help with new consumer unit and tripping RCD

[darren bergin]

youve also got exposed live contacts from the busbar..

 

[wiggles]

can you see any obvious problems?

Yes, your mainswitch is on with the CU cover off. Danger of shock, death etc. Remember, even with the main switch off, the tails supplying it are still live but at least the busbar should be dead.

 

[plugwash]

Here's my consumer unit - it looks a bit tangled in there, but can you see any obvious problems?

The spare bussbar fingers are exposed, Ideally you should have either rail mounted blanks or some form of cover of them.

as others have said try not to have a CU cover open with the mainswitch on and if and when you have to (you have to for certain types of testing for example) take extreme care especially with one like this where there is exposed busbar fingers.

 

[Taylortwocities]

your neutrals for the ring main look to be on the non - rcd side
wired incorrectly

Agreed, I hope you didnt pay him yet? Get him back to do it properly - also the wiring inside of the consumer unit is a total disgrace.

I trust he is a full scope member of one of the Part P schemes and has notified the local authority and provided you with a full Electrical Installation Certificate??

 

[martinsell]

hmm. OK, thanks guys. I suspected it wouldn't be good news. I'll get him or someone else back to review the consumer unit.

In the meantime, do you think his diagnosis of faulty fridge and PC is likely to be correct? Are there simple tests I could do with basic equipment like a multimeter?

The electrician hasn't received full payment yet so I have a bit of leverage. He said he'd do me a certificate once the (possibly) faulty appliances were fixed, when he'd be able to put the primary main ring circuit onto the RCD (though he said that the cert would explicitly exclude my kitchen, which is a bit of a nightmare).

I wasn't aware of a requirement to inform my local authority - what's that about?

 

[JohnD]

In the meantime, do you think his diagnosis of faulty fridge and PC is likely to be correct?

No

When you have a split load CU, with some circuits protected by an RCD and some not, it is ESSENTIAL that for each circuit, the Red (or Brown) and Black (or blue) wires for that circuit must both be on the same side. So either both must be on the RCD side, or both must be on the non-RCD side. Failure to observe this simple rule guarantees that the RCD will trip, since it operates by measuring any difference in current flowing between the L and the N wires

If your electrician does not understand this simple rule I do not believe he can possibly be competent. I would send my granny round to do a better job if she was still alive.

 

[Steve]

also the wiring inside of the consumer unit is a total disgrace.

You aint seen nuffin yet . . .

This is my CU, fitted by a NICEIC bloke. Isnt it pretty . . .

 

[plugwash]

Yep very clearly one of the rings has its lives connected to a breaker on the RCD side but it's neutrals going to the non-rcd bussbar. I strongly suspect that is the cause of the tripping problem.

It should be simple enough to fix, just find the two neutrals that belong to that circuit and move them to the correct neutral bar.

 

[Spark123]

I wasn't aware of a requirement to inform my local authority - what's that about?

Replacing a consumer unit is notifiable to your local area building control under Part P of the building regs. If your electrician is a member of a competent person scheme then he can self certify compliance with the building regs via his scheme. If not then to comply with the law, he must notify the local area building control and pay their fee before he starts work, they will then oversee compliance with the building regs.