An engine room crew member was investigating problems with the fuel oil circulating pump at the circuit breaker board. The pump’s breaker was opened and he proceeded to check the isolation status of the breaker terminals with a multimeter.
As soon as he touched the terminals with multimeter leads, a huge spark emanated from the breaker/multimeter, with a loud explosive sound and black smoke.
The victim sustained burns on his face, neck and hands due to radiant heat. He was given first aid and signed off from the vessel for further medical attention ashore. The investigation found that he had attempted to check the voltage across breaker terminals with the multimeter selector knob at the Resistance (1 Ohm) setting instead of the Voltage (1000VAC) setting. The electric charge found its shortest path (through the multimeter), which then exploded. It was also found that the victim had failed to use insulating gloves which would have decreased the severity of the injury.
Lessons learned
- Approved insulated gloves should be used while working on electrical components.
- It is always a good idea to cross-verify your tool and workplace before starting the job;
- Is the guard in place?
- Is the setting correct?
- Is the electrical supply safe?
- Is the lighting adequate?
Reference: nautinst.org