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Electrical problem. My extractor fan keeps on tripping my RCD whenever i turn it on. Answered

I recently installed an Xpelair XX150T exractor fan in my bathroom. This model has an intergrated timer (which i do not want to use so i didn't connect up the unswitched live) and is supposed to be run off of a 3 pole fan switch.
From my distribution board the cables are going to a switch and from there to the 3 pole fan switch and on to the fan. At the distribution board the live is connected into a 20Amp breaker and the neutral is connected to the main neutral bar.
Whenever i switch on the fan the RCD trips. I've checked my wiring and i cant see any reason for this.



Best Answer 8 years ago

Did you do the wiring yourself or have you used existing wiring?

If you did the wiring yourself you may have connected the live wire to an RCD protected feed, and then connected the neutral to the main neutral bar instead of the RCD protected neutral, or vice versa.
This would cause the RCD to trip as soon as the fan switch was turned on.
If you can't locate a seperate RCD protected neutral bar, check the neutral terminal on the RCD. If it has multiple neutral wires connected, this would serve as the protected neutral.
Both wires need to be either protected or not protected or there will be an imbalance that will cause the RCD to trip.

( I also sent this answer as a private message, as I was having trouble posting comments last night).

Hope this helps.


8 years ago

Does the wiring work without the fan connected?
Otherwise, if it's wired-up right have a go at returning it as "defective" - replace with a different product.



8 years ago

You've checked that you haven't confused neutral and ground, right?


Answer 8 years ago

.  That's my first guess. Then I'd check my wiring, particularly at the switches, for shorts.
.  If you have a non-RCD (that's GFI or GFCI on the left side of the Atlantic - it may help to include that in your title), try it and see what happens. If it doesn't trip, ork is probably right. If it trips, you have a short. Do NOT leave the non-RCD breaker in service - for testing only.