Electrical curiosity

robjf

robjf

robjf

Soldato
Joined
31 Oct 2003
Posts
4,577
Location
Derby, UK
I have just bought a house with my girlfriend and up to now everythings been great!

Before we bought the house it was completely rewired and we have paperwork to say its been tested etc.

The other night one I the RCDs randomly tripped and now, following unplugging absolutely everything from the circuits/MCBs which run through this RCD we then tested every light, socket and device. Any level of load whatsoever trips the RCD.

Once I had done all of this I thought it might be a good idea to test the RCD using the test button. With power on to the RCD, pressing the test button does not trip it. What are the likely issues we have here?!

Luckily my dad is an Electrician however he can't get up until next Wednesday as he is working away. We have numerous extension leads running fro
Sockets on the other rcd.

Does this point to a faulty RCD?

Cheers. Rob
 
Possibly. Its either a fault on the RCD or more likely a fault on the circuit. You have not been screwing any screws or nailing any nails into anything have you?

You can get a tester that you plug into various sockets to determine if there's a problem its pretty cheap.

Or you can unplug the RDC and replace it.

Hopefully for you its the RCD or one of the sockets/switches on the circuit as tearing walls and floors up to find a fault is a right royal pain.
 
It'll be a faulty RCD if the button doesn't trip it, I'd get it replaced when your dad gets back. also if you have receipts for the consumer unit you might be able to just get it replaced depending on how old it is.

estimated by the fact the button doesn't work as it should trip when the juice is on even with no load connected, otherwise there might be a fault if it's tripping when it's on.
 
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Well we're hoping for a faulty RCD too, my old mans bringing all his kit up either way, just frustrating to be honest. We have t been knocking any nails in anywhere so I'm pretty sure that won't be the case. The work we have done has pretty much been all cosmetic, no intrisive work.

Dad doesn't get many days off working abroad all the time, but he hasn't seen the house yet so I'm sure he doesn't mind :)

Cheers for the ideas guys.
 
Very unlikely to be a faulty RCD, They dont normally fail in the manner you describe in my experience, thats not to say it isn't just unlikely.

What circuits have you got on that side of the board?. You need to isolate every load fully on live and neutral (so unplug rather than just switch off as your sockets might only be SP switching). Dont forget things like boilers and immersion heaters (the isolators for these are normally double pole so just switch them off)

Then reset the RCD, try it with a heavy load on one of the sockets (eg kettle), if it doesn't trip then you've removed the fault, leave the load connected and put things back un until it trips. Thats about the best I can suggest without A) opening the fuseboard up, B) without test equipment
 
Thanks. On that rcd we have upstairs sockets, downstairs lights, shower, oven, kitchen lights, how do I deal with each of these? For instance is turning the shower off at the switch on the wall enough?

Cheers for the help :)
 
Yeah turn the shower off at the wall switch/ pull cord , thats double pole, whereas the one on the unit itself is often only SP.

Same with oven.

With the lights you cant really isolate it, but do go outside and eyeball any outside lights, make sure they are not full of water, etc

Unfortunatly the sure fire way to narrow down which circuit and eliminate it, involves opening the fuseboard, and best I don't give you pointers on that as there are parts in it which are live all the time and cant be isolated
 
For a start get rid of the bloody RCD's and get some RCBO's. Yes it costs a little more but it stops 1 circuit taking out another 5 or 6 circuits.
The electrical company who done the work for you would come back and fix it free of charge (if reputable). I know I would if it was my install
 
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