RCD tripping on a light circuit

[kippyken88]

I think I am correct, that those Wylex MCB's, only isolate the live, in which case, if the RCD trips, only when that MCB is turned on, irrespective of whether the light switch for the circuit is on, or off - that suggest to me, there is leakage between L and E, before the switch.

For the OP - As a final check, if you locate and isolate the L, which feeds to switch for the six lights, safely isolate it with a connector, switch back on and the RCD still trips - It suggests the fault is on the cable between the consumer unit, and the switch.

If the cable goes up, to the ceiling, before making it's way across to the switch, then the chances are, that a floor nail or similar has damaged the cable.

Hi Harry,

That is the only thing I have done as suggested earlier, disconnected the live brown on the switch, closed the breaker and the the RCD still trips.
So I'm looking at a cable fault between switch and breaker?

I'm pretty sure, though not 100% that the cable will run under the floor which is going to be a nightmare.

Time for some pro help methinks.

 

[SUNRAY]

Hi Harry,

That is the only thing I have done as suggested earlier, disconnected the live brown on the switch, closed the breaker and the the RCD still trips.
So I'm looking at a cable fault between switch and breaker?

The cable from the breaker goes to some junction box, the cable at the switch also goes to that junction box.

If you are lucky it may be near one of the lights.

I'm pretty sure, though not 100% that the cable will run under the floor which is going to be a nightmare.

However there may be a junction box by most of the lights

Time for some pro help methinks.

I think so too