Newly installed Consumer Unit is tripping RCD's when hoover or kettle on

[carlitto74uk]

Hi all,
I'm new here so bear with novice questions pls.
I have renewed an old CU (the one with pull out fuses) to a very new one with 2 rcd's and 10 MCB's. the old one had the kitchen sockets and the 1st floor sockets on the same ring (weirdly).
Layout is this:
RCD1 63A with:
1 x 40A MCB for cooker
1 x 32A MCB for ground floor sockets
1 x 6A MCB for the ground floor light
RCD 63A 2 with:
1 x 50A MCB for electric shower
1 x 32A MCB for 1st floor sockets
1 x 6A MCB for the 1st floor light
1 x 16A MCB for intruder alarm

Switched all on and no tripping. Powered up various apliances (small consumers like TV, DVD, lamps even DW and WM and FF) still all ok - no tripping. When I power up hoover of kettle from any socket both RCD's trip however the corresponding MCB's stay on.
should I disconnect all radials and leave just the mains rings and see if anything changes?

Any thoughts? Tks

 

[Marvo]

What tests did you do before you installed the new CU? What were the IR reading on the circuits and what was the global IR reading?.

 

[trev]

Do you own or have access to calibrated test equipment?
Did you use it before trying the bang test?

 

[trev]

Why did you put the ground floor lighting on the same RCD as the ground floor sockets?
Same question obviously applies to the upper floor lighting and sockets
A 16 amp MCB for the alarm?

 

[sparks123]

probably cross neutral caused them..

 

[ImpededLoop]

It sounds like you've got your neutrals crossed over.

As others have said, you need to carry out the full test procedure to ensure all circuits are ok for continued use.

 

[Prat P]

Hi all,
I'm new here so bear with novice questions pls.
I have renewed an old CU (the one with pull out fuses) to a very new one with 2 rcd's and 10 MCB's. the old one had the kitchen sockets and the 1st floor sockets on the same ring (weirdly).
Layout is this:
RCD1 63A with:
1 x 40A MCB for cooker
1 x 32A MCB for ground floor sockets
1 x 6A MCB for the ground floor light
RCD 63A 2 with:
1 x 50A MCB for electric shower
1 x 32A MCB for 1st floor sockets
1 x 6A MCB for the 1st floor light
1 x 16A MCB for intruder alarm

Switched all on and no tripping. Powered up various apliances (small consumers like TV, DVD, lamps even DW and WM and FF) still all ok - no tripping. When I power up hoover of kettle from any socket both RCD's trip however the corresponding MCB's stay on.
should I disconnect all radials and leave just the mains rings and see if anything changes?

Any thoughts? Tks

Possibly you have mixed up the 2 legs of the ring circuits and so 1 leg from 1 circuit is in with 1 leg from the other ring..should be easy enough to verify this,with or without test equipment.

 

[Simonslimline]

This really is getting silly now.

 

[trev]

Possibly you have mixed up the 2 legs of the ring circuits and so 1 leg from 1 circuit is in with 1 leg from the other ring..should be easy enough to verify this,with or without test equipment.

So how come the sockets are not tripping the RCDs when the washing machine, fridge, dishwasher and other small appliances are used?

 

[not clever]

Diyer or Electrical Trainee

 

[7029 dave]

Any form of testing OP before & after.?

 

[sparks123]

Possibly you have mixed up the 2 legs of the ring circuits and so 1 leg from 1 circuit is in with 1 leg from the other ring..should be easy enough to verify this,with or without test equipment.

Its not specified on ring or other individual circuit. if any of neutral who have to be on one RCD part and you accidentally fixed on the next RCD part they caused tripping when you switch on any equipment except electronic one..im pretty sure this tripping its caused by cross neutral..

 

[Prat P]

So how come the sockets are not tripping the RCDs when the washing machine, fridge, dishwasher and other small appliances are used?

