Electrical

MNM Fatality – 7/9/20

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On July 9, 2020, a mine superintendent was electrocuted while attempting to reverse the polarity of a 4,160 VAC circuit by switching the leads inside an energized 4,160 VAC enclosure that contained a vacuum circuit breaker and disconnect.

Best Practices: 

  • Follow these steps before performing electrical work inside a high voltage enclosure:
    1. Locate the high voltage visual disconnect away from the enclosure that supplies incoming electrical power to the enclosure.
    2. Open the visual disconnect to provide visual evidence that the incoming power cable(s) or conductors have been de-energized.
    3. Lock-out and tag-out the visual disconnect yourself. Never rely on others to do this for you.
    4. Ground the de-energized conductors.
  • Verify circuits are de-energized using properly rated electrical meters and non-contact voltage testers.
  • Ensure properly qualified miners perform all work on high voltage equipment.
  • Wear properly rated and well maintained personal protective equipment, including arc flash protection such as a hood, gloves, shirt and pants.
  • Train miners on safe work practices for high voltage electrical equipment and circuits.

Additional Information: 

This is the 11th fatality reported in 2020, and the first classified as “electrical.”

Click here for: Preliminary Report (pdf), Final Report (pdf).

2019 Fatality #20 / Coal #10

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On September 17, 2019, an electrician was electrocuted when he contacted an energized conductor. The victim contacted a 995 VAC connector while attempting to troubleshoot the scrubber motor circuit on a continuous mining machine.

Best Practices: 

  • Lock out and tag out the electrical circuit yourself. Never rely on others to do this for you.
  • BEFORE performing electrical work:
    • Open the circuit breaker or load break switch away from the enclosure to de-energize the incoming power cables or conductors.
    • Open the visual disconnect away from the enclosure to confirm that the incoming power cables or conductors have been de-energized.
    • Lock out and tag out the visual disconnect.
    • Ground the de-energized phase conductors.
  • Wear properly rated and well maintained electrical gloves when troubleshooting or testing energized circuits.  After the electrical problem has been found, follow the proper steps before performing electrical work.
  • Use properly rated electrical meters and non-contact voltage testers to ensure electrical circuits have been de-energized.
  • Only use qualified, trained workers. Ensure electrical work is performed by a qualified electrician or someone trained to do electrical work under a qualified electrician’s direct supervision.
  • Identify circuits and circuit breakers. Properly identify all electrical circuits and circuit breakers before troubleshooting or performing electrical work.

Click here for: MSHA Preliminary Report (pdf), Final Report (pdf).

2019 Fatality #16 / MNM #10

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On Friday August 15, 2019, a 44-year-old contract electrician with 10 weeks of mining experience was electrocuted when he contacted a 120V cable while working inside a fire suppression system’s electrical panel.

Best Practices: 

  • Ensure miners receive proper training on all electrical related tasks. 
  • Ensure that circuit breakers and switches are properly labeled.
  • Properly lock-out and tag-out electrical circuits prior to working on them.
  • Wear properly rated and well maintained personal protective equipment while troubleshooting or testing energized circuits. 
  • Use properly insulated tools when performing electrical work.
  • Use properly rated electrical meters and non-contact voltage testers to ensure electrical circuits have been de-energized prior to performing electrical work. 

Click here for: MSHA Preliminary Report (pdf), Final Report (pdf).

2019 Fatality #15 / Coal #6

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On Wednesday, August 7, 2019, a 42-year-old preparation plant electrician with 15 years of mining experience was electrocuted when he contacted an energized connection of a 4,160 VAC electrical circuit. The victim was in the plant’s Motor Control Center (MCC) adjusting the linkage between the disconnect lever and the internal components of the 4,160 VAC panel supplying power to the plant feed belt motors.

