In the matter of Petition for Modification
Bowie Resources Limited
Bowie No. 3 Mine
I.D. No. 05-04758 Docket No. M-2003-081-C
PROPOSED DECISION AND ORDER
On October21, 2003, a petition was filed seekinga modification of the application of 30 CFR 75.1002 to Petitioner’s BowieNo. 3 Mine, locatedin Delta County,Colorado. The modification being sought is for a high-voltage continuous miner previously granted amodification of the same standardat the company’s Bowie #2 Mineunder Docket No. M-2003-023-C, issuedSeptember 3, 2003,and finalized October 3, 2003. The Petitioner allegesthat the alternative methodoutlined in the petition will at all times guarantee no less than the same measureof protection affordedby the standard.
MSHA personnelconducted an investigation of the petitionand filed a report of their findings and recommendations with the Administrator for Coal Mine Safetyand Health. After a careful review of the entire record,including the petition, 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 guaranteeno less than the same measureof protection affordedthe miners under30 CFR 75.1002.
MSHA’s investigation confirmed that the high-voltage continuous miner and electrical components proposed for use at the No. 3 Mineare the same machinery previously investigated at the No. 2 Mine.
On the basis of the petitionand the findingsof MSHA’s investigation, Bowie Resources Limitedis granted a modification of the application of 30 CFR 75.1002to its Bowie No. 3 Mine.
When this Proposed Decisionand order becomesfinal it will supercede and fully replacethe modification grantedunder Docket No. M-2003-023-C, issued September 3, 2003.
ORDER
Wherefore, pursuantto 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 Safetyand Health Act of 1977, 30 U.S.C., Sec. 811(c), it is orderedthat Bowie Resources Limited’sPetition for Modification of the application of 30 CFR 75.1002 in the Bowie No. 3 Mine is hereby:
GRANTED, for the use of the 2400-volt high-voltage continuous miner(s) at the Bowie No. 3 Mine, conditioned upon compliance with the following terms and conditions:
1. The nominalvoltage of power circuits must not exceed 2400 volts.
2. The nominalvoltage of the control circuitsmust not exceed 120-volts.
3. Each output circuitfrom the power center must be equipped with an MSHA approvedground-wire monitoring system. Each receptacle must be interlocked with the ground-wire monitor circuit such that the circuit-interrupting device will open when the trailing cable is disconnected from the power center receptacle.
4. The trailing cableextending to the high-voltage continuous mining machine must be protected againstshort-circuits, overloads, ground-faults, and undervoltage by a circuit interrupting device of adequateinterrupting capacity as follows:
(a) Trailing cable protection.
(1) Short-circuit protection.
(i) The currentsetting must be either the setting specified in the approval documentation or 75 percent of the minimum available phase-to-phase short-circuit current, whichever is less.
(ii) The time-delay setting of the short-circuit protective device must be eitherthe setting specified in approval documentation or 0.05 second, whicheveris less.
(2) Ground-fault protection.
(i) The ground-fault current must be limitedby a neutral grounding resistor to not more than
0.5 ampere.
(ii) A ground-fault device must causede- energization of the circuit at not more than
0.125 ampere. The time-delay setting of the device must not exceed 0.050second.
(iii)A look-ahead circuit must detecta ground condition and prevent the circuit interrupting device from closing.
(iv) A backup ground-fault device must cause deenergization of the circuitat not more than 40 percentof the voltage developed across the neutral grounding resistor when a ground-fault occurs with the neutral grounding resistor open. The time delay setting of the backupdevice must not exceed
0.25 second.
(v) Athermal device must detect a sustained ground-fault current in the neutralgrounding resistor and deenergize the incoming power. The device must operateat either 50 percent of the maximum temperature rise of the grounding resistor, or 1500C (3020F),
whichever is less. The thermal protection must not be dependent upon control power and may consist of a currenttransformer and overcurrent relayin the grounding resistor circuit.
(vi) A single window-type currenttransformer that encircles all three-phase conductors must be used to activate the ground-fault current device specified in (a)(2)(ii). The equipment groundingconductor(s) must not passthrough the currenttransformer.
(vii)A test circuit for the ground-fault device specified in (a)(2)(ii) must inject no more than 50 percent of the current ratingof the neutral grounding resistor through the current transformer. When the test circuit is activated, the circuit-interrupting device must open.
(3) Undervoltage protection.
(i) The undervoltage device must operate on a loss of voltage, deenergize the circuit, and prevent the equipment from automatically restarting.
