Electrical isolation: Failing to “prove dead” at the point of work
- Safety Flash
- Published on 16 May 2025
- Generated on 9 October 2026
- IMCA SF 09/25
- 2 minute read
One of our members discovered that some personnel and worksites were not following the intent of their own company electrical isolation protocols.
What happened?
The principle of “proving dead” when working on electrical equipment, was not being followed at the point of work, at some worksites.
It was discovered some worksites are not proving dead at the point of work, only at the point of isolation, which can often be remote from the intended point of work. This increases the risk of serious injury or fatality due to potential errors occurring between the point of isolation and the intended workplace, and result in personnel inadvertently approaching an active system.
Example 1:
Isolating a vessel thruster (#6) at the main High Voltage (HV) switchboard. Proving dead at the switchboard and earthing at the switchboard, an engineer then goes to the point of work but does not “prove dead” the equipment to be worked upon. The engineer intended to go to thruster 6, but in fact went to thruster 7. Result: direct access and contact with live terminals.
Example 2:
An ROV technician isolated the port Remotely Operated Vehicle (ROV) at the Power Distribution Unit (PDU) and applied an earthing spider at the HV termination box. ROV technician then started work on the starboard ROV. Result: direct access and contact with live terminals.
Lesson learned
· Crew members may inadvertently expose themselves to risk by failing to follow “proving dead” protocols at the point of work. Both of these events could easily have lead to serious injury or death.
· Take the time to prove equipment dead at the worksite, at the actual point of work.
Members may wish to refer to
Related Safety Flashes
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IMCA SF 11/23
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IMCA SF 15/18
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IMCA SF 12/20
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