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]

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