The Mine Safety and Health Administration (MSHA) recently released a fatality alert about an accident that occurred in early August, resulting in the electrocution of a 42-year-old plant electrician. The victim, who had 15 years of mining experience, was electrocuted when he contacted an energized connection of a 4,160VAC electrical circuit. According to the report, the man was in the plant’s motor control center (MCC) adjusting the linkage between the disconnect lever and the internal components of the 4,160VAC panel supplying power to the plant feed belt motors.
MSHA offers the following best practices to help prevent similar tragedies:
• Lock out and tag out the electrical circuit yourself; 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 deenergize 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.
Of the 14 MSHA fatality reported issued in 2019, this is the first electrical accident classification. As of this date in 2018, there were 12 MSHA fatalities reported.