I thought the sockets were tripping RCD with any item ,if its just tripping with 2 items out of a houseful then the socket they are plugged into may have loose connection or the items are faulty

 

[carlitto74uk]

corrention: RCD's trip only when hoover/kettle is connected to 1st floor ring they seem to be ok when supplied from GF ring. Also electric shower (Mira Azora) trips RCD's when NOT on cold water.
I am no electrician I have only basic knowledge or electrics hence I didn't run any Insulation Resistance tests before swapping. I have a Fluke 175 which I mainly use for DC testing can it be used for IR testing?
I don't think there are any neutrals crossed as small appliances work ok. All I've done was swapping rings/radials one by one.

 

[carlitto74uk]

I plug in hoover/kettle in any og 1st floor sockets and RCD's trip. I do the same in any GF sockets and all is ok

 

[trev]

Well this is what happens when people bugger about with things they have little or no knowledge of how to do them properly.
You have no idea if any of these circuits are safe to energise, let alone use. There are good reasons why we test and why we test in the order that we do.
You can either get an electrician in to test this and make sure it's safe or continue to bugger about with it and hope you get it right.

 

[Prat P]

Well this is what happens when people bugger about with things they have little or no knowledge of how to do things properly.
You have no idea if any of these circuits are safe to energise, let alone use. There are good reasons why we test and why we test in the order that we do.
You can either get an electrician in to test this and make sure it's safe or continue to bugger about with it and hope you get it right.

I think this is good advice,no disrespect intended but you are obviously out of your depth and literally messing with fire. Some people assume incorrectly that everything must be working ok if you don't hear a big bang..electricity is dangerous. You would be wise to let an electrician assess the installation.

 

[carlitto74uk]

Update:
I've just moved everything to RCD 1 (EXCEPT for the shower which is still on RCD 2). All seems fine now I powered up all big appliances And the shower at the same time for ab 3 mins now - no trips. Does it mean that I have reverted to my old set up where 2 RCD's have been installed and for the shower and one foe all others? How safe is this? Old CU has worked fine for the last couple of years now with all existing appliances except for the shower which I installed today hence the CU renewal...

 

[carlitto74uk]

Update:
I've just moved everything to RCD 1 (EXCEPT for the shower which is still on RCD 2). All seems fine now I powered up all big appliances And the shower at the same time for ab 3 mins now - no trips. Does it mean that I have reverted to my old set up where 2 RCD's have been installed one for the shower and one for all others? How safe is this? Old CU has worked fine for the last couple of years now with all existing appliances except for the shower which I installed today hence the CU renewal...

 

[sparks123]

....................................................................................................

 

[sparks123]

Update:
I've just moved everything to RCD 1 (EXCEPT for the shower which is still on RCD 2). All seems fine now I powered up all big appliances And the shower at the same time for ab 3 mins now - no trips. Does it mean that I have reverted to my old set up where 2 RCD's have been installed and for the shower and one foe all others? How safe is this? Old CU has worked fine for the last couple of years now with all existing appliances except for the shower which I installed today hence the CU renewal...

its seams now neutral its on the right place and not crossed any more and for that you not have any tripping..now carefully move all that circuits from RCD 1 to the original RCD you install before and see whats happened..but carefully check all neutrals if its on the right place..99% of this kind of tripping caused by cross neutrals if you understand whats mean '' cross neutral ''..

but the best advice its what Trev says to you..

 

[carlitto74uk]

tks for the advice spark123 just one question: if neutrals crossed before moving almost everything to rcd 1 then why small appliances (i.e. tv, pc even fridge) were working fine. only big appliances caused trips when powered up

 

[carlitto74uk]

no disrespect here but if I followed certain people's advice I'd probably need a quualified electrician to change a light bulb...
i thought this forum was intended for diy advise also...

 

[Knobhead]

Get him in the DIY section!

 

[carlitto74uk]

u'r prob right tony as said before i am new to this forum i didn't know where to post this thread i'll know from now on

 

[Pondy]

I agree with trev. This is a classic case of someone attempting electricial installation work without the knowledge or test equipment to make sure it is done safely. The only way forward I can see is for you to get an experienced electrician round with the proper test gear to find the fault for you. I know it sounds a bit harsh but would you attempt to replace the brakes on your car, and when they don't work go round to the main dealer and say to the mechanic, excuse me where have I gone wrong with fitting these brakes to my car, they would quite rightly say bring the car in and we will do it properly for you. It's the same thing.

