Virgin kitchen what supply cables?

[oldman2]

As a retired industrial sparks and it has been 30+yrs since I wired a kitchen things have changed a great deal since then, but I have this nice new shell of a kitchen and want to get the supply cables drawn in from the CU in the next couple of weeks even though I will not be doing the final circuit designs for a while yet as we dont even know what units we will fitting.

I do expect to have the following.

Cooker
Hob
Extract hood
wash machine
Dish washer
2 Fridge freezers
Kitchen sockets
Ceiling lights
Under wall cupboard lights
Outside lights

I was considering running the following cables as supplies

2 x 2.5mm for final ring
2 x 6mm (one for cooker and one spare for ? ) I have plenty of 6mm so it seemed a good idea to run another just in case.
2 x 1.5mm one for kitchen lighting and one for outside lights

I have plenty of spare RCD and non RCD ways available at the CU.

The reason for getting the cable in now is so I can get the rest of the house back to normality knowing the supplies are there and the only place Iam going to make more mess is in the actual kitchen and it will be some months yet before I can proceed with work on that.

The layout will be L shaped on just the 2 thermolite walls

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The old existing kitchen is still functional for now though I do have 4 walls that I must render up to keep the dust down in the mean time.

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[ban-all-sheds]

Which part of the UK are you in?

 

[oldman2]

The part that requires Part P Ban

Kent if it helps.

I have a building notice in force on this project and the council will be sending a contractor to inspect if thats your next question.

 

[ban-all-sheds]

It would have been, not because of any wish to be an enforcer, but clearly Building Control are involved (if not, you've got bigger problems brewing than what cables to use ), and if you'd dropped a ******* over Part P compliance you ought to know sooner rather than later.

I'd make the cooker circuit 10mm², on the grounds of "you never know" and a dislike of using diversity to justify a design where In <= Iz <= Ib.

You could use some of your 6mm² for a radial for the W/M, D/W if 4mm² won't hack it (dunno what installation method you plan), keeping them off the general socket circuit.

I'd also put the F/Fs on a non-RCD circuit, or on two separate RCBOs.

Even if you never end up doing it, put cables in place for cornice and plinth lighting.

If you don't know what's going where, but do know for sure that you'll have a line of appliances and base units along certain walls, why not put a run of galvanised trunking in - you can then tap off anywhere you like, and just have to do a minimal amount of chasing & making good where you run up to sockets & switches above the worktops.

 

[oldman2]

Yes the BCO has been paying regular visits and is happy enough up to now and aware of my delaying the wiring final design.

I know what you mean re the cooker but I will never let her have an oven taking that much current! Gas she may have

Yes the spare 6mm feed would be handy for a radial with any further cable in 4mm.

The F/Fs on separate circuits I see your thinking there.

Good call on the cornice and plinth lighting, being old school I hadnt considered that, but I bet the wife may.

Why Galvanised trunking? I would have thought plastic would have done in that situation and been easier to get out of without the need for grommets. Trunking along the 2 walls is def a good thought though.

Cheers Ban.

 

[ban-all-sheds]

It might be easier to punch 20mm holes in in-situ galvanised trunking than trying to do a neat job of cutting PVC.

Plus you could then use metal conduit for all the drops on circuits where you want to be spared all that RCD malarkey...

 

[Chri5]

Galv will need earthing, and is a bit OTT. If you used it, you might as well run the verticals to boxes in galv conduit.

Consider feeds for the venting / extractor fan, if you plan a w/mount TV then power and co-axial feeds will also be sensible.

Centralised switching above counter on a bank of MK grid switches is popular, and with bare walls is easy to plan in, all the under counter appliances- dish washer, tumble drier, washing machine, waste disposal etc together saving the walls from x number of individual boxes and switches / fused spurs.

Sockets and switches, inc the oven / cooker isolation should not be located in the cooker heat zone.

