I was watching one of the SparkNinja videos recently on (I think) earthing and bonding and in the related chat they mentioned doing an inspection on a caravan park and almost half of the 100 or so RCDs had failed. Two years later when they went back for another inspection (and the owner had been doing regular testing with the built-in test button) it was around 10% that had failed.
I was quite surprised by this and wondered if they were a duff batch, duff brand, or maybe that is really the real-world expectation
Related to this was my curiosity in the Best Practice Guide #4 for coding faults giving a C2 for an RCD self-test failure but only for one in a TT system:
Q1) When you do inspections and test what sort of RCD failure rate do you see?
Q2) How do you code an RCD trip test failure?
I was quite surprised by this and wondered if they were a duff batch, duff brand, or maybe that is really the real-world expectation
Related to this was my curiosity in the Best Practice Guide #4 for coding faults giving a C2 for an RCD self-test failure but only for one in a TT system:
- The main RCD or voltage-operated earth leakage circuit-breaker on a TT system fails to operate when tested with an instrument or integral test button
Q1) When you do inspections and test what sort of RCD failure rate do you see?
Q2) How do you code an RCD trip test failure?