20 bay modular building split into 3 sections via swa to 3ph+n busbar trunking, tapoff box to sub-board in each bay.
one swa was feeding trunking that in turn was feeding 7 sub-boards.
got a call, some of the lights (grid lights on a suspended ceiling) were flashing like a disco hall and some werent working at all.
got there and a full bay of lights werent working and sure enough 4 of 5 lights were lik a disco hall.
went to the 1st sub-board and the mcb feeding the non working lights was in the on position?
pressed the rcd and then all the lights in the bays after this one starting flashing like a disco hall.
isolated the trunking and inspected.
turns out the socket feeding the trunking had not been installed properly and the neutral was only just making.
never seen anything like it before, shame i didnt have my phone with me otherwise i would of videoed it.
got me 2 days work inspecting every connection on the trunking and replacing the half dozen motion detectors and light fittings that had fried.