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Can a 3 Phase RCCB be used if there is no neutral?

Sarth

I know that there are some 3 phase RCCBs that do not have to have a neutral to work however this means that the test button will not work if that is how the test button is configured. So instead of the 3 month manual test sticker that gets put on the enclosure do 3 phase RCCBs need to have a different sticker asking for a 3 month test with an actual RCD tester instead?

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    I believe that there are some TPN RCCBs whose test buttons do work without a N connection - the internal test circuit is just connected between two different Ls instead of L & N and with a higher value resistor to suit the 400V difference.

    Some other manufacturers simply suggest adding a resistor between an otherwise unused N terminal and a particular line (the value being difference between what would be needed for 230V and 400V situations) to allow the conventional L-N test circuit to work.

    So I think the proper answer is to pick a device whose manufacturer does suppose TP(no N) operation - by whatever approach they recommend.

       - Andy.

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    I believe that there are some TPN RCCBs whose test buttons do work without a N connection - the internal test circuit is just connected between two different Ls instead of L & N and with a higher value resistor to suit the 400V difference.

    Some other manufacturers simply suggest adding a resistor between an otherwise unused N terminal and a particular line (the value being difference between what would be needed for 230V and 400V situations) to allow the conventional L-N test circuit to work.

    So I think the proper answer is to pick a device whose manufacturer does suppose TP(no N) operation - by whatever approach they recommend.

       - Andy.

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