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RCB Tripping

Posted by Paul , on Sat 20 Feb 2016 01:38pm

Can you help me please? Can an RCB fitted in my junction box (MCB) trip if there is NO current going through it? I have an electric shower and the mains was on as the light was showing on shower. I turned the power off by turning off the fuse on the MCB. The light went out. I then took the wires out as I am removing the shower. I then made a clean cut with wire cutters through the cable causing the RCB to trip. Why did that happen?

Russell Baron

Sun 21 Feb 2016 10:28pm

Hi Paul. Just following on from what Cony says If your not planning to use the shower from now either remove all conductors (L N +E ) from the consumer unit and tape up the ends. Turning off the mcb is not sufficent. If you dont want to do this make sure the cable going to the shower is either put in a junction box or removed from the outgoing side of the shower switch. Thanks Russ

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Cornelius Cretu

Sat 20 Feb 2016 08:44pm

Hi Paul, All RCDs should trip if the consumer unit is energized and if you short circuit the Neutral wire and the earth wire on any circuit protected by that particular RCD even if the MCBs (circuit breakers) are in the OFF position. Regards,

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