DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
ACCIDENT INVESTIGATION REPORT
(Surface Coal Facility)
Fatal Electrical Accident
No.1 Plant (I.d. No. 15-17733)
D-mac Enterprises Inc.
Pikeville, Pike County, Kentucky
July 5, 1999
Mark V. Bartley
Robert M. Bates
Originating Office - Mine Safety and Health Administration
159 North Mayo Trail, Pikeville, Kentucky 41501
Carl E. Boone, II, District Manager
GENERAL INFORMATIONThe No. 1 Plant of D-Mac Enterprises Inc., is located at Lower Johns Creek, seven miles northeast of Pikeville, in Pike County, Kentucky. The principal company officer is Steven Fain, President. The preparation plant is managed and operated by Steven Fain.
The No. 1 Plant consists of a coal preparation facility that is supplied with coal from an adjacent underground mine, No. 2 Mine, Garrett Mining Inc. Coal is belted directly from a slope entry into a coal crushing structure and from there into the coal preparation facility. Clean coal is transported via an overland belt across a state roadway to railroad cars for transportation to customers.
D-Mac Enterprises Inc. is a contract operator for Mapco Coal Inc., which owns the preparation facility and also contracts work at Garrett Mining Inc.
The No. 1 Plant processes 1,000 tons of coal per day and currently employs a total of 12 persons, utilizing one twelve hour production shift and one twelve hour maintenance shift. The plant normally operates five days-per-week.
The last complete health and safety inspection by the Mine Safety and Health Administration of the No. 1 Plant was completed on March 31, 1999.
DESCRIPTION OF ACCIDENT
On Monday, July 5, 1999, at approximately 7:00 a.m., the day shift crew reported to work. Five employees were present at the plant: Steven Fain, President/Superintendent; Vernon Hall, Utility Man/Electrician; Kelly Prater, Plant Operator; James Cline, Sampler; and Daniel McCoy, Dozer Operator. McCoy traveled to the coal stockpile, Prater traveled to the plant control room on the fifth floor, Cline began checking fluids and samples on the third floor, and Hall began checking chemicals on the fifth floor. Fain completed some paperwork and delivered it to the Garrett Mining office located next to the preparation plant. He returned to the plant and walked through it, checking chutes and screens for loose parts and obstructions. After completing this, he returned to the office located outside of the plant structure.
Fred Spears, plant electrician, arrived at the plant site at approximately 10:00 a.m. for the start of his regularly scheduled 10:00 a.m. to 6:00 p.m. shift. Fain spoke with Spears after his arrival and informed him of some inoperative lights in the magnetite room and other maintenance problems. Spears informed Fain he would take care of the problems. Fain proceeded to the fifth floor plant control room. At approximately 10:40 a.m., the heavy medium vessel elevator motor stopped and subsequently the plant began to shut down. Fain called Spears via the plant's loud speaker system and informed him that the washbox had kicked off. Spears said he would be right up.
Prater informed Fain that he would go down to the fourth floor of the plant and check the heavy medium elevator refuse chute because the limit switch on the chute had been damaged on a previous occasion. He went to the plant elevator, which was located on the opposite side of the building, and pushed the call button.
Hall, who had been on the sixth floor when the plant shut down, proceeded to the fifth floor control room. Upon his arrival, Fain told him that the wash box chain had stopped. Hall went down to the fourth floor, using a stairway near the plant control room, and visually checked the limit switch. At this time, no one was at the refuse chute. When Hall observed no apparent damage to the limit switch, he returned to the plant control room and informed Fain that a blown control fuse might be the problem. He obtained a multi meter and went into the master control center (MCC) room where the circuit breaker and control fuse for the heavy medium vessel elevator were located. The MCC room is adjacent to the plant control room and is accessed by traveling through the plant control room.
In the MCC room, Hall checked the two ampere fuse for the control circuit and found that it was blown. Hall replaced the control fuse, re-energized the circuit and discarded the blown fuse. Fain, who had been with Hall while he replaced the fuse, went back to the plant control room. Hall replaced the meter test leads in the meter case and at some point returned to the plant control room.
