Will a new metal CU be mandatory or advisory

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Bob Minchin

Active member
Joined
Jul 3, 2023
Messages
34
Reaction score
15
I've just moved into a flat and want to get an electric shower fitted. The installation has passed a recent EICR done by the seller but warn that the current CU is a plastic type. There is sufficient room to fit extra breakers.

So that I can be best prepared when meeting the electrician, is it mandatory to have the CU changed for a metal one because of the new circuit being added or just advisable.
Money is tight after the purchase and I don't want to pay out if I don't have to. Thanks
 
No provided it is suitable it is fine. Can you show a pic?
Thanks I'll try and get a pic when I get back home. What do you define as 'suitable'? obviously no damage and room for an extra breaker anything else? It possibly original from when built in 1997. It has an RCD
 
Suitable is as you say and the pic to see the nature of any RCD protection and whether protective devices are still available.
 
no need to change it just because its plastic. may need changed if the new circutis can't be fitted, either no MCB's or RCBO's available etc, although that would apply to any consumer unit plastic or metal
 
breakers.jpg

These are the breakers which seem to be still available. there are 4 empty slots and 2 more with unused breakers so a total of 6 slots. So a shower RCD and a suitably rated MCB ought to fit and be OK?

Fingers crossed🤞🤞

Thanks for your responses guys.
 
You just need an RCBO (combined RCD and MCB) unless the spare ways are already RCD protected in which case just an MCB.
 
I plan to have an 8.5kw shower which is ~35 amps I think.
Will a 40A RCBO be adequate or would I be better to go for a 50A type for a bit more headroom?
 
I am surprised it got a satisfactory EICR with a missing blank. I am willing to bet there is a busbar finger waiting for an inquisitive finger next to the main switch.

Because there is only one RCD, for the shower I would fit an rcbo next to the main switch.

Then that leaves another missing blank at the left hand end to be filled.

Looking again, there has been some buggering about with that CU. Labels suggest it used to be dual RCD but not any more? And what's with the left hand rcbo already fed from the RCD.
 
If that is the correct lid then an RCD has been removed.
Edit, just checked the Part No and it should be dual RCD so that has been doctored.
 
If that is the correct lid then an RCD has been removed.
Edit, just checked the Part No and it should be dual RCD so that has been doctored.
Ive got no history. Previous owner died. It was an executor sale. The unmarked items on the left have nothing connected to them. Just space fillers.
 

Latest posts

Top