A plant electrician was electrocuted when he contacted an energised connection of a 4,160 VAC electrical circuit, says the Mine Safety and Health Administration (MSHA).
The 42-year-old 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 energised 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:
- Locate the circuit breaker or load break switch away from the enclosure and open it to de-energise the incoming power cable(s) or conductors.
- 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-energised.
- Lock-out and tag-out the visual disconnect.
- Ground the de-energised conductors.
- Wear properly rated and maintained electrical gloves when troubleshooting or testing energised 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-energised.
