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I have a consumer unit in the house that feeds sockets and lights. When I plug the AV500 in to a socket off this unit, it all works.
I also have a sub-main that is located in a separate building and if I plug in to a socket off this consumer unit, I can't connect to the main unit that is in the house.
Both consumer units are fed from the same incoming main, the only difference is the sub main is paralleled off the main feed and is not connected via the house RCD, but one in the CU in separate building.
Earth is good and continuous across both.
I can't figure out why there should be a difference.
Any ideas please ?
Thanks in advance
Bill