(b) Circuit-interrupting devicesmust not reclose automatically.
(c) If a ground-fault indicator light is providedon a high-voltage continuous mining machine and it indicates a grounded phase, the following procedures must be implemented:
(1) The continuous mining machine must be moved immediately to a locationwith a properly supported roof; and
(2) The ground-fault must be locatedand corrected prior to placing the continuous miningmachine back into operation.
(d) All components that provide short-circuit protection must have an interruption ratingin accordance with maximum short-circuit currents available inby that circuit interrupting device(s), and must be rated for the maximum phase-to-phase voltage of the circuit.
(e) Installation and guardingof trailing cables.
(1) Trailing cableinstallation.
The portionof the high-voltage trailing cable from the power centerto the following locations must be either supportedon insulators or located in an unused entry which is barricaded from vehicular travel and provided with warning signs:
(i)The last open crosscut duringadvance mining;
(ii) Within 150 feet of the workingplace during retreat or second mining;or
(iii) Up to 150 feet of the continuous mining machine when the machineis used in outby areas to cut overcasts, underpasses, sumps; to clean rock falls, and for other similar functions.
(2) Temporary storage.
Item (4)(e)does not precludethe temporary lacing ofcable into a sled or a crosscut. The sled or crosscut used for this purpose must be barricaded against vehicular or foot travel and equipped with high-voltage warning signs.
(3) Guarding.
The high-voltage trailing cable must be guardedin the following locationsusing grounded metal or nonconductive flame-resistant material:
(i) Between the power centerand the first cable insulator, if supported, or where the cable enters the used entry;
(ii) From the entrance gland for a minimum distance of 10 feet outbythe last strain clamp on the continuous mining machine; and
(iii) At any location where the trailingcable may be damagedby moving equipment.
(4) Suspended cable or cablecrossover.
When equipmentmust cross any portion of the high voltage trailing cable, the cable must be either:
(i)Suspended from the mine roof; or
(ii) Protected by a cable crossover with the following characteristics:
a. Have a minimum length of 33 inches;
b. Have a minimum width of 17 inches;
c. Have a minimum height of 3 inches;
d. Have a cable placementarea that is a minimum of two and one half inches(2½”) high by four and one quarterinches (4 1/4") wide;
e. Use nonconductive material for the crossover;
f. Use materialfor the crossover that is colored a highly distinctive color. The color black shallnot be used; and
g. The materialfor the crossovers shall have a minimumtensile strength of 6400 pounds per square inch.
5. Trailing cable design.
The high-voltage trailing cable must be designedas follows:
(a) The high-voltage trailing cable must have 100 percent semi-conductor tape shieldingand metallic braid shielding coverage over each insulated power conductor;
(b) The protective jacket must consistof two layers, an outer and inner protective jacket;
(c) The color black must not be used for either of the two protective insulation layers;
(d) The innermost layer of the two layeredinsulation jackets must be colored a distinctive color from the outerjacket to allow easy recognition of damaged areas tothe outer protective jacket insulation;
(e) Be MSHA accepted as flame-resistant under part 18 or approved under subpartk of part 7; and
(f) Meet eitherthe requirements of 75.804 or be a type SHD cablewith a center ground-check conductornot smaller than No. 16 A.W.G.stranded conductor.
6. Trailing cable handlingand pulling.
(a) Miners must not handlethe energized trailingcable unless they are wearing properlytested and rated insulating gloves as specified in Item # 11. If mitts, hooks, tongs, slings, aprons, or other personal protective equipment are used to handle energized cables, high-voltage insulating gloves must be used in conjunction to provide protection against shock hazards.
(b) The trailingcable must be deenergized prior to being pulled by any equipmentother than the continuous mining machine.
7. Splicing and repairof cables.
Splices and repairs to high-voltage trailingcables must comply with the following:
(a) Be made only by a qualifiedperson as providedin 30 CFR 75.153 who has received hands-ontraining in the proper methods of splicingand repairing thesehigh voltage trailing cables;
(b) Be made in a workman-like mannerand in accordance with the instructions of the manufacturer of the repair materials;
(c) Be made in accordance with 30 CFR 75.810. The outer jacket of each spliceor repair shall be vulcanized with flame-resistant material or made with a kit that has been accepted by MSHA as flame-resistant. Each splice or major repairshall be made so that all cable components are replaced with similar components. Repairs are considered majorif there is any damageto the metallic shielding, semi-conductor tape, inner conductor insulation, or conductors. Minor repairs to the outer cable jacket may be made by using tape accepted by MSHA as flame-resistant;
(d) Permanent tape-type splices in any high-voltage trailing cable are prohibited. Only MSHA approved high-voltage splice kits containing outer jacket repairs and splices will be acceptable; and
(e) Splicing of the high-voltage trailing cable within35 feet of the continuous mineris prohibited.
