consumer unit and RCDs

[beatrix]

Hi

We are in the process of having a kitchen extension. This has resulted in the electrician replacing the consumer unit. The electrician has said there is a fault with the lighting circuit but has not wired it to the RCD. Is this acceptable?

Our worry is that it is not safe and need advice on what to do.

 

[PrenticeBoyofDerry]

Any electrician worth their salt, would have done tests prior to installing a new CU, to confirm suitability for swap and to identify any faults that require resolving.
Whether this is acceptable would depend on the fault that has been diagnosed and whether the lighting circuit requires RCD protection.

With regards to safety again that would depend on the fault and if RCD protection is required on that circuit.

I suggest you ask the electrician what type of fault they have found, I assume it is not a fault but more than likely a borrowed/shared neutral that is causing a trip fault. If your electrician cannot diagnose the fault correctly, not much of an electrician!
Where in the UK do you live, as England and Wales will require building controls notification for this type of work.
What has the electrician put on the certificates, with respects to remarks on the circuit and departures from BS7671?

 

[ericmark]

As said it is common to have borrowed neutrals on lighting circuits where they have been split into up and down stairs to be able to use more power than originally designed for.

It is a problem as most quick fixes in some way have a draw back.
1) Return to single MCB for all lights as well as possible overload causing MCB to trip once on RCD protection a single fault can cause loss of all lights.
2) Run new cable between the two way light switches up stairs and down stairs really the correct way but causes a lot of work and disruption.
3) Remove the two way system this is likely the best method radio control two way can replace the hard wired system but expensive.

If it is the typical two way stairs lighting causing the problem one option not available is to use not RCD protected as what have been highlighted is a very dangerous situation of a borrowed neutral and once found it really must be corrected.

Of course I'm guessing it is due to two way lighting but that is the most common problem found when fitting a consumer unit and any good electrician would always test for this before starting and would agree with you before starting how to rectify the problem.

It could be something completely different we wait to hear what he entered on the installation certificate.

 

[sparkwright]

We must remember it could just be a fault though, typically earth and neutral shorted out or reversed somewhere.

 

[JohnW2]

... one option not available is to use not RCD protected as what have been highlighted is a very dangerous situation of a borrowed neutral and once found it really must be corrected.

Could you perhaps explain the thinking behind that? Thanks.

Kind Regards, John

 

[beatrix]

Hi

We are in the process of having a kitchen extension. This has resulted in the electrician replacing the consumer unit. The electrician has said there is a fault with the lighting circuit but has not wired it to the RCD. Is this acceptable?

Our worry is that it is not safe and need advice on what to do.

Since posting the above I have got abit more info. The electrician did not test the existing circuits before wiring them to new consumer unit and the RCD but confirmed it is a "fault "with the existing lighting circuit (for the main house) which could be down to wiring/electronics such as dimmer switches/light fittings/transformers. The electrician has removed the lighting circuit from the Rcd protection and moved the circuit to the non Rcd side as this was the only way to allow us to continue using electricity without it tripping when we switched a light on until the issue can be rectified. I was told that he could still issue an installation certificate with a limitation as not able to test the faulty circuit properly. The NICEIC have said if any of the wires are installed in walls within 50mm then for regs they need to be RcD protected and an electrician can not install the circuit in the non RcD side as this would not be compliant.

How can we be sure that all our electric is safe and if there was a fault with an existing circuit should the electrician who has discovered the fault be responsible for correcting it?

 

[JohnW2]

The electrician has removed the lighting circuit from the Rcd protection and moved the circuit to the non Rcd side as this was the only way to allow us to continue using electricity without it tripping when we switched a light on until the issue can be rectified. I was told that he could still issue an installation certificate with a limitation as not able to test the faulty circuit properly.

Why could he not 'test the faulty circuit properly' - was he just not competent, or what?

The NICEIC have said if any of the wires are installed in walls within 50mm then for regs they need to be RcD protected and an electrician can not install the circuit in the non RcD side as this would not be compliant.

That is only true if the cable buried in the wall is new - if it was already there, then the currents regulations do not apply retrospectively, so RCD protection would, strictly-speaking, not be required.

How can we be sure that all our electric is safe ...

Only by having it properly tested, and the fault identified and rectified, by someone who know what (s)he is doing!

....and if there was a fault with an existing circuit should the electrician who has discovered the fault be responsible for correcting it?

That depends entirely on what you engaged, and paid, the electrician to do, and what was the agreed scope of his work. You can't blame him for there being a (presumably pre-existing) fault on the circuit - so it's not his responsibility unless he agreed to rectify any faults he discovered whilst changing the CU as part of that job. Did he not even offer (perhaps 'for a price') to ascertain the cause of the fault and rectify it?

Kind Regards, John

 

[westie101]

How can we be sure that all our electric is safe and if there was a fault with an existing circuit should the electrician who has discovered the fault be responsible for correcting it?

The fault could have been there for years so just finding it doesn't make it any more or less dangerous than it was before the consumer unit was changed.

The responsibility for having it repaired rests with yourself to engage (and pay) a suitably qualified person to find and repair it.

 

[AndyPRK]

Do you have 1 or 2 light circuits?

 

[undistilled]

As Westie101 says, the fault was already there - not created by, but merely discovered by the electrician. If you take your car to the garage and tell them to change the pads and discs and they ring you later to tell you the brake calipers are knackered so no point in putting new pads/discs on without doing the calipers as well are you going to tell them it is their responsibility as they undertook the work in the first place?

 

[JohnW2]

The fault could have been there for years so just finding it doesn't make it any more or less dangerous than it was before the consumer unit was changed. ... The responsibility for having it repaired rests with yourself to engage (and pay) a suitably qualified person to find and repair it.

Is this a case of 'great minds'? ....

That depends entirely on what you engaged, and paid, the electrician to do, and what was the agreed scope of his work. You can't blame him for there being a (presumably pre-existing) fault on the circuit - so it's not his responsibility unless he agreed to rectify any faults he discovered whilst changing the CU as part of that job.

... or just an echo?

Kind Regards, John

 

[westie101]

Yes!