RCD Test failure question

[Julie.]

Without the details, its difficult to say for sure, but on face value both rcds need to be replaced, it's a matter of isolating, removing the existing and installing new then testing, £200 doesn't sound too far out if there is two, but still depends on the make.

However since both have failed, this may suggest a common fault, either in testing or the wiring itself in which case it may require investigation.

 

[davesparks]

Not that I can remember, but we did have an issue with the shower, so that might explain that... the rest just doesn’t tally does it?

The change of the shower MCB may well be related to the issue you had with the shower and that is the likely answer to that one.

The failure of an RCD is unusual, for two to fail the same is very very unusual. I would be testing for other faults which can prevent RCDs from tripping before just replacing them. Otherwise you may end up with 2 brand new RCDs not tripping.

 

[telectrix]

possible N-E fault??? as i said in post #13

 

[davesparks]

Fair one Dave, I’ve never had one fail on me so wasn’t aware that’s what the meter would display. Every days a school day. ?

I've never had one fail, but I have set the tester to 30mA whne testing a 100mA RCD by mistake more than once.