by , on February 11, 2011

A contract apprentice electrician died  and two co-workers were seriously injured in an arc flash that occurred while they were performing maintenance work on an electrical circuit breaker at a Martin Marietta Materials surface granite mine. The circuit breaker that they were working on was in the “OFF” position but remained energized on the input side.  MSHA has determined that the accident occurred because contractor management procedures failed to ensure that the electrical circuit breaker was de-energized prior to performing work on it.

Click here to read more about MSHA investigation of Arc Flash Incident


Hugh Hoagland
About author:
Hugh Hoagland is the foremost tester of clothing and PPE exposed to electrical arcs and is an arc flash expert. Read more about Hugh.

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