Does my consumer unit have an RCD?

[sonaldo]

Hi. Electrician said my unit doesn’t have RCD and can’t do further work without upgrading it—is this correct?

 

[ericmark]

Simple answer is yes he is correct. There is nothing stopping you using what exists, but can't add.

The are ways, use of SWA cables, Alitube cables, and RCD sockets etc. but likely will cost more than a new consumer unit. But unit to the right does have a RCD, so why not use that one?

 

[opps]

Which work can't he do without upgrading it?

 

[SUNRAY]

Which work can't he do without upgrading it?

He is unable to make any changes to A circuit without bringing THAT CIRCUIT up to current regs. If he is only working on one circuit he may be able to transfer it to the second box.

But to be honest the difference in the amount of work involved upgrading one circuit and replacing what you have with a new Consumer Unit is normally not significant.

 

[ericmark]

Each version of the regulations says something like

BS 7671:2008 Requirements for Electrical Installations was issued on 1st January 2008 and is intended to come into effect on 1st July 2008. Installations designed after 30st June 2008 are to comply with BS 7671:2008.

and it continues to say

The Regulations apply to the design. erection and verification of electrical installations, also additions and alterations to existing installations. Existing installations that have been installed in accordance with earlier editions of the Regulations may not comply with this edition in every respect. This does not necessarily mean that they are unsafe for continued use or require upgrading.
BS 7671:2008 includes changes necessary to maintain technical alignment with CENELEC harmonization documents. A summary of the main changes is given below.

The main point is it refers to "design" so that if the design is not changed, there is no need to upgrade. However often new editions clarify, this then results in a problem, as it can point out that the regulations have been miss read. And this is surprisingly easy to do. One full stop, read as a comma can completely alter what has been said, so there have been cases like the over sleeving of green/yellow cables where people have simply miss read the regulations.

However in the main the regulations are there for our safety, and even if technically something does not need upgrading, often it would be silly not to upgrade, there are some items like the surge protection device, which protect equipment rather than personal, and owners can select not to have them fitted. But items like RCD's we really do need that protection, there can be an argument that RCD's with a TN supply are secondary protection, but my own house, the balcony leaked allowing water to run into sockets in the room below, and the RCBO tripped, on removing the socket, it was found to have distorted due to the arcing inside, so the RCBO tripping likely prevented a fire.

However the last thing I want is for my freezers to stop working, I live in the country, so have to accept that snow may mean a week or more when we can't leave the house, so freezers are well stocked. So my freezers use two RCD sockets and an uninterruptible supply, backed up by batteries and solar panels, these also supply the central heating. Last thing I want to do in my 70's is to have to go out on these steep hills in the snow. Or to loose essential services, so to me all RCBO is really the only option. However back in the 90's in my old house, I fitted RCD's but RCBO's which fitted inside the fuse box were very rare, and I just had two RCD's for everything, and they would trip, and I did loose freezers full of food as a result. But that was better to loosing a son, who had become a radio ham, at 14 year old, so was playing with mains electric.

 

[ebee]

Back in the day we used to design and install all rewireble fuse consumer units and sometimes MCB consumer units, not an RCD in sight (They were more commonly known as Earth Leakage Circuit Breakers too, some were voltage operated and some were current operated - what we might justifiably call RCDs today).
I`m sure there are quite a few of those systems in constant service today.
However, I did, for many years, recommend RCDs as an optional extra. I would point out that if you had a pet dog and it saved your dog`s life then it was worth the additional cost.
So, no RCD in sight, did we even flinch? No, it was normal. I was slightly unusual upon my peers for pushing the RCD stance a bit.
Roll forwards a few years, would a lack of an RCD cause me concern? Yes quite a bit really.
RCDs are no replacement to encourage folks to take other risks that they might otherwise not take, at best they might be considered to be capable of saving 95% of the population and might have a 7% failure rate too, add those figures together and you might still decide be be risk averse.
Using systems from years ago still might be pretty safe, and there is generally no compulsion to upgrade. BS7671 is effectively non mandatory

Having said all of that, would I upgrade and add RCD protection, against maybe other things? Yes!.
BS7671 is effectively non mandatory, However, treat it as though it is, is my motto.

Back in the 60s and 70s we had to get up early every Sunday morning to sweep the dead bodies off the street!

Ok we didn`t, I am exaggerating, but hey ho, upgrade and RCD the thing (Best all rounder is by using RCBOs).
Type A is generally preferable, would a type AC worry me ? not usually.

A while back, RCBOs were very expensive, nowadays as cheap as chips - reminiscent of the "Sinclair Cambridge" calculator, once it started to become popular it was around two weeks wages for some folk for such a very basic calculator, Mr Armstrong and Mr Aldrin got to the moon with a computer system not much more advanced really.

Not long ago you would be happy to fly for a holiday in Italy. Spain etc and the driver would wear a leather jacket and goggles with a long scarf stuck out from his neck.
Would you do that nowadays?

 

[Murdochcat]

The ideal upgrade is to replace the existing uni with one with RCBOs and an SPD and a couple of spare slots

 

[ericmark]

I feel there is a balance, the disruption should a RCD trip v the safety afforded by the RCD. Same for many other things in life, do I cycle to the shops to safe the planet, or use the car and keep me safe, I select the latter, until we have a cycle track I will use my car. Trains don't run in winter, and can't take bike on a bus.

 

[EFLImpudence]

I feel there is a balance, the disruption should a RCD trip v the safety afforded by the RCD.

You are correct but the regulations - which govern scheme members - do not allow for that.

 

[sonaldo]

Simple answer is yes he is correct. There is nothing stopping you using what exists, but can't add.

The are ways, use of SWA cables, Alitube cables, and RCD sockets etc. but likely will cost more than a new consumer unit. But unit to the right does have a RCD, so why not use that one?

the RCD to the right is for the solar panels apparently

Which work can't he do without upgrading it?

i asked if he could remove some plug sockets and install new ones

He is unable to make any changes to A circuit without bringing THAT CIRCUIT up to current regs. If he is only working on one circuit he may be able to transfer it to the second box.

But to be honest the difference in the amount of work involved upgrading one circuit and replacing what you have with a new Consumer Unit is normally not significant.

do you have any idea how much a new CU with RCD costs?

 

[ericmark]

Around £130 for a fusebox CU with SPD and isolator, and 5 RCBO's and likely ½ day to fit it. Labour costs vary so much, hard to guess.

This is the bit not so sure about, will it fit?
It is larger as 6 way not 5, and also two ways for SPD and the MCB that feeds it. Maybe one can just fit RCBO's?

and keep the existing CU? That will cost more in parts, but less in labour, so ask your electrician as to cost.

 

[EFLImpudence]

i asked if he could remove some plug sockets and install new ones.

If by that you mean some sockets merely replacing existing ones then no alterations to the CU would be necessary.

However if you mean new sockets in places where there was none before then these should be on a circuit covered by an RCD.

 

[Vicario]

Is an electric cooker safe if not RCD protected? I thought that they were considered pretty much like electric showers - potentially lethal without an RCD.

 

[EFLImpudence]

Is an electric cooker safe if not RCD protected? I thought that they were considered pretty much like electric showers - potentially lethal without an RCD.

What nonsense.

How did we manage until 2008?

What do you think would happen?

It would be as safe as it always has been.

Electric showers are plastic.

 

[Murdochcat]

PV systems shouldn’t really be on RCDs