Kitchen

[wiggles]

We are having a new kitchen installed shortly. An electrician will be doing the wiring. We are going to have quite a few high current appliances. Oven, microwave, dryer, dish washer & washing machine as well as the usual low consumption devices like fridge/freezer etc. All of these appliances are built in. I don't know the rating of all the appliances yet, but I know that the oven is the type that can be plugged in so it must be under 13 amps.

The oven and microwave are together, so I'm thinking they could share a radial wired in 4mm on a 32amp mcb. The dryer and dishwasher are also together so they could also share a radial wired in 4mm on a 32amp mcb. That just leaves the washing machine as the only high current device and low current devices (like the extractor fan) which could run from the downstairs radial. The above bench sockets in the kitchen could also use the downstairs ring.

Does this seem a reasonable solution? There are two spare ways on the RCD side of the CU to support these new radials.

 

[ub9533]

Hello
If your doing two radials i would join them and make a ring main and put them in the board on the rcd side with 32 amp breaker marked kitchen. I wouldnt put a 4mm cable radial on 32 amp breaker i would use 20 amp.

 

[ColJack]

Hello
If your doing two radials i would join them and make a ring main and put them in the board on the rcd side with 32 amp breaker marked kitchen. I wouldnt put a 4mm cable radial on 32 amp breaker i would use 20 amp.

really? so instead of having 64A capacity for running high current equipment you'd limit him back down to 32A?
4mm is perfectly acceptable for a 32A radial ( assuming it's not run in insulation etc. ), and is the common way they do it in most other countries..

OP, your setup sounds reasonable, but I think I'd keep the kitchen ring seperate from the downstairs ring..

as the sockets for the WM/DW etc would generally be behind the items, then if you can satisfy the requirements to not RCD the cables, there is no need to RCD the sockets ( just fix a lable to them saying what they are for.. ).
you will need above counter switches for the WM/DW etc.

you missed out the big current little stuff that could be used on the ring such as the kettle, toaster, panini press, george forman grill etc....

 

[ub9533]

HAHAHA ColJack odviously you are no electrician!! As for 64 amp capacity most domestic house dwelling are only 60 amp supplied. Most houses are wired with 2.5mm socket ring mains with upstairs downstairs or kitchen and house. Also all sockets either radial or ring main should be on RCD as to 17th edition regs .Wiggles do a ring main don't put a socket behind a integrel appliance or it wont slide all the way in put it in the cupboard next to it off of a switch fuse.

 

[wiggles]

Thanks for your replies guys.

Just to clarify, I won't be doing anything - the electrician will be doing it all but I want to be sure that a proper job is done.

As ColJack identified, the whole purpose of using 4mm and 32amp mcb's was to get away from being limited to 20 amps at each circuit. Each circuit would draw approx 26 amps, not the full 32.

If the circuits were on 20 amp mcb's I'm going to spend a lot of time wandering into the garage to reset them

Coljack, regarding the portable high current devices, basically it's only stuff like TV's that are plugged in elsewhere, so we might as well call it the kitchen ring anyway.

I've also been told that above bench switches are not required for the appliances - I'm in favour of them though as I don't want to have to empty the cupboard just to switch off an appliance when it burts into flames. I was thinking of a couple of nice neat grid switches. Also, I'll sleep better at night knowing they are all turned off.

 

[ub9533]

if you have electric hob don't wire that with 4mm

 

[wiggles]

No electric hob, no electric shower. House on a 60 amp fuse. I could ask the DNO to change it but I can't see it being an issue?

I suppose I could get the electrician to leave new tails for the DNO to connect? Is it free to get upgraded to a 100amp fuse?

 

[Steve]

HAHAHA ColJack odviously you are no electrician!! As for 64 amp capacity most domestic house dwelling are only 60 amp supplied. Most houses are wired with 2.5mm socket ring mains with upstairs downstairs or kitchen and house. Also all sockets either radial or ring main should be on RCD as to 17th edition regs .Wiggles do a ring main don't put a socket behind a integrel appliance or it wont slide all the way in put it in the cupboard next to it off of a switch fuse.

HAHAHA Prat.

I'd far rather have two radials in a kitchen. The kitchen is where most powerful portable appliances are.

My house has 100 amp service. As do all my neighbours.

My house has upstairs, downstairs and kitchen ring mains. Thats 3. Count em 3.

And whos to say a 60 amp fuse will blow when the two kitchen radials are loaded to capacity? It'll take 80 amps for a long time! And they'll rarely be loaded to capacity either.

Dont go insulting regulars on here.

 

[Lectrician]

I am an 80 amp service and doubt I ever get near to this.

If folk regularly maxed out their supplies, their monthly DD would be hideous.

 

[RF Lighting]

HAHAHA ColJack odviously you are no electrician!!

ColJack may be or may not be an electrician, but at least he understands how to design circuits, and the regulations concerning this, which it would seem you do not.

As for 64 amp capacity most domestic house dwelling are only 60 amp supplied.

Most houses I work are supplied with either 80A or 100A, and even so, that is irrelevant anyway.

Most houses are wired with 2.5mm socket ring mains with upstairs downstairs or kitchen and house.

Most houses have old wiring which was not designed for today's power hungry appliances.

Also all sockets either radial or ring main should be on RCD as to 17th edition regs

That in incorrect. Have a read of regulation 411.3.3. (b)

Wiggles do a ring main don't put a socket behind a integrel appliance or it wont slide all the way in put it in the cupboard next to it off of a switch fuse.

Depends on the appliance. Most will fit back even with a socket behind them.

Oh, ond the circuits you were referring to are called ring final circuits, not "ring mains"

 

[wiggles]

Have double checked and main fuse is 60 amps. It may have been acceptable in the 80's but not in the power hungry 10's.

So it seems the radials get the green light, that leaves two questions:

1. Is it acceptable to have issolators for applainces hidden in cupboards.
2. Is 60 amp supply ok or do I need it upgraded.

Cheers and thanks for help so far.

 

[JohnnyG]

2. Is 60 amp supply ok or do I need it upgraded.

Cheers and thanks for help so far.

A 60a fuse might still be ok but that depends on the maximum demand of the installation, which is subject to many factors.
In my (limited) experience your supplier will upgrade the fuse & meter tails (if neccessary) FOC, contact them and enquire about it, if it's free go for it all, if it's at cost, go for what's required for your installation

 

[RF Lighting]

The great isolators debate has been had enough times on here!

Personally I think they need to be readily accessible. I normally just put in a matching grid switch in line with the sockets above the worktop.

As for only having a 60A supply, I really wouldn't worry. I'll bet you a quid you will never have a problem with it.

 

[Spark123]

As far as I am aware if the appliances are fixed then they should have an accessible means of isolation.
If they are free standing they don't need it.
Also another point is not to use double sockets for two power hungry appliances as I have seen them melt! Better placing a single behind each appliance.

 

[wiggles]

Hi RF,

Grid switches were exactly what I had in mind. Personally, I think they have to be easily accessible as the CU is in the garage, so it's not like I can just reach around the corner to switch something off.

It's not a problem that one grid switch may switch from more than one circuit supply is it? I'm thinking 2 switchs would switch loads on the radial and 2 switches would switch loads on the ring - all would be contained in a single 4 switch grid if possible. The alternative would be a two switch grid on either side of the socket which would not look quite as nice.

What options are there on what can be siwtched? I'm thinking the grid switch could switch an unswitched socket or an unswitched FSU - is there any other way it could be done using grid switches? The electrician did mention something about male and female trailing sockets but I don't know what he's on about.

Cheers.