Does my new split-load CU plan sound OK (RCD + RCBO)?

[Hibbo]

Hello hello,

Next year I will be renovating my 2 bedroom flat, I am just starting to get my ideas together and start pricing things up, so I thought I'd check that I'm on the right track.

(I am an industrial controls/instrument tech by trade, I have passed 16th Edition and G&G 2391, but have never used them, so although I'm an electrical technician, I'm certainly not a domestic spark).

Anyway, my plan is:

A split load consumer unit with a 30mA RCD, on the RCD side there will be
32A MCB - Socket outlets ring
6A MCB - Lighting
40A MCB - Shower
On the non-RCD side;
32A RCBO - Kitchen sockets ring (and combi boiler on FCU)
6A MCB - 'emergency' light (a simple lamp fitting and pull-cord mounted on the wall next to the CU - no buried cables or anything.

Does this sound OK? I think it covers all the 17th Edition RCD requirements, and reduces the risk of me losing my boiler and FF unneccessarily, and is a good compromise between expense, simplicity and meeting the 17th.

Chint have a CU at £33, MCBs at £1.85 and RCBOs at (what I think is a reasonable) £16.87 (inc VAT)
http://www.alertelectrical.com/Cons...t-10-way-Split-Load-Consumer-Unit-NX2-14H.asp
I've never heard of Chint before, is their stuff alright?

Cheers!

 

[333rocky333]

Pay a bit more and get a branded consumer unit.

 

[bongos]

A split load consumer unit with a 30mA RCD, on the RCD side there will be
32A MCB - Socket outlets ring
6A MCB - Lighting
40A MCB - Shower
On the non-RCD side;
32A RCBO - Kitchen sockets ring (and combi boiler on FCU)
6A MCB - 'emergency' light (a simple lamp fitting and pull-cord mounted on the wall next to the CU - no buried cables or anything.

All ok up to here.

I've never heard of Chint before, is their stuff alright?

It's all gone wrong here.

I understand that amongst many sparks they are generally considered the lowest of the low (or very nearly!)

If you're doing the work yourself make sure you know about Part P and that this would be notifiable work to your LABC.

 

[RF Lighting]

Are chint still giving away a free fire extinguisher with every CU?

 

[martinxxxxxx]

Chint rhymes with skint and seems to be an amalgamation of the two words "skint" and "cheap". These are not great concepts for choosing a CU. Why not select one for a few quid more that we have heard off and has a reputation for quality.

Maybe they are ok, maybe not. I do not really know, so I prob have not helped.

OK Martin

 

[ColJack]

think of a word that rhymes with chint ( or close to it ) and you have the general quality of their gear..

your set up sounds ok..

i take it you cook on gas? might be worth putting a cooker circuit in while you have the opportunity..

a seperate radial for the heavy kitchen equipment might be a good idea ( washer / dryer / dish washer etc.. )

 

[Spark123]

I wouldn't put lighting and sockets in the same area on the same RCD, maybe worth thinking of a 6A RCBO for lights.

 

[RF Lighting]

Spark123, could you switch your MSN on please

 

[Hibbo]

Thanks for the replies!

I do indeed cook on gas, but I am planning running a cable from the CU to the kitchen for future use. Does a cooker HAVE to have local isolation? If so I will mount a CCU and run the cable to it.

So Chint are not the way forward - cheers!

Can anyone recommend some decent brands that won't break the bank?

 

[Spark123]

Hager

 

[333rocky333]

Mk ,wylex, hagar, usually do deals of a box and breakers etc.
It may work out cheaper even if you do not use all the breakers.

 

[Hibbo]

I don't think a separate radial for Kitchen appliances is needed as the kitchen will be on it's own 32A ring.

I'm in Scotland so part-p is not an issue. Although I have passed 2391, I don't think I can certify the work myself as I'm not a member of any trade associations. I should be alright doing the work myself then getting someone else to test and certify it though, yes?

I'm not too bothered about the lights being on the RCD side, as the CU is easy to get to (by the front door) and I'll have a separate light there on the non-RCD side.

 

[AndyPRK]

put the light circuit on an RCBO so faults with other circuits which trip the rcd will not disable them

 

[skenk]

Are you re-wiring/alterations to sockets or CU change? Does your work need a building warrant?
//www.diynot.com/wiki/electrics:building_warrants

Assuming you need a warrant you should be able to do your own certificate if you're competent (small c) and BC should check your work BUT some BC's demand that the work is done and/or certified by SELECT/NICEIC scheme member (pir may be accepted). You need to call your BC and ask them what they will accept.

Whoever signs it off will need to be happy that it complies with 314.1 - 314.3 (division of circuits, minimise inconvenience etc. )

The problem with a split load is you have to use RCBO's which push the price right up. If you're planning on staying in the property for a while then you'd be better off with a dual RCD or 3-way 'high integrity' CU for flexibility in the future or to have the lights on their own RCBO.

If you're re-wiring then put put in 2 lighting circuits.on dual RCD If there is only 1 general lighting circuit then I don't put the shower on the same RCD as the lights. It's always tricky working out which other circuits to put with the lights - the one(s) with the least potential for danger/inconvenience in the event of a fault)

Wylex is a decent compromise between hager and the crap stuff if you're on a budget.

 

[Hibbo]

Thanks for the link, I'll read through the PDF later...

I am going to completely rewire the flat and fit a new CU, although the lighting circuits may have to stay as they are (I can't just pop upstairs and rip up the floorboards!) - if the cables are in conduit I may look at pulling new ones through.

I do plan to stay in the flat for a while (or rent it out when I move), so I want to do things properly.

I understand what you're saying about the lights (there's only going to be one lighting circuit), but as you say, an extra RCBO would push the price up.

Would a dual RDC CU work out cheaper than a standard split-load CU and 1 (maybe 2) RCBO? If I went this route I'd probably go for the kitchen and lights on a separate RCD to the shower and main ring.

I've found some reasonably priced Wylex kit, I'll have a look for a Wylex dual RCD unit...