 

[markc123]

In one of your posts you've said the old CU worked fine ...

Is there any reason you've decided to sling a 17th board in ? Or is it as it seems, and literally just for the hell of it.

Follow the testing sequence ... if you're not sure, like you quite clearly state then ring a professional. I'm all for helping DIY'ers where possible, but this isn't safe to advise online im afraid matey. Could be opening a can of worms here ... and for that reason, im out.

All the best.

 

[sparks123]

tks for the advice spark123 just one question: if neutrals crossed before moving almost everything to rcd 1 then why small appliances (i.e. tv, pc even fridge) were working fine. only big appliances caused trips when powered up

as i know electronic equipment do not tripping RCD if there its a cross neutrals..why ???..i dont know ..same problems its happened to me a long time ago and when i investigate neutral connection i find one neutrals cross to other RCD..after i move them on the right place problem its sort out..in some old installations electricians who do not have access to the right neutral on the one circuits , borrow them from the other circuits..on my experiences i find this problems on old installation on lighting circuits..dont be surprised for that because on the electricians installation industry survive many cowboy electricians..

 

[sparks123]

in the end of this story i can say '' the consumer unit installation '' its not DIY jobs man..or at list you have to be supervised by competent person..

 

[SparkyJoe]

Its not a diy job is it!!!

I mean you could argue that changing a light fitting or a socket could be done by anyone, but what you are attempting is daft. If you screw up said socket/light change the fuse might blow, if you screw up the db change you have nothing much to fall back on.
You're right you don't need a electrician to change a lightbulb (its a lamp) You do need one to change a disboard.

 

[Knobhead]

Get him in the DIY section!

u'r prob right tony as said before i am new to this forum i didn't know where to post this thread i'll know from now on

Ask one of the moderators to move you and this thread. There’s some qualified guys in there that may be willing to help, I’m not one of them!

 

[Pete999]

Did you carry out any tests prior to swapping the CU?

 

[Deleted member 9648]

There is an unfinished sticky on DIY electrics on this forum. Me thinks we need a full and clear sticky explaining that replacing a CU is not as simple as most think.

1. Replacing a CU comes under part P and it is illegal to.... a.Do so without notifying BC.....and b. without complying with Bs 7671.
2.Notifying BC yourself will probably cost more than paying a registered electrician to carry out the whole thing.
3.Complying with 7671 will include tests/inspections to verify the effectiveness of earthing and bonding,and tests and inspections to verify existing circuits are in a fit state to be connected to a modern CU.
4.A modern RCD protected CU will pick up faults and incorrect connections that your old CU wont.This is why tests are carried out before and during the replacement. These tests can only be carried out with proper equipment and the knowlege to use it. A neon screwdriver....martidale plug in tester....or multimeter will not carry out the required tests.
5.Those who think it's a simple swap will inevitably end up in the same boat as the OP here,and even if it works they may still have a dangerous CU without knowing it......and will have broken the law.

 

[Octopus]

no disrespect here but if I followed certain people's advice I'd probably need a quualified electrician to change a light bulb...
i thought this forum was intended for diy advise also...

Yup.

1. Call a registered competent spark
2. Spark refits CU
3. Spark includes full set of tests and issues EIC
4. Spark notifies LABC to comply with building regs
5. Numpty handyman pays extra bills
6. Happy customer.

Sorted.

 

[telectrix]

you could always nip down to b&q and ask that nice man in the orange overalls how to do it. if you're lucky he will give you a shiny little brochure on how to. one sentence in that brochure will be 2 get a qualified electrician to fit it".

 

[Marvo]

no disrespect here but if I followed certain people's advice I'd probably need a quualified electrician to change a light bulb...
i thought this forum was intended for diy advise also...

It is intended for DIY advise as well but there's a limit to the work DIY'ers with a limited skill set and limited range of test equipment should be doing.

The tripping issue you have is just a symptom of a more serious problem which it sounds like you are lacking the competency and test equipment to remedy safely. I can only advise you get a professional in to help you finish this job to a standard where it's safe for the users of the installation and the work can be notified as required by law.

I'm closing this thread because it running any longer is just likely to encourage an unsafe outcome.