New Extension wiring question.

[cjsparky85]

I qualified as an electrician a few years back (not Part P), but decided to pursue other avenues so am a little out of touch on the regs and have a few questions if someone could help. My sister has had a new extension built, it will consist of a kitchen one end and a dining area at the other.

Firstly I'm aware anything to do with a kitchen needs to be notified, and tested etc. I only left a feed here as they aren't too sure how the Kitchen will be, but over the weekend her brother-in-law has run these electrics and there seems to be switched spurs for everything. One for the timer on a double gas oven...which is just a little digital clock, one for the hood, one for a washing machine and one for a tumble dryer. Is that overkill? When I was doing flats etc, the company used one switched spur that fed 2-3 sockets housed within cupboards, under the work top...with a point for an electric oven run separate.

I have however ran a socket in the dining end with a view to connecting it to circuit in the living area as it is only one outlet. I was of the belief this wouldn't need to be notified? Also with the lighting I ran cables for two lights one Kitchen end and one Dining end, as well as one light switch point that will house two switches. I wired this back to the existing lighting, does this need to be notified?

Any help would be great.

 

[SirKit Breaker]

If the extension had planning permission, then you dont need to notify it. Planning consent covers all parts of the building regs, and so any electrical work done on the extension is notifed as part of it. You will however need to ensure it complies with the 17th edition, and building regs, as you will need to issue an Electrical Installation certificate for the work, and the building inspector will want a copy before he will issue a completion notice.

I have just re read your post. All the cables you have installed will need to be RCD protected, including all the various spurs you describe (which i cant comment on because i cant see the install). If you are joining into existing circuits, then those circuits will need RCD protection or you will have to provide it for the extended part. you really need to look in the regs, because i could go on all night with the do's and dont's. But whatever you do , don't certify it compliant if it isn't, cos if something goes wrong then the **** will hit the fan and all land on you.

Cheers........Howard

 

[telectrix]

howard, you have raised an interesting popint i will pm you.Tel.

 

[cjsparky85]

Little more info.

There is only one lighting circuit, as it is a bungelow and I was simply going to come off the last JB Box. It is protected by an RCD, as is the ring I was looking to extend to include the dining area socket.

The current kitchen has a circuit protected by an RCD, my intention was to connect the new kitchen ring via the existing JB Box.Once the old kitchen was removed but my sister's brother-in-law who is a builder has stated it needs a new circuit direct from the board rather than picking up off the feed for the existing kitchen.

As for the switched spurs they are all on the kitchen ring, with feeds for seperate sockets for tumble dryer, washing machine etc.

 

[telectrix]

i would prefer the washing machine, tumbler, dishwasher to be fed through 20A double pole isolators, rather than FCUs, unless the FCus are double pole. reason..... if a N/E fault develops whilst client is away, RCD would trip. D/P isolation solves this problem

 

[SimpleSimon]

And also yes it would be best to run a separate kitchen ring back to the board. Kitchens can sometimes draw alot of current from their various appliances and so even though your in a bungalow you wouldn't want to overload your ring. But thats personal preference without seeing the design.

 

[mickytuff]

if you used double pole isolaters instead of s/f/spurs then you wouldnt have fused protection local to the appliance, would u???

 

[telectrix]

you don't need it. they are just then applianves on a ring final, protected by the 32A MCB. the reason we fit isolators is so as to be able to isolate the appliance without having to pull it out to unplug. have you ever tried moving a washing machine full of the wife's knickers and water. it's friggin' heavy.

 

[SimpleSimon]

So your protection would be at the appliance plug top and you can still isolate at the switch.

 

[mickytuff]

i see what u mean, your still complying to code, because you are still isolating the supply locally.

 

[SimpleSimon]

i would prefer the washing machine, tumbler, dishwasher to be fed through 20A double pole isolators, rather than FCUs, unless the FCus are double pole. reason..... if a N/E fault develops whilst client is away, RCD would trip. D/P isolation solves this problem

Tel. I've been thinking bout this all week. Why would D/P isolation stop a N/E fault tripping RCD? Can't get my head around it.

 

[Des 56]

Example
Washing machine permanently plugged in at rear,neutral earth fault on machine that may not have been apparant,leaking water, damp building up etc whilst on hols
Washing machine switched off using single pole fused spur above worktop
Single pole isolation will not disconnect the faulty neutral from earth,other circuits like a fridge still in use may use that path for its return,rcd imbalanced trips out,freezer off, food smelling bad when owner gets back home

 

[SimpleSimon]

Got it. Cheers Des