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:
- Locate the high voltage visual disconnect away from the enclosure that supplies incoming electrical power to the enclosure.
- Open the visual disconnect to provide visual evidence that the incoming power cable(s) or conductors have been de-energized.
- Lock-out and tag-out the visual disconnect yourself. Never rely on others to do this for you.
- 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).