Oven tripping RCD when turning off

Lee · 2017-02-10T17:14:27+00:00

Please no arguments about why it's on an RCD protected circuit, I can't easily/practically change that at the moment*. It turns on (it's a fancy one with a SMPSU and LCD display) and if no heating functions are selected it can be turned off again with no issues. If a heating mode is selected it will heat up but if it's then turned OFF it will trip the RCD. It will, rarely, also trip when the control board/thermostat turns off the elements, but mostly it's when it's switched off. It's passing 2mA to ground when it's on (guessing that's the class Y cap in the PSU) but my meter isn't quick enough to catch the fault current. I've measured the elements with a Megger (with them disconnected) and they all check out fine cold and hot so now open to suggestions... It has umpteen relays on the control board is it possible one of them could be arcing and upsetting the RCD? *If it is the RCD at fault it will require changing the CU, as it's obsolete :(

Feb 10, 2017 23 Replies

Rate this thread:

Graham. 9 years ago

Might if they were wired in parallel, but these are effectively in series.

Vote

Lee 9 years ago

Indeed :)

Vote

Lee 9 years ago

Oh dear the label seems to have fallen off the cutout and they must have forgotten to seal it ;) :)

Oven is now on a NON-RCD mcb, we will have to see how that goes. If it exhibits a definite failure then I will probably repair it and put it back on an RCBO.

Vote

Lee 9 years ago

Now it's no longer on an RCD I may well try that - not that it will tell me which one of the umpteen* on the control board that it is.

*Ok there are only 10, but I don't fancy replacing all of them just because ;)

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required