New RCD Consumer Unit keeps tripping

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I just had a new consumer unit put it by a NICEIC approved electrician. However, just about everything is tripping it. for example, switching the central heating on, turning the shower or cooker on or even just plugging something into an electrical socket. Any idea what could be wrong with it.

The electrician has just told to wait and see what could be causing it but with virtually no heating, it getting difficult to wait and see.

He has already given me a certificate that says everything is in perfect condition but obviously it is not!!!!

Please can anyone help.
 
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He has already given me a certificate that says everything is in perfect condition but obviously it is not!!!!

Then he's either falsified his certificate, or you have some connected equipment causing the tripping.

Does your certificate include a page of test results? If so, what values has he recorded under the columns for Insulation Resistance?

You could try switching off all the circuits on the RCD side of the board. If the RCD still trips there is a problem which is likely down to the spark.
 
i think he probably got in a pickle with his neutrals and stuck one in the wrong nuetral bar after testing.
get him back,it should take him minutes to fix it
 
99% sure it's a neutral conductor connected to wrong neutral bar.

I'm surprised electrician didn't pick this up when doing final live tests
 
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No 'electrician' should ever make the neutral placement error, but it does happen and few do any proper testing. That's why I'm interested in what, if any, test results accompany this certificate.
 
I'll put my hands up to doing it once - somehow I'd got the wires crossed behind the din rail.


The mistake was picked up straight away when I did Zs test - and this was my 1st assessment job!!
 
Did your old fuse board have an RCD fitted?

If the RCD is tripping under load then it could suggest a neutral to earth fault somewhere on the installation.
 
On the insulation resistance column it says 1000 M ohms for all the circuit number. Does this mean anything? Obviously being a Sunday, I can't seem to get hold of him.
 
We didn't have a RCD in the old consumer unit.

I have switched everything off. Unplugged everything. So there should be absolutely no live current. Switch the consumer unit onto on. Then we plugged a table lamp with a 60W bulb and RCD trips. Then we try plugging a radio, drill. Trips again.

We repeat with switching everything off, and then switching the heating on, then shower, then immersion heater, then lights. Trips everytime.

Is it possible that we have a dodgy RCD?

or bad insulation somewhere? I remember we accidentally drilled into a wire some years back and we fixed it with an electrical crimp. Could this be the problem?
 
Try as you did ,with only 1 breaker on at a time , you might be able to pinpoint the circuit , and leave just that off for now.
 
On the insulation resistance column it says 1000 M ohms for all the circuit number. Does this mean anything?

Yes, it means that he didn't actually test the insulation resistance at all and that he doesn't actually understand what to record in those columns. It's almost unheard of, for an existing installation, to get perfect results on every circuit. (I expect, also, that you have lots of boxes with "N/A"s or strike-throughs in them too? )

The problem you have should have been apparent when he did the work and leaving you with an unuseable installation is simply unacceptable. You need to insist that he return immediately and correct his work. A report to Trading Standards is a more effective threat than the NICEIC, by the way.
 
Have now spoken to the electrician. He says he did test the insulation and recorded all the columns as 1000mohms because all the readings were over 1000.

We tested each circuit on its own, with the other MCBs switched off and the one MCB on still tripped the RCD.
 
He says he did test the insulation and recorded all the columns as 1000mohms because all the readings were over 1000.

Quite unusual - I have never yet found an installation old enough to need a replacement consumer unit which returned IR values on all conductor combinations in excess of 1000Mohms - but let's give him the benefit of the doubt. (He should have recorded the values as greater than 1000, though.)

The RCD works by monitoring the currents in the line and neutral conductors that supply it. Any current 'leaking' from a circuit supplied via the RCD will result in an imbalance and if this imbalance is greater than the (quite sensitive) rating of the RCD it will trip.

So, in effect, the current flowing 'in' to the top of the RCD through the brown wire must equal the current flowing 'out' of the blue wire.

One of the most common faults masked by non-RCD consumer units is a neutral-to-earth fault. This would be found by properly testing insulation resistance.
Then there could be a borrowed neutral, which any qualified electrician should always be on the lookout for and problems would become apparent as soon as things got switched on, which is/should be part of the testing process.
Then there is faulty connected equipment, but you would have been able to narrow this down quite quickly. (And, if there was equipment which was not able to be disconnected, this would also have been discovered during IR testing!)
Crossed neutrals, the problem most respondents have suggested, should also have been evident as soon as the installation was re-energised (during the post-operative cup of tea stage). But this problem is simple to identify and correct.
And a faulty RCD should have also been discovered during testing, although it is just possible that the fault developed after completion.

We tested each circuit on its own, with the other MCBs switched off and the one MCB on still tripped the RCD
.

Is this only on one particular circuit, or does it happen with any circuit?
 
I'l bet you a fair few drinks on his paperwork it says

"NICEIC DOMESTIC INSTALLER"

:rolleyes:
 

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