Help with a tripping circuit!

Roaming

Hello!

We've recently had some new sockets put in and nearly all the sockets and switches recessed in our house.

The electrician who has done the work says he has 'upgraded' the wiring in the house and moved everything to the RCD.

Having eveything on the RCD is now a requirement? Can someone please confirm this?

Now, as part of this work, the light on the upstairs landing trips the RCD everytime you turn it on from the upstairs switch but not when you turn it on from the downstairs switch ( I'm not certain about it tripping the RCD or not when turned on from the downstairs switch). This obviously only happens when there is a bulb in place. He tried to leave it at, there is something wrong with the bulb till we pointed it out today after having tried 2 different working bulbs.

His explanation is that we have a faulty RCD and it would cost a bit to replace it so he has put that light switching circuit back on the old circuit.

I'd like to add that as part of the contract, they had said (we have this in writing) 'Add new RCD to existing fuse board' - this should imply that they should have given us a new RCD regardless - right?

Back to the problem though. An RCD is supposed to trip due to current leakage and if its only tripping on one circuit, then its something wrong with that circuit, not the RCD - am I correct?
He has signed off his work and for the meantime, has moved things back to the old circuit so they work and given us the RCD excuse alogn with the fear of having to spend more money to get it sorted. I feel we should not accept his work as satisfactory beacuse if he is moving thigns on to the RCD that previously weren't then he needs to make sure that whatever goes on there, goes on there without any problems, and if there are, he needs to fix them rather than make up an excuse for it. I worry that he is unable to find the cause of the leakage and therefore is making excuses which means if we want it to work the way it should (and be ont he RCD) we may have to pay for someone else to come have a look at it. What would you do in this situation?

Would really appreciate some help with this!! Going to try to talk this out with them tomorrow morning.

rrf494g

Don't accept the excuses . . .

The rcd trips because there is something wrong! There is a (slight) chance that it is the rcd, in which case as you suggest a replacement rcd is needed. Don't be fobbed off. The rcd is a safety device, and as such, to bypass it when it indicates a problem, is daft.

good luck

macman

All he has to do is to swap the RCD to test it and rule it out (or in) as the problem. 5 minutes work.

Roaming

Thank you macman - If testing it is so straight forward, wondering why he didn't or hasn't decided to do that? It is a big cost?or is he just not bothered about fixing the problem or is he using that as an excuse not to have to go about tracing the real point of current leakage.

macman wrote: »

All he has to do is to swap the RCD to test it and rule it out (or in) as the problem. 5 minutes work.

zax47

Sounds to me what us electricans called a "borrowed neutral" - very common fault when wiring hall/landing lights, two way switched. It trips the RCD cos the neutral is from the downstairs light ciruit and the live from the upstairs - or vice-versa. It's very common, and it's not dangerous per se - the light will work fine wired this way, but annoys the RCD! RCD trips when it sees an imbalance in the current flowing between live and neutral in that part of the circuit, in this case the lights on the stairs are wired across two different circuits so it's tripping the RCD. Any electrician who knew his stuff would know this and recognise the symptoms of a borrowed neutral - sounds like you got a cowboy (in my opinion!)

If he only added to the socket circuit then that's all that needs to be RCD protected - the regulations are not retrospective UNLESS you do some new work, as in this case.

fluffpot

Sounds like it might be a borrowed (shared) neutral between the up and downstairs lighting circuits. This would not have been an issue before if there was no RCD protection to the circuits. This needs to be resolved before he can sign off the work, but if he though this was 'acceptable' then he doesn't sounds like a very good electrician!

Beat me to it by about a nanosecond!

just a thought - are ALL your circuits now on 1 RCD? ie when it trips you loose power in everything - lights, sockets etc? If so, this again is pretty bad practice and a major inconvenience for you. there are better solutions.

Roaming

Hi Fluffpot! Yes, we lose power throughout the house when the RCD trips.

How does one go about knowing what is and is not good practice about these things - unless one is seasoned by years of DIY and learning about it. :-/ We are first time home owners and this is our first encounter with tradesmen. So, for the most of it, we are relying on the tradesmen to do an honest job.

What would I do without this forum and you guys!

fluffpot wrote: »

Sounds like it might be a borrowed (shared) neutral between the up and downstairs lighting circuits. This would not have been an issue before if there was no RCD protection to the circuits. This needs to be resolved before he can sign off the work, but if he though this was 'acceptable' then he doesn't sounds like a very good electrician!

Beat me to it by about a nanosecond!

just a thought - are ALL your circuits now on 1 RCD? ie when it trips you loose power in everything - lights, sockets etc? If so, this again is pretty bad practice and a major inconvenience for you. there are better solutions.

zax47

Snap! Great minds eh......

Roaming

Well this came about because he moved the old wiring that was previously NOT on the RCD (according to him) On to the RCD. It was working fine before and again works fine as long as its not on the RCD. You are right about his experience though Not suer I'd call him a cowboy but he is definitely a novice - just out of training/apprenticeship I think... or perhaps even still on it!

Would you suggest we discuss this with him and ask him to sort it out because if its something as obvious as that then it shouldn't be all that mind boggling to him either. He does mention standards and regulations all the time which made me trust him to start off with. Or is that a Newbie thing to do?

zax47 wrote: »

Sounds to me what us electricans called a "borrowed neutral" - very common fault when wiring hall/landing lights, two way switched. It trips the RCD cos the neutral is from the downstairs light ciruit and the live from the upstairs - or vice-versa. It's very common, and it's not dangerous per se - the light will work fine wired this way, but annoys the RCD! RCD trips when it sees an imbalance in the current flowing between live and neutral in that part of the circuit, in this case the lights on the stairs are wired across two different circuits so it's tripping the RCD. Any electrician who knew his stuff would know this and recognise the symptoms of a borrowed neutral - sounds like you got a cowboy (in my opinion!)

If he only added to the socket circuit then that's all that needs to be RCD protected - the regulations are not retrospective UNLESS you do some new work, as in this case.

fluffpot

I feel for you I do. How can you tell - you can't sadly but at least you had the sense to ask here.

You are well within your rights to ask for the work to be done properly. If you are paying him then he needs to do the job right. As mentioned the possible borrowed neutral needs to be rectified and the circuits need to be split across more than 1 RCD. This can either be done by fitting a dual RCD fuse board or by replacing the original circuit breakers with rcbo's (which are circuit breaker and RCD combined). Can you post a pic of the fuse board? Might be able to advise if the latter is possible - might be more cost effective than a new board

Also worth asking to see the results of tests he should have carried out on the circuits he worked on - if you can post them here, it might give us a clue..

Roaming

That would be great! I've got a photo but how do I post it?

Don't have the results sheet - I think its with the main contractor. I can ask him to bring it in tomorrow morning and then I'll post it as well.

fluffpot wrote: »

I feel for you I do. How can you tell - you can't sadly but at least you had the sense to ask here.

You are well within your rights to ask for the work to be done properly. If you are paying him then he needs to do the job right. As mentioned the possible borrowed neutral needs to be rectified and the circuits need to be split across more than 1 RCD. This can either be done by fitting a dual RCD fuse board or by replacing the original circuit breakers with rcbo's (which are circuit breaker and RCD combined). Can you post a pic of the fuse board? Might be able to advise if the latter is possible - might be more cost effective than a new board

Also worth asking to see the results of tests he should have carried out on the circuits he worked on - if you can post them here, it might give us a clue..