AMSJ » Linkage adjustment on disconnect lever in MCC kills electrician
Electrical Safety LATEST NEWS Plant Maintenance

Linkage adjustment on disconnect lever in MCC kills electrician

Linkage adjustment in MCC motor control centre
A simple linkage adjustment has claimed the life of an electrician

The US Based Mine Safety and Health Administration (MSHA) has issued a Fatality Alert after an electrician was electrocuted during a linkage adjustment on a lever in a live panel at Blackhawk Mining LLC’s South Hollow Prep Plant and Loadout in Kanawha County, W.Va.

MSHA said that 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.

MSHA has provided the following Best Practices to help prevent this type of accident:

  • 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:
    • 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.
    • 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.
    • Lock-out and tag-out the visual disconnect.
    • 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.

This is the 14th fatality reported in US Mines during 2019 and the 1st Electrical accident classification fatality.

Australian mines are reminded that the conduct of live electrical work is likely prohibited in most states.

Read more Mining Safety News

Add Comment

Click here to post a comment

AMSJ Winter 2020