8. Power centers.
(a) The power center(s) supplyingpower to the high-voltage continuous mining machineshall be equippedwith a main disconnecting device installedto deenergize the primary of all transformers when the deviceis in the open position.
(b) All compartments that provide access to energized high voltage conductors or parts must have the following:
(1) Barriers and covers that prevent minersfrom contacting high-voltage conductors or parts.
(2) A cautionlabel(s) to warn miners againstentering the compartment(s) before de-energizing the incoming high-voltage circuits.
(c) The powercenter must also be equippedwith a disconnecting devicethat deenergizes the trailing cable when the device is in the open position.
(d) Each disconnecting device must be designed and installed as follows:
(1) Rated for the maximumphase-to-phase voltage of thecircuit in which they are installed;
(2) Rated for the full-loadcurrent of the circuit that is supplied power throughthe device;
(3) It can be determined by visual observation that the contacts are open withoutremoving any cover;
(4) Marked to clearly identifythe circuit it disconnects;
(5) Grounds all power conductors on the load side when thedevice is in the “open”position;
(6) Can be locked in the “open”position; and,
(7) Capable of interrupting the full-load currentof the circuit, or designed to cause automatic deenergization of the currentprior to openingthe disconnecting device.
(e) The controlcircuit must be interlocked with the main disconnecting device in the power centerso that:
(1) When the primary disconnecting device is in the “open” position, the control circuitcan only be powered through an auxiliaryswitch in the test position; and
(2) When the primary disconnecting device is in the “closed” position, the control circuitcan be powered only through an auxiliary switchin the normal position.
(f) Each cover or removable barrier providing accessto energized high-voltage conductors or parts must be equipped with at least two interlock switches. Removal of any of these covers must automatically deenergize the incoming high-voltage to the power center.
(g) The power center must be equippedwith an emergency stop switch that deenergizes the incoming high-voltage in the event of an emergency.
(h) The power center must be equippedwith a grounding stick to discharge the high-voltage capacitors and circuits. The power centermust have a label readily identifying the location of the groundingstick. The grounding stick must be storedin a dry location.
9. Electrical work; troubleshooting and testing.
(a) Electrical work on all circuits associated with high-voltage continuous mining machines must be performed only by persons qualifiedunder 30 CFR 75.153.
(b) Prior to performing electrical work on the high-voltage trailing cable and the continuous mining machine, except for trouble shootingand testing, the energized circuits and equipment as providedfor in item (e) of thissection, a qualified person must
(1) Open the circuitdisconnecting device;
(2) Disconnect the cable coupler;and
(3) Connect the cable couplerto a grounding receptacle.
(i) A dust cover must be used on the receptacle from which the cable was disconnected.
(ii) When troubleshooting, the deenergized
high-voltage cablemay be disconnected from the groundingreceptacle only for that period oftime necessary to locate and determine the faultcondition. The high-voltage cable must be reconnected to the grounding receptacle prior to work being performedto correct the defective condition.
(4) Lockout the cable couplerwith a padlock. When more than one qualified personis performing work, each person must installan individual padlock; and
(5) Tag the cable couplerto identify the circuit on which work is being performed. When more than one person is performing work, each personmust tag the coupler.
(c) Prior to performing electrical work on the power center containing high-voltage components and parts, except for troubleshooting and testingof energized circuits and equipment as providedfor in item (e) of this section, a qualified person must:
(1) Open the main disconnecting device;
(2) Verify that the contactsof the main disconnecting device are grounded;
(3) Lockout the disconnecting device with a padlock. When more than one qualified person is performing work, each person must install an individual padlock;
(4) Tag the disconnecting device to identify the circuit on which work is being performed. When more than one qualified personis performing work, each person must tag the disconnecting device; and
(5) Discharge all high-voltage capacitors before any workis performed inside any compartment of the power center.
(d) Each padlockand tag must be removedonly by the person who installedthem, except that, if that person is unavailable at the mine, the lock and tag may be removed by a person authorized by the mine operator, provided:
(1) The authorized person is qualified under item (a) ofthis section; and
(2) The operatorensures that the person who installed the lock and tag is aware of the removalbefore that person resumeswork on the affected circuit or equipment.
