I am trying to isolate a circuit to move a socket in a floorbox. The MCBs at the consumer unit are labelled up but there are I have a choice of four to choose from for the circuit I need to isolate.
Now of course one could ordinarily just flick all switches one by one until I hit the right one and then remove the cartridge from the board to be certain that it's dead. Problem is, however, that one of the circuits powers a server and if I take it out I would not be very popular.
I tried using a socket tester with an RCD trip tester but the it won't trip. Silly question perhaps but are these trip testers likely to trip the MCB first or the RCD?
In any case the trip tester is not tripping anything, I've used two testers, one is telling me that there is a fault with the earth volts (fault >50v) and another just reports a fault no trip.
I'm using the plug-in type, are they any good for this? And is there any other safe way of determining which circuit I need to isolate at the board without just switching it all off?
Cheers for any advice,