The RCD tripping when earth core touched - advice?

[KevA]

Hi,

I have been connected some two-way switches for an passageway light. After isolating the circuit started working on the new wiring for the switches, touched the earth core of the lighting cable on the supply side (disconnected) and the Consumer Unit RCD protecting all the circuits tripped. I haven't carried out any testing yet for the Minor Electrical Installation Works Certificate, but does anyone have a quick heads up on a possible cause?

Cheers.

 

[Deleted member 9648]

If the neutral and earth for that circuit is connected in the DB you will get a N-E fault from the live,through a lamp or control gear and to neutral.

 

[J Sabo]

This caught me out when i didnt fully understand RCD protection.

My mate ask me to hard wire his compressor in his garage and i isolated the supply. When cutting the cable, it tripped the RCD (neutral-earth fault). Bit puzzling at first

 

[SirKit Breaker]

Hi,

I have been connected some two-way switches for an passageway light. After isolating the circuit started working on the new wiring for the switches, touched the earth core of the lighting cable on the supply side (disconnected) and the Consumer Unit RCD protecting all the circuits tripped. I haven't carried out any testing yet for the Minor Electrical Installation Works Certificate, but does anyone have a quick heads up on a possible cause?

Cheers.

Its quite normal, used to catch me out as well.