(e) Before troubleshooting and testing a low-or medium-voltage circuit contained in an enclosurewith exposed high-voltage conductors or parts, the high-voltage circuit must be de-energized, grounded,locked-out, and tagged in accordance with items (b) or (c) of this section, whichever is applicable. Troubleshooting and testing energized circuits must be performed only:
(1) On low- and medium-voltage circuits;
(2) To determinevoltages and currents;and
(3) By personsqualified to performelectrical work under Paragraph(a) of this section and who wear protective gloves in accordance with the following
|
CIRCUIT VOLTAGE |
TYPE OF GLOVE REQUIRED |
|
Greater than 120• |
|
|
volts (nominal) (not intrinsically safe) |
Rubber insulating gloves with leather protectors |
|
40-volts to 120• volts (nominal) (both intrinsically safe and non-intrinsically safe) |
Either rubber insulating gloves with leather protectors or dry work gloves |
|
Greater than 120• volts (nominal) (intrinsically safe) |
Either rubber insulating gloves with leather protectors or dry work gloves |
10. Frequency of examination; recordkeeping.
(a) At least once every 7 days, a person qualified in accordance with 30 CFR 75.153 must test and examine high-voltage continuous mining machines to determine that electrical protection, equipment grounding, permissibility, cable insulation, and control devices are being properly installed and maintained.
(b) At least once every 7 days, a person qualified in accordance with 30 CFR 75.153 must activate the groundfault test circuit required in Item 4(a)(2)(vii) to verify that it will cause the corresponding circuit interrupting device to open.
(c) At least once every 7 days, a person qualified in accordance with 30 CFR 75.153 must examine and test each high-voltage continuous mining machine ground-wire monitor circuit to verify that it will cause the corresponding circuit-interrupting device to open.
(d) Trailing cable must be inspected as follows:
(1) Once each day, a person qualified in accordance with 30 CFR 75.153must inspect the entire length ofthe deenergized high-voltage trailing cable from the power center to the continuous mining machine. The inspection must includethe outer jacket repairs,all splices, and areas where guarding is required.
(2) At the beginning of each production shift, a responsible persondesignated by the mine operator must visually inspect for damage the outer jacket of the de-energized high-voltage trailing cable from the last open crosscut to the continuous mining machine.
(e) If the continuous miningmachine is equippedwith a grounded-phase detectioncircuit, the test circuit must beactivated at the start of each production shift to ensure that the detectioncircuit is functioning properly.
(f) When examinations or tests of equipment described in items (a) through(e) of this section reveala potential fire, electrical shock, ignition, or operational hazard, the equipment must be immediately removed from service until such condition(s) is corrected.
(g) Record of tests.
At the completion of examinations and tests required under items (a), (b), and (c) of this section, the person conducting such examinations and tests must certify by signature and date that they have been conducted. A record must be made of any unsafe condition found and any corrective action taken. Certifications and recordsmust be kept for at least one year and must be made available for inspection by authorized representatives of the Secretary and representatives of miners.
11. High-voltage insulating gloves must:
(a) Have a voltage ratingof at least Class 1 (7500- volts) that meets or exceedsASTM F496-02a, “Standard Specification for In-Service Care of Insulating Gloves and Sleeves” (2002);
(b) Be air tested (rubbergloves only) at the beginning of each shift to ensure their effectiveness;
(c) Be visuallyexamined before each use for signs of damageor defects;
(d) Be removedfrom the underground area of the mine or destroyed when damaged or defective; and,
(e) Be electrically tested every 30 days in accordance with publication ASTM F496-02a.
12. Tramming continuous mining machines into and out of the mine,and from sectionto section.
(a) When trammingthe continuous miningmachine into and outof the mine, and from section to section, one of the power sources specified in item (c) of this section must be used. Additionally, the followingrequirements apply:
(1) Tramming must not occurin areas where permissible equipment is required;
(2) The continuous mining machine must not be used for mining or cutting purposes;
(3) Low-, medium-,or high-voltage cablesmust comply with 30 CFR 75.600-1, 75.907, and 75.826, respectively;
(4) The energized high-voltage cable must be mechanically secured on-boardthe continuous mining machine. This provision applies only to Paragraphs (c)(3), (c)(4),and (c)(5) of this section.
