Ring Main Fault

[MarkieSparkie]

No sympathy for OP from me, this circuit should have been dead tested before energising it. Particularly as this is newly plastered location, energising before proving IR is sound is just plain stupid. Sorry, but you reap what sow. If you cut corners on the inspection and testing, don't be surprised if you experience trouble when the circuit is energised.

 

[Amp David]

I always thought an RCD detected an imbalance between the line and neutral conductors, not line/neutral and CPC.

 

[marino546]

if its just been plastered the dampness could trip the rcd