 

[oldman2]

Thanks Chri5, I think conduit reminds me of my past too much, would like to steer clear of that if I can. The 2 CU's I have are up to 17th so I dont have a problem with RCD's or not and I have enough spare ways on both I think, though the list is getting longer

I had planned for an extract system, I have a spare Ventaxia ACM 100 which I would like to use.

TV coax I hadnt planned for but can easily enough.

As to the centralised gridswitch block, I was wondering if I need to bother at all with above counter isolation?
I took this quote from a contractors site.
"Sockets for equipment below the worktop

It uses to be common to see rows of double pole switches and switched fused connection unit above the worktop that were to control equipment that was beneath. The equipment would have a socket set in the wall behind it and impossible to get at.

The way that we prefer to provide power to equipment below a worktop is to site a socket outlet within an adjacent cupboard, and then have a hole cut in the side of the cupboard to allow the plug to pass through. This way you can get to the socket for maintenance, without having to lift out the equipment which at times can be all but impossible to do. It also means that the plug is not squashed by pipe work or vulnerable to damp from leaking pipes."

Comments...

 

[ColJack]

each to their own, but having to drag out armloads of cans or pots and pans from a cupboard when the washer throws a weight off and starts trying to escape from under the counter is a pain..
with a washing machine, the "adjacent cupboard" is also likely to be the one under the sink where the water and waste connections are, so it hardly removes the hazard of leaking pipes as they claim..

 

[Chri5]

Switches are required for emergency isolation- fire etc

Have them accessible minimises the danger. Imagine a smoky dish washer , fumes a plenty and there is your wife attempting to isolate the device by hunting in a cupboard full of miscellaneous pots, pans, tins etc.

Not the best idea or design, they MUST be accessible.

 

[oldman2]

Yes you are both right, MK grid switches would seem the reasonable way without the clutter of many switches spaced along the worktop.

Thanks again.

 

[RF Lighting]

The way that we prefer to provide power to equipment below a worktop is to site a socket outlet within an adjacent cupboard, and then have a hole cut in the side of the cupboard to allow the plug to pass through. This way you can get to the socket for maintenance, without having to lift out the equipment which at times can be all but impossible to do. It also means that the plug is not squashed by pipe work or vulnerable to damp from leaking pipes."

Comments...

Sounds pretty typical of a kitchen fitter.

I have just finished a kitchen for a family member.

I installed a 16A radial for the oven / extractor hood. 2G grid switch above the worktop to control them. Steel conduit in the wall to keep them off RCD.

A 32A radial in 6.0mm² to a 32A DP isolator above the worktop for a 7.5kW induction hob. I could have got away with 4.0mm² for this, but it leaves some room for future expansion. Steel conduit in the wall to keep them off RCD

A 32A radial in 4.0mm² to a 3G grid switch for the washer, dishwasher and dryer. Steel conduit in the wall, and sockets below the worktop in surface mount mini trunking. Also, engraved sockets to keep them off RCD.

A 16A radial for the fridge freezer. Yet more steel conduit in the wall to keep it off RCD.

General ring circuit on a 32A RCBO supplying 6no. twin sockets above the worktop. This ring also supplies the living room sockets.


General socket, cooker & hood switches, hob switch:

Appliance switches:

Sockets under worktop:

 

[securespark]

Sorry, Rob. That's just not good enough. Redo it immediately. I think you're a milli or two out here and there.

 

[londonboy]

RF I gotta ask, did you use switched sockets for a reason? Also do the appliances still go all the way back or does the plugs restrict them.

Not picking holes its just things I've had problems with in the past!

I like the gridswitch idea, I might use that on the next kitchen I do.
Where did you find the engraved modules?

 

[RF Lighting]

No real reason for using switched sockets, other than they were in stock at Enlabel (the engravers)

The washer and dryer are both about 520mm deep, and the worktop is 600mm deep, so no problems there.

The dishwasher is 600mm deep, so I put all the sockets behind the washer and dryer. The dish washer can still be unplugged with out pulling out the washer.

The engraved switches are from MK. They are standard switches from the grid plus range, but will normally be special order from most wholesalers.

The plates are from the MK edge range. These are quite expensive, but look the part.