(b) Prior to movingthe continuous miningmachine
(1) the power sourcesspecified in Paragraph (c) of this sectionmust pass a functional test of the ground-fault and ground-wire monitorcircuits. The tests must be performed by a qualified electrician who meets the requirements of 30 CFR 75.153. A record of each test must be maintained and made available to authorized representatives of the Secretary and representatives of the miners; and
(2) the test circuit for the grounded-phase detection circuit on the continuous miningmachine, if applicable, must be activated to ensure a grounded-phase condition does not exist.
(c) The followingalternative sources of electrical power may be utilized to energize the tram motors,essential hydraulic systems and machine controlsfor the purpose of tramming the continuous miner into, out of or around the mine if they meet the requirements set forth below:
(1) Portable transformer that supplies power to the 995-volt tramming motors may be used when the traction transformer and the control transformer on the continuous minerare reconnected to operate at 995-volts. The controlcircuit must not be used to back-feed the 2400-voltcircuits on the continuous miner. The portable transformer shall not operate 2400-voltmotors. When used, the portable transformer shall provideall of the electrical protective featuresand devices required of a sectionpower center. The portable transformer used to powerthe continuous miner for tramming must not be moved when energized; or
(2) A temporary onboardtransformer that steps up the voltage to 2400-volts may be used when the temporary onboard transformer meets the requirements specified above in Nos. 1 through4, 10 through 13, 21 through28, 30 and 31. The temporary transformer must comply with the following:
(i) The inputtrailing cable to the transformer must supply either low or mediumvoltage and comply with the applicable sections of 30 CFR 75;
(ii) The transformer enclosure must be connected to the incoming ground-wire of the low-or medium-voltage trailingcable and be bonded to the frame of the continuous miningmachine by a No. 1/0 or larger A.W.G.grounding conductor. The metallic shell of the cable coupler must be grounded to the frame of the continuous mining machine;
(iii) The transformer must be securely mountedon• board the continuous mining machine and installed to minimize vibration; and
(iv) Be equippedwith cover switchesand an emergency stop switch to remove inputpower.
13. All electrical protective equipment used to handleenergized high-voltage trailing cablesshall be providedby the mine operator.
14. The petitioner’s alternative method shall not be implemented until all personnel who perform maintenance on the high• voltage continuous miner systemhave received trainingin high-voltage safety, testingand maintenance procedures. Also, all personnel who work in proximity of the high-voltage equipment or who move high-voltage equipment or cables shall be trainedin high-voltage safetyprocedures. The training shall be “handson” specific, and shall be incorporated into the Part 48 trainingplan and in the annual refresher trainingplan for the mine. A recordof this training shall be maintained and made available to authorized MSHA representatives and to other interested parties.
15. The high-voltage continuous mining systemshall not be put into service until after MSHA has inspectedthe equipment and determined that it is in compliance with all the above terms and conditions.
16. Within 60 days after this ProposedDecision and Order becomes final, the Petitioner shall submit proposed revisions for its approved30 CFR Part 48 TrainingPlan to the Coal Mine Safetyand Health DistrictManager. These proposed revisions shallinclude, but are not limitedto, task training, hazard training, specialized training for qualified personsunder 30 CFR 75.153, and annual refresher training. In additionthe following shallbe adopted:
(a) Safety precautions for the handlingand use of high• voltage trailingcables, for all miners assignedto work in the area of the high-voltage trailing cable; and
(b) Specialized trainingfor qualified electricians that will be requiredto repair, maintainand/or trouble• shoot the high-voltage trailingcable or equipment. This training shall focus on the requirements of this modification.
Any partyto this actiondesiring a hearingon this mattermust file in accordance with 30 CFR 44.14, within30 days. The request for hearing must be filed with the Administrator for Coal Mine Safety and Health, 1100 Wilson Boulevard, Arlington, Virginia 22209-3939. If a hearing is requested, the request shall contain a concise summaryof position on the issuesof fact or law desired to be raisedby the party requesting the hearing, including specific objections to the proposeddecision. A party other than Petitioner who has requesteda hearing shall also comment upon all issues of fact or law presented in the petition, and any party to this actionrequesting a hearingmay indicate a desired hearing site.
If no request for a hearingis filed within30 days after service thereof, the Decision and Order will become finaland must be posted by the operatoron the mine bulletin boardat the mine.
When this Decision and order becomesfinal it will supercede and fullyreplace the modification granted under Docket No. M-2003-023-C, issued September 3, 2003.
Deputy Administrator
for Coal Mine Safetyand Health