Rcd's that fail to operate in less than 40 m/s

[Richard Burns]

If your trip tests were done with no external loads on the circuit then they do reveal the RCD is faulty and replacing it should resolve the symptoms.
However there should not normally be leakage up to 15mA on a circuit in a house so it may be worth checking that your IR results for the protected circuit are not significantly low, it is probably a minor peak in current since it is intermittent but worth checking the circuit is not damaged.

 

[HandySparks]

I agree that the RCBO shouldn't be tripping at 15mA. However, it might be instructive to do a ramp test on it with no loads attached.

 

[James123456]

Hi Richard,
All other test results were as expected Until I got the the rcd times it didn't trip at 0 degrees but did at 180 repeated the test 3 times at 1/2 as I didn't quite believe it any reason the rcbo wld be overactive just one way? This is the only thing that really bothered me in just putting it solely down to a faulty rcbo, although nothing was operating I didn't disconnect all loads I must admit