Prater, upon arriving on the fourth floor, exited the elevator and walked to the heavy medium elevator refuse chute where the limit switch was mounted to the metal frame of the chute. When he arrived Spears was standing on the hand-rails for ease in reaching the limit switch mounting bracket. Spears told Prater to go to the MCC room and de-energize the circuit breaker for the heavy medium vessel elevator circuit before he began to examine the switch. Prater proceeded to the fifth floor plant control room and informed Fain that Spears had requested him to de-energize the circuit breaker. Fain, acknowledged and told him to trip the breaker. Prater then traveled to the MCC room and tripped the circuit breaker for the heavy medium vessel elevator, which also de-energized the 120-volt control circuit that supplied power to the limit switch. Spears, prior to the circuit being de-energized, removed the switch from the mounting bracket on the refuse chute.
The investigation determined that once the limit switch was removed from the metal mounting bracket the switch was ungrounded. This condition existed because the switch was not provided with an internal or external ground wire and the non-metallic liquid-tight conduit isolated the switch from the grounded rigid metal conduit. It was also determined that an electrical fault, due to insulation failure to one of the conductors inside the limit switch, created a shock hazard which elevated the limit switch housing to 130-volts and resulted in Spears receiving a fatal electrical shock.
Prater proceeded back down to the refuse chute on the fourth floor. Upon arrival at the refuse chute, Prater found Spears collapsed and laying against the refuse chute face-forward with the limit switch between Spears's chest and the refuse chute. Prater immediately returned to the fifth floor control room where he informed Hall and Cline that Spears was seriously injured.
Fain, who was in the control room, was informed of the accident and ran to the scene. Prater retrieved a broom-handle to place against Spears to avoid any potential electrical hazard that might still exist in the area. Spears was removed from the access landing and checked for a pulse. No pulse was found. Cardiopulmonary resuscitation (CPR) was started. At 10:53 a.m., Steven Fain called 911 from the preparation plant control room and requested assistance.
Prater, Hall, and Cline continued CPR until Johns Creek Volunteer Fire Department members arrived on the scene and took over CPR. DHP Ambulance Service personnel arrived on the scene and continued CPR while transporting Spears to Pikeville Methodist Hospital where CPR was terminated. Pike County Deputy Coroner Frank Robertson was called to the hospital and pronounced Spears dead at 1:10 p.m.
Unsure of whom to contact on the federally observed "4th of July holiday (observed on July 5, 1999) Fain called his health and safety consultant, Claude Stamper. Claude Stamper of Stamper Technical Services informed MSHA and the Kentucky Department of Mines and Minerals of the accident. A joint investigation began on July 5, 1999.
The investigation revealed the following factors relevant to the occurrence of the accident:
- There were no eyewitnesses to the accident.
- The victim was a certified electrician.
- The temperature in the preparation plant at the time of the accident was approximately 95
- The victim and his clothing were wet from washing down the second floor of the
preparation plant just prior to the accident.
- The victim was not wearing gloves at the time of the accident.
- The victim was found face down, with his feet and legs located between the middle and
top rail of the access platform. His torso was on the inclined refuse chute.
- No pulse was found after the accident.
- Results from the Office of the Associate Chief Medical Examiner's office indicate that
the immediate cause of death was electrocution.
- A monthly examination of the electrical system had been conducted by Fred Spears on
June 28, 1999 and June 30, 1999. Notes by Spears indicated that he had replaced the
limit switch. Testimony revealed that the limit switch had been damaged by contract
workers at the plant on June 27, 1999.
- The circuit breaker for the heavy medium vessel elevator was not locked out and tagged
before the limit switch was removed from the refuse chute.
- Evidence indicates that the victim made contact with the energized frame of the
ungrounded limit switch.
- The 34" section of liquid-tight conduit extending from the rigid metal conduit and
terminating at the limit switch did not contain internal metal reinforcement.
- No internal or external grounding conductor was installed to bond the frame of the limit switch to the rigid metal conduit.
- Prior to the accident, the limit switch was attached to a metal mounting bracket on the
refuse chute using two bolts with nuts. The mounting holes on the limit switch were
non-threaded and were covered with gray paint.
