Hello I have a 1 bed rental and there are some issues with the electrics which a new consumer unit will resolve. I would like some advice please as to whether it is necessary to install one with a RCBO as my electrician seems to think - she says that RCD consumer units will trip out everything if there is a problem? The current consumer box has just one RCD and I am not aware of it ever tripping out once. Also is £600 a reasonable quote for the installation of a RCBO consumer unit? Thanks
Which Unit
- Thread starter Sonny2017
- Start date
Sponsored Links
What issues are we talking about? Thats' step one to a good answer
If you have an RCD already, chances are you don't have a problem - it may not have all circuits covered to current standards, but the regulations are not retrospective - This is assuming sockets (if on a ground floor) are protected it shouldn't fail an EICR because of it.
If you have an RCD already, chances are you don't have a problem - it may not have all circuits covered to current standards, but the regulations are not retrospective - This is assuming sockets (if on a ground floor) are protected it shouldn't fail an EICR because of it.
Which circuit is RCD protected?
Doesn’t sound like a job that requires a new consumer unit, sounds like some terminals need the tightening and that’s it
Doesn’t sound like a job that requires a new consumer unit, sounds like some terminals need the tightening and that’s it
Sponsored Links
Get all RCBOs.
If there is a problem with tripping later on, your tenant will only lose one circuit = less aggro for you and everyone.
If there is a problem with tripping later on, your tenant will only lose one circuit = less aggro for you and everyone.
Might help if the OP posts pictures and a description of the issues.
Personally, I replaced my CUs with all RCBO ones a few year ago so that the installations got a completely "clean" EICR. While not required by regs, there are two reasons I did it :
Note that it's possible to have a fault which will trip a shared RCD even if the MCB supplying the circuit with a fault is switched off - RCBOs eliminate that failure mode as well.
£600 sounds a bit steep to me - but it depends on the work required and how many circuits there are.
EDIT: Just to add, the most common installation is a board with a main switch, two RCDs, and MCBs in two groups. When an RCD trips, it will take out (around) half of the circuits and part of the planning is to work out the least dangerous combination - some like to put upstairs sockets and downstairs lights on one RCD, and vice-versa for the other, so that if the lights are out you can use table lamps etc.
Going all RCBO means that tripping the socket circuit (probably the second most common) won't take the lights out. Just don't have outside lights on the same circuit as the inside lights - I suspect damp in outside lights is the most common cause of nuisance tripping.
Personally, I replaced my CUs with all RCBO ones a few year ago so that the installations got a completely "clean" EICR. While not required by regs, there are two reasons I did it :
- Safety - there were no RCDs before
- CYA - if anything should happen and a tenant tries to claim it was my fault, I have a magic piece of paper which shows that it was in good condition and fully compliant with regs (as they were at the time). That raises the bar somewhat on their burden of proof in trying to make something my fault.
Note that it's possible to have a fault which will trip a shared RCD even if the MCB supplying the circuit with a fault is switched off - RCBOs eliminate that failure mode as well.
£600 sounds a bit steep to me - but it depends on the work required and how many circuits there are.
EDIT: Just to add, the most common installation is a board with a main switch, two RCDs, and MCBs in two groups. When an RCD trips, it will take out (around) half of the circuits and part of the planning is to work out the least dangerous combination - some like to put upstairs sockets and downstairs lights on one RCD, and vice-versa for the other, so that if the lights are out you can use table lamps etc.
Going all RCBO means that tripping the socket circuit (probably the second most common) won't take the lights out. Just don't have outside lights on the same circuit as the inside lights - I suspect damp in outside lights is the most common cause of nuisance tripping.
Last edited:
This are the issues:
Exposed insulation where cable enters ccu
Ring circuit arcking - one of the terminals is rattling
some terminals not properly tight on buzzbar
Earth wire on electric meter not standard
The electrician is saying if the current consumer unit is updated to a RCD there may be more problems than if it was updated to a RCBO.
The attached picture shows the current fusebox.
Exposed insulation where cable enters ccu
Ring circuit arcking - one of the terminals is rattling
some terminals not properly tight on buzzbar
Earth wire on electric meter not standard
The electrician is saying if the current consumer unit is updated to a RCD there may be more problems than if it was updated to a RCBO.
The attached picture shows the current fusebox.
None of those problems could only be solved by upgrading the consumer unit.
That CU is so modern you could just change those 6 MCBs for a RCBOs if you really wanted to, or with some work, another RCD could be added.
I would get advice from another electrician
That CU is so modern you could just change those 6 MCBs for a RCBOs if you really wanted to, or with some work, another RCD could be added.
I would get advice from another electrician
Another electrician said they would also replace the CU. I am wondering if that is the least complicated.
What iggifer said - and for less than £600 
It's only 5 MCBs assuming the one marked spare isn't actually connected to anything. Actually, if you were just replacing MCBs with RCBOs then you only need 4 as the shower is already RCD protected.
It's only 5 MCBs assuming the one marked spare isn't actually connected to anything. Actually, if you were just replacing MCBs with RCBOs then you only need 4 as the shower is already RCD protected.
A lot of electricians probably only have that in their list of solutions. Brings to mind the old saying that if your only tool is a hammer then every problem looks like a nail
Did they both by any chance (incorrectly) tell you that you have to replace it anyway as it's plastic ?If I were trying to minimise cost, I think I'd probably shift at least a couple of those MCBs over onto the existing RCD, and then only have one or two RCBOs to buy.What iggifer said - and for less than £600
For those concerned with 'separation of circuits' ("so as not to cause inconvenience" etc.), it's really only 'being plunged into darkness' by a fault on some other circuit that is the real issue, and putting the lighting circuit on its own RCBO would largely solve that. Having two separate lighting circuits iin a 1-bed flat seems a bit OTT, but there's plenty of space in that CU to do that, and each could have their own RCBO (or, cheaper, one could go onto the RCD and the other have an RCBO).
Kind Regards, John
20A socket circuit and the cooker over to the RCD and then an RCBO on the lights and the other socket circuit. Job done. About £50’s worth of materials for two RCBOs
Yes, they did. They said otherwise I would not comply with the new regulations.A lot of electricians probably only have that in their list of solutions. Brings to mind the old saying that if your only tool is a hammer then every problem looks like a nail
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