Best Practices: 

  • Lock Out and Tag Out the electrical circuit yourself and NEVER rely on others to do this for you.
  • Control Hazardous Energy!  Design and arrange MCCs so electrical equipment can be serviced without hazards.  Install and maintain a main disconnecting means located at a readily accessible point capable of disconnecting all ungrounded conductors from the circuit to safely service the equipment.
  • Install warning labels on line side terminals of circuit breakers and switches indicating that the terminal lugs remain energized when the circuit breaker or switch is open.
  • Before performing troubleshooting or electrical type work, develop a plan, communicate and discuss the plan with qualified electricians to ensure the task can be completed without creating hazardous situations.
  • Follow these steps BEFORE entering an electrical enclosure or performing electrical work: (1) Locate the circuit breaker or load break switch away from the enclosure and open it to de-energize the incoming power cable(s) or conductors. (2) Locate the visual disconnect away from the enclosure and open it to provide visual evidence that the incoming power cable(s) or conductors have been de-energized. (3) Lock-out and tag-out the visual disconnect. (4) Ground the de-energized conductors.
  • Wear properly rated and maintained electrical gloves when troubleshooting or testing energized circuits.
  • Focus on the task at hand and ensure safe work practices to complete the service.  A second qualified electrician should double check to ensure you have followed all necessary safety precautions.
  • Use properly rated electrical meters and non-contact voltage testers to ensure electrical circuits have been de-energized.

Click here for: MSHA Preliminary Report (pdf), Final Report (pdf).

Fatality #2 for Coal 2018

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On Wednesday, February 21, 2018, a 38-year-old highwall mining machine operator, with 21 years of total mining experience, was electrocuted when he contacted an energized connection of a 7,200 volt electrical circuit.  The victim was found inside a transformer station troubleshooting and/or performing electrical work on the electrical system that supplies power to the mining machine.

Best Practices: 
  • Lock-Out and Tag-Out the electrical circuit yourself and NEVER rely on others to do this for you.
  • Follow these steps BEFORE entering an electrical enclosure or performing electrical work:
    1. Locate the circuit breaker or load break switch away from the enclosure and open it to de-energize the incoming power cable(s) or conductors.
    2. Locate the visual disconnect away from the enclosure and open it to provide visual evidence that the incoming power cable(s) or conductors have been de-energized.
    3. Lock-out and tag-out the visual disconnect.
    4. Ground the de-energized conductors.
  • Wear properly rated and well maintained electrical gloves when troubleshooting or testing energized circuits.  After the electrical problem has been found, follow the proper steps before performing electrical work
  • Use properly rated electrical meters and non-contact voltage testers to ensure electrical circuits have been de-energized.
  • Install warning labels on line side terminals of circuit breakers and switches stating that the terminal lugs remain energized when the circuit breaker or switch is open.
  • ​Electrical work must be performed by a qualified electrician or someone trained to do electrical work under the direct supervision of a qualified electrician.

Click here for: MSHA Preliminary Report (pdf), Final Report (pdf).

Fatality #5 for Metal/Nonmetal Mining 2017

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On July 14, 2017, a part time mine employee was moving irrigation pipe by hand and was electrocuted when the pipe came in contact with high voltage transmission lines overhead.

Best Practices

  • Before work begins, conduct a hazard assessment and examine the work area to identify and correct hazards and ensure safe distances to overhead power lines.
  • Contact the electrical utility to determine the operating voltage of the line and confirm the safe limits of approach distances.
  • Do not use electrically conductive tools or materials in situations where they may contact overhead power lines.

Click here for: MSHA Preliminary Report (pdf), Final Report (pdf).

Fatality #4 for Metal/Nonmetal Mining 2016

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m04On April 9, 2016, a 25-year old plant operator with 4 years of mining experience was fatally injured at a surface copper ore mine. He was found unresponsive, kneeling with his face against a stainless steel flange that was connected to a high-density polyethylene pipe. The victim appeared to have received an electrical shock.

Best Practices

  • Establish and discuss safe work procedures that include hazard analysis before beginning work. Identify and control all hazards associated with the work to be performed and use methods to properly protect persons.
  • Train all persons to understand the hazards associated with working near energized electrical conductors.
  • Use properly rated Personal Protective Equipment (PPE) including Arc Flash Protection such as a hood, gloves, shirt, and pants.
  • Ensure that all electrical systems are safely designed and properly installed and that all metal enclosing or encasing electrical circuits are grounded or provided with equivalent protection.
  • Provide equipment grounding conductors, with a sufficiently low impedance to limit the voltage to ground, for metal enclosures.  Use a properly rated meter to identify any stray electrical currents which may be present.
  • Lock Out, Tag Out, and Try: Place your lock and tag on the disconnecting device and test for power.

