OP
Deleted member 9648
Yep, I agree with Will, the reason I asked if low voltage or mains voltage was because if they had been low voltage, the transformer would have come into play and may have been faulty, but as they are mains this does not apply.
How old is your wiring?
It's the RCD tripping, as transformers are generally class 11 how are they going to trip the RCD?