- One side of the 120-volt (nominal) control transformer supplying power to the control
circuit for the heavy medium vessel elevator was attached to ground in the MCC room.
The ungrounded side of the control circuit was protected by a 2 ampere, ATM-2 fuse.
The rigid metal conduit system serves as the grounding conductor for the limit switch.
- The limit switch involved in the accident was designed for use in wet locations.
However, when the cover was removed during the investigation, the interior of the
switch and the terminal connections were wet.
- A coupling in the rigid metal conduit system above the limit switch was not properly
maintained. One of the openings was not plugged, and black electrical tape was wrapped
around the exterior to cover the opening. This condition could possibly have admitted
water into the conduit system and ultimately into the limit switch.
- When the circuit was re-energized during the investigation, a potential of 130 volts was measured between the exposed metal parts of the limit switch and the frame of the refuse
chute. The voltage readings were not affected by moving or rotating the limit switch.
- The control circuit conductors inside the limit switch were damaged in two locations.
One of the damaged areas was located near the top of the limit switch and was in contact
with the metal housing. The insulation was worn to the extent that the copper
conductors were visible. Also, the insulation was discolored in the damaged areas,
indicating that a ground fault had occurred previously. The two-ampere control fuse that
Vernon Hall removed shortly before the accident, was checked and found to be blown.
- The 480 -volt motor circuits in the plant are supplied by a three-phase, ungrounded delta system. In these circuits, a short section of flexible metal conduit is installed between the rigid metal conduit and the motor to allow for vibration. The motor frame is then bonded to the rigid metal conduit system or a structural member of the preparation plant by a separate grounding conductor. The only exception to this is on the ground floor, where a solid copper conductor bonds the motor frame to the ground field under the preparation plant. The ground field and the plant structural members are connected to the utility system ground.
The accident occurred because electrical work was performed on an improperly grounded limit switch before the circuit was de-energized, locked out, and suitably tagged.
1. A 103 (k) order (No. 4014091) was issued on July 5, 1999, to D-Mac Enterprises Inc. The order was issued to ensure the safety of the miners working in the area and to ensure that the area was not disturbed so that an investigation could be conducted.
2. A 104 (d)(1) citation (No. 7352793) was issued on July 7, 1999, to D-Mac Enterprises Inc. for violation of 30 CFR, Part 77.501. The circuit breaker for the heavy medium vessel elevator circuit was not locked out and tagged prior to work being performed on the 120 volt (nominal) limit switch. The electrician performing the work dispatched another employee, who was not a certified electrician, to de-energize the circuit breaker while he began performing work on the switch. The plant owner/superintendent was present at the circuit breaker location and was aware that the non-certified person was going to de-energize the circuit as instructed by the certified electrician.
3. A 104 (a) citation (No. 7352794) was issued on July 7, 1999, to D-Mac Enterprises Inc. for violation of 30 CFR, Part 77.502. A potentially hazardous condition was present during an electrical examination of the limit switch on the heavy medium elevator refuse chute on 6/28/1999. The metallic frame of the limit switch was not provided with a proper frame ground. Although the condition existed at the time of the examination, it was not corrected.
4. A 104 (a) citation (No. 7352795) was issued on July 7, 1999, to D-Mac Enterprises Inc., for violation of 30 CFR, Part 77.701. The metallic frame of the limit switch for the heavy medium vessel elevator refuse chute was not provided with a proper frame ground. A 34 inch section of liquid-tight flexible non-metallic conduit containing the 120 volt control circuit conductors leading to the switch was not provided with an internal or external grounding conductor.
5. A 104 (a) Citation (No. 7352796) was issued on July 7, 1999, to D-Mac Enterprises Inc., for violation of 30 CFR, Part 77.516. The citation was issued for failure to maintain the limit switch for the heavy medium vessel refuse chute and the conduit system connected to the switch in an approved manner for the location of installation. The switch and the conduit system were not maintained properly because water was found inside of the switch. A coupling in the rigid metal conduit system above the switch was installed in a manner that allowed water into the conduit system and subsequently into the switch.
Mark V. Bartley
Electrical Engineer/Accident Investigator
Robert M. Bates
Carl E. Boone, II
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