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Electrical shock – Failure of isolations and barriers

A crew member was testing 240V cables as part of re-terminating a replacement motor. There was some isolation in place, with equipment partly out of the racks for testing by a separate crew. However, the electrical supply for a space heater was unknowingly not covered by the existing isolation in the test position. Crew member received an electrical shock whilst removing insulation from a still active 240V conductor.

What went wrong:

  • Specific equipment drawing was not utilised for isolation – a generic motor drawing was used instead. Isolation integrity had not been individually assessed for different activities.

It is important to ensure that Permit to Work (PTW) and lock out/tag out procedures specify the requirement to reference equipment-specific rather than generic drawings, prior to determining the appropriate isolation.

Safety Event

Published: 2 October 2015
Download: IMCA SF 14/15

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