ABSTRACT
It is rare these days for residual current device (RCD) to cause nuisance tripping. An RCD will only trip on a fault between live conductors and earth. If a circuit neutral is connected wrongly, and a load is connected to the circuit, the RCD will detect more current in the neutral than the line conductor, as the neutral conductor and line conductor pass through it and trip. On the rare occasion when the RCD does not trip it may mean that more than one circuit is involved. Starting with the circuit breaker nearest to the one that electricians have switched on, they need to switch the circuit breakers on one at a time until the RCD trips. If the RCD does not reset with all of the lights off, electricians must carry out a visual check on everything, paying particular attention to anything that is outside and could have moisture in.
