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Any requirements to have pressure test 3.5KV 1 min on 600/1000V BS 6724 cable in field?

Kwok Lo

I know the similar requirements for LV cable manufacturers and LV switchboard in field. But never heard to test on new installed cable. 
Is there any risk to have breakdown?

  • +1

    I am not aware of any requirement  for 3.5 KV testing of 600/1000 volt cables under UK wiring regulations. I have installed loads and never once tested at more than 1000 volts.

    Requirements overseas may differ, and one should comply with any such requirements. Some clients or consulting engineers may require a test at 3.5 KV and if the person paying for the work wants this then it must be done.

    If the cable is of good quality and correctly installed there should be no question of breakdown at that voltage.

  • 0 in reply to broadgage

    Thank you for your precious experience. I also think 99.9% will not cause breakdown. For the employer point of view they are no harm to have such test. But if the breakdown happens, who responsible to the replacement.

    I think each regulation will have lot of people experience on it. It is strange to specify the cause that nobody have it before. Too many uncertainty outcome will happen.

  • 0

    no harm to have such test

    As I recall, for some appliances a 3.5kV test is used at manufacture stage, but is NOT recommended for in-service testing, since the higher voltage can stress the insulation to the point of risking permanent damage if it's repeated too often. 500V is far more usual for on-site testing. I'd suspect there may be a similar argument for cables - but others here will have better definite knowledge.

           - Andy.

  • 0

    Are you being asked to test an LV (400V ) cable  at 3.5kV after it has been installed ? It would be unusual, and is more of a test of whatever is connected to the ends and the quality of terminations than the cable itself. Great care would be needed to ensure that there was nothing already connected that was not going to track over or flash  over.

    I'd suggest that there needs to be a very special situation that needs this,  and I cannot think of one right now,  and normally it is both  unnecessary and unwise.

    I'd also check that whoever wants the test done is happy to pay for any repair that might be needed should it cause damage.

    Mike

  • 0 in reply to mapj1

    I agree with you, one specify the requirement never think about the consequences .

  • 0 in reply to AJJewsbury

    thank you Andy

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