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Fatal Incident - Safe Isolation failure?

jbrameld

What do we think on this incident, reported a bit differently in these two locations:

Whilst very sad and no-one should lose their life in the workplace (or anywhere else) I can't help thinking that an engineer of 30 years' experience should have been familiar with safe isolation procedures, and perhaps these were not followed.  There are of course many unreported possibilities such as multiple supply sources not identified but if you follow the mantra of poking a verified test device probe in before anything else (like your fingers or a screwdriver….), then your chances of falling victim are much reduced.

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    The two pole tester beats the non-contact volt stick for proving dead.

    When I was taught safe isolation twenty years ago we were taught to prove live before proving dead, so:

    • Prove the circuit LIVE using the two pole tester, checking L-N, L-E and N-E to ensure correct polarity, also the two pole tester works correctly
    • Isolate the circuit and secure it.
    • Prove the circuit DEAD using the two pole tester, checking L-N, L-E and N-E.
    • Prove the tester still works using a known live supply, such as the incoming terminals of the isolation switch or a proving unit.

    That way there’s less risk of testing between two conductors or terminals both with the same voltage on them or between a live and a disconnected conductor and not identifying an issue. 

    The “up to date” method omits proving live and goes straight to isolation then proving dead, to reduce the risk of  electric shock, but it means the circuit hasn’t been proved healthy to start off with, increasing the risk of not identifying problems.

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  • 0

    The two pole tester beats the non-contact volt stick for proving dead.

    When I was taught safe isolation twenty years ago we were taught to prove live before proving dead, so:

    • Prove the circuit LIVE using the two pole tester, checking L-N, L-E and N-E to ensure correct polarity, also the two pole tester works correctly
    • Isolate the circuit and secure it.
    • Prove the circuit DEAD using the two pole tester, checking L-N, L-E and N-E.
    • Prove the tester still works using a known live supply, such as the incoming terminals of the isolation switch or a proving unit.

    That way there’s less risk of testing between two conductors or terminals both with the same voltage on them or between a live and a disconnected conductor and not identifying an issue. 

    The “up to date” method omits proving live and goes straight to isolation then proving dead, to reduce the risk of  electric shock, but it means the circuit hasn’t been proved healthy to start off with, increasing the risk of not identifying problems.

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