Is RCD a legal requirement for consumer unit?

[cannaefixit]

Hello

I have a fuse box (MK Sentry Consumer Unit BS5486 Pt 13 it says) which contains a main switch and 4 mcbs (lighting, ring main, smoke alarm and cooker). No RCD.

While I believe that RCDs are a good thing (always use one for extension leads) I don't want to upgrade it yet. Can I add anything to my existing circuits without upgrading the consumer unit? Are RCDs now a legal requirement?

rgds

 

[JohnD]

depending on its age (post a pic please) you may be able to fit an RCBO in place of the MCB for the socket circuit.

An RCBO is a single device which incorporates both an MCB and an RCD. It protects a single circuit.

Current standards require all sockets that can reasonably be expected to be used with equipment outdoors to be protected by an RCD. However old installations do not necessarily have to be updated to current standards.

Some (not very good) earthing methods require the whole installation to be protected by an RCD. If you post some pics of your consumer unit, meter, incoming service head and the cables around them, we can tell you more.

 

[luminaire]

BS 7671 (IEE Wiring Regulations) are not law. Like the High way Code is not law, however, if you disregard them you could end up liable to prosecution. So work that out for yourself!

You could for instance put single pole RCBOs on each circuit, which would answer your question; but it would undoubtedly be cheaper to replace the CU with a split-load.

 

[cannaefixit]

Thanks for the info, I will try to post a photo later (camera batteries are dead).
Unit is probably 1980s.

 

[davy_owen_88]

Current regulations are not retrospective nor statutory. Unless you are carrying out work there is no requirement to add RCD protection. On the other hand, RCD's do make for much safer installation, so unless you intend on upgrading in the very near future I still suggest you implement RCD protection (RCBO's or a separate 2-way insulated board with RCD fitted)

 

[JohnD]

...You could for instance put single pole RCBOs on each circuit, which would answer your question; but it would undoubtedly be cheaper to replace the CU with a split-load.

No it wouldn't, he's only got one socket circuit.

 

[plugwash]

the most relavent law to domestic wiring is part P of the building regs which is very very vauge.

iirc BS7671 requires RCD protection on all sockets that can feasiblly supply equipment outside the equipotential zone. On domestic installations this is commonly interpreted as all downstairs sockets though interpretations vary.

adding to installations that are not to current standards without upgrading the relavent bits of them is a thorny issue. it would need someone with more experiance on the building regs in general to answer that one.

I'd say your best bet is to replace the socket circuit MCB with a RCBO. Given that its only one socket circuit it shouldn't break the bank. If you have the older style MK CU (fork style busbar) you will also have to get thier "MCB retrofit kit" (basically it includes a short peice of new style busbar and a special cable for joining the two bussbars).

 

[JohnD]

I'd say your best bet is to replace the socket circuit MCB with a RCBO.

Couldn't agree more

 

[securespark]

RCBO man strikes again!

You should seriously consider changing your name to JohnRCBO....

 

[cannaefixit]

Hello again.

Sorry for the delay getting back but here's the reason.

To be completely honest with you, what prompted my original post was getting a quote from a local firm of electricians for some minor kitchen work (£300). That seemed pretty steep to me even before the guy looked at my consumer unit and told me that not only could he not do the kitchen work before the CU was changed for an RCD type, he could, and should, lock down my supply until that work was done (£250). Not good news; I've just blown some record, never-to-be-repeated overtime on a new kitchen and £550 is money I just don't have.

Anyway, by coincidence, I just got a letter from the local Southern Electric office. They're offering a free visual wiring inspection to owner-occupied properties over 15 years old so I went for it. Their inspector has just been and I thought you might be interested in what he had to say (particularly JohnD and plugwash to whom many thanks).

Basically he found the wiring all sound, the (PME) earthing system in good order and with recently uprated earth cabling, earth bonding all good throughout the place and the ONLY recommendation he came up with was to put an RCBO on the socket ring. Furthermore he said that Southern electric prefer individual RCBOs to split boards or whole boards that are RCD-protected (although SE would fit those if requested).

At this point I told him I'd been advised to get an RCD-protected unit but didn't go for it on the grounds of cost and also because I don't like the idea of my whole place being plunged into darkness if there's a fault on one circuit (I mean, that seems to undermine one of the main reasons for having separate circuits in the first place).Anyway he agreed with that, told me the CU is a current model and then wrote down the details of the RCBO I need (£30ish not £250). He left saying my wiring was in good condition and, apart from the lack of a RCBO on the socket ring, it complies with current standards and there was nothing else of concern.

So a big "thank you" to you all, especially JohnD

 

[plugwash]

nice to see a good result

in general though i would be wary of free inspections, lots of places offer them as a means to get a foot in the door and do work thats not really nessacery.

 

[JohnD]

A good result from a good company

http://i113.photobucket.com/albums/n228/JohnD_UK/SSEbook.jpg

(just one of my previous lives)