near each 480-volt, 575-volt and 995-volt circuit breaker. The permanent label(s) shall be maintained legible.
11. When the generator set is used to move equipment or perform work in areas outby the section loading point where equipment is not required to be maintained permissible, the grounding system shall include a MSHA accepted ground wire monitor system, or other no less effective device approved by the District Manager to assure ground continuity between the frame of the generator and the equipment being moved or used.
12. The 995-volt portable cable(s) that extend from the generator to mobile equipment shall be type SHD- GC with a minimum of 2,000-volt rating, and shall have an outer jacket that has been accepted by MSHA as flame-resistant. All other portable cables used to supply power to low voltage equipment shall have a minimum of 2,000-volt rating and shall have an outer jacket that has been accepted by MSHA as flame- resistant.
13. A strain relief device shall be provided on each end of the cable(s) that extends between the generator and the piece of mobile equipment being powered.
14. Prior to moving each piece of equipment or performing work in areas outby the section loading point where the equipment is not required to be maintained permissible, and upon start-up of the diesel generator, a functional test of each ground fault and ground wire monitor system shall be performed by a qualified electrician who meets the requirements of 30 CFR 75.153. A record showing the results of these tests shall be kept.
15. The diesel generator system shall not be operated until after MSHA has inspected the equipment and determined that it is in compliance with all the above terms and conditions, and all applicable requirements of 30 CFR Part 75.
16. The diesel generator system, when in use, shall comply with all other applicable requirements of the Federal Mine Safety and Health Act of 1977 and the applicable requirements of 30 CFR, Part 75.
17. Prior to using the diesel generator system, training shall be conducted for all qualified persons on the proper examination and test procedures to be utilized. The training shall be "hands on" specific, and shall be incorporated into the Part 48 training plan.
18. 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, at any of the listed mines, to the Coal Mine Safety and Health District Manager. These proposed revisions shall specify the following:
a) The "hands on" specific training specified in Condition No. 17;
b) Initial training regarding the terms and conditions stated in the Proposed Decision and Order; and
c) Training in the hazards of setting short circuit interrupting device(s) too high to adequately protect the 480-volt, 575-volt and 995-volt portable cables.
The approval procedures as specified in 30 CFR 48.3 for proposed revisions to already approved training plans shall apply.
Any party to this action desiring a hearing on this matter must file in accordance with 30 CFR 44.14, as amended, (Federal Register 53430, December 28, 1990) 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 desire 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.
Michael J. Lawless
Deputy Administrator
for Coal Mine Safety and Health