Click here for: MSHA Preliminary Report (pdf), MSHA Investigation Report (pdf), Overview (pdf).

Fatality #9 for Coal Mining 2014

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ftl2014c09On Wednesday, August 20, 2014, a 41-year-old maintenance supervisor with approximately 19 years of mining experience was killed when he came in contact with an energized component inside an explosion proof enclosure.  The victim had removed the enclosure’s panel cover and was troubleshooting or performing electrical work on the 600 VAC roof bolting machine when he was electrocuted.

Best Practices
  • Wear properly rated and well maintained electrical gloves when troubleshooting or testing energized circuits.
  • REMEMBER, troubleshooting or testing is the work of locating electrical problems and verifying that proper repairs have been made.
  • After locating the electrical problem, and before performing electrical work, open the circuit breaker, and disconnect and lock-out and tag-out the visual disconnecting device.
  • Use properly rated electrical meters and non-contact voltage testers to ensure electrical circuits are deenergized prior to performing electrical work.
  • REMEMBER, electrical work is the work required to install or maintain electrical equipment or conductors.
  • Perform your own lock-out and tag-out procedure and NEVER rely on others to do this for you.
  • Install warning labels on a circuit breaker’s line side terminals stating that the terminal lugs remain energized when the circuit breaker is open.
  • Develop, communicate, and execute a written plan before performing electrical troubleshooting and repair to ensure that safety is maximized for all miners involved in the task.

Click here for: MSHA Preliminary Report (pdf), MSHA Investigation Report (pdf).

Fatality #15 for Metal/Nonmetal Mining 2014

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ftl2014m15On July 21, 2014, a 28-year-old assistant plant manager with 11 years of mining experience was killed at a sand and gravel dredge operation.  He was riding in an aluminum boat that became stuck in low water on top of 480 volt energized power conductors.  The victim was electrocuted when he exited the boat, attempting to pull slack on the power conductors.

Best Practices

  • Establish and discuss safe work procedures before beginning work. Identify and control all hazards associated with the work to be performed and use methods to properly protect persons.
  • Train all persons to understand the hazards associated with working near energized electrical conductors.
  • De-energize power and ensure that the circuit is visibly open before working near energized conductors that may have damaged insulation.
  • Lock and Tag! Place YOUR lock and tag on the disconnecting device.
  • Use properly rated Personal Protective Equipment (PPE) including Arc Flash Protection such as a hood, gloves, shirt, and pants.
  • Ensure electrical conductors are properly rated and designed for the applications used.
  • Ensure that ground fault protection is provided to protect persons
  • Ensure that all electrical systems are safely designed and properly installed.

Click here for: MSHA Preliminary Report (pdf)

Fatality #18 for Metal/Nonmetal Mining 2013

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ftl2013m18On November 18, 2013, a 33-year old contract electrician foreman with 14 years of experience was injured at a crushed stone mine. The victim was working in a 480-volt electrical enclosure, pulling cable for a new pump that was being installed, when he contacted energized conductors. He was transported to a hospital where he died on November 22, 2013.

Best Practices

  • Ensure that persons are trained on all electrical tests and safety equipment necessary to safely test and ground the circuit where work is to be performed.
  • Positively identify the circuit on which work is to be conducted.
  • De-energize power and ensure that the circuit is visibly open for circuits being worked on and circuits near the work area.
  • Lock and Tag! Place YOUR lock and tag on the disconnecting device.
  • Use properly rated Personal Protective Equipment (PPE) including Arc Flash Protection such as a hood, gloves, shirt, and pants.
  • Ensure ALL electrical components in the enclosure are de-energized by testing for voltage using properly rated test equipment.
  • Install warning labels on the terminal covers of bottom feed circuit breakers warning that “Bottom terminal lugs remain energized when the circuit breaker is open.”

Click here for: MSHA Preliminary Report (pdf), MSHA Investigation Report (pdf), Overview (powerpoint), Overview (pdf).