Kitchen Wiring - Help/Advice needed

Hi There, Been reading up on quite a few threads on this forum, you all seem like pretty helpful guys so thought I would post for some thoughts on my current kitchen thinking.

We are going to be re-doing the whole kitchen complety so re-wire required here, so I need to make sure we have planned it all correctly :-)

Sockets We are going to have all integrated appliances, and I have been reading up on ways to wire up, FCU above worktops etc, we plan to surface mount double sockets in the units adjacent to the appliances to plug them into. This is to minimize all the switches we will otherwise have above units. The switches to the appliances are then accessible after moving a few tins of beans, so can be shut off immediately in an emergency.

Also part of this ring will be the sockets on the wall above worktops. So on this ring we will have :-

4 dbl sockets for small appliances (ie toaster, kettle) in cupboard sockets for Fridge/Freezer, Freezer, Dishwasher, washing machine, Gas hob (power for sparker), Oven as it rating is Max Rating: 2.35 kW Fuse Rating: 13 Amps(sparky told me can go on main ring and not need a separate supply) and the extractor. Will this be acceptable or should it be split into 2 circuits?

The boiler which is in kitchen has a separate radial circuit with one socket at the end of it.

The lighting is where I have my major headache, currently we have one very large strip light, infact looks like 2 stuck together, you should see how long it takes to come one after switching switch!! The plan for lighting is to

1) replace strip light with a none offense light, perhaps a four way spot light. 2) Fluorescent tubes over wall cabinets for extra light 3) Under counter fluorescent lighting 4) Kitchen has a recess so we are lowering ceiling and putting spotlights in there.

Now it is a flat I live in, so gaining access to lighting is tricky and I think not a good idea to put any more on circuit, as all rooms are on one circuit ( 6 light fittings). Also the wiring is a bit peculiar, not anything I have read about! The power comes from CU, into a metal box, in metal box, about 6 T & E wires are twisted together, i.e. reds all twisted together etc. Then each wire goes to the switch in each room and out the switch comes feed to light, so switch off, cable would be dead. So the neutral cables in the light switch boxes are twisted together and not in any connection.

Anyway we have a spare breaker in fuse box, so was wondering if it would be a good idea to create a new light circuit for lights 2,3 and

4 in the kitchen. The under and over counter lighting is what I am unsure of here, I would like a switch for the over and one for the under and one for recess, ideally all in one grid switch to keep it neat. The kitchen will be u shaped but has a gap at the top of the U in units due to a window, so cannot just connect lights all the way round, using the nice connection cables that you can get. The lights will just be on the two opposite walls.

What is the best way to link up these fluorescent lights, and have them controlled by one switch each, can I just start at one end connect lights, then run a T&E to the lights at other side, putting cable under floor, then end that set at other side of kitchen?

Thanks for any advice, and cries of NO DON'T DO IT ;-) Rather that, than get blown across the room :)

Reply to
inNeedofHelp
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Well, I would not be happy having all this on one circuit, even a 32A ring. Also, it doesn't allow for RCD protection.

I would at least divide into 2 circuits.

  1. NOT RCD protected for fridge/freezer/dishwasher/washing machine/oven/hob.
  2. RCD protected for everything else.

Personally, in a similar situation I have 3 circuits.

  1. 16A MCB radial for fridge/freezer only.
  2. 32A MCB radial for washing machine/dishwasher/tumble dryer.
  3. 32A RCBO ring for sockets and the oven.

There's no particular reason to have the oven on the RCBO circuit, except that it is actually now quite underloaded, so has plenty of spare capacity. The oven is (or at least will be) only the 2nd oven in the cooker. The main oven and grill is gas. I prefer to have the fridge on a separate circuit to avoid the consequences of the circuit tripping. At least if it trips, we know it was the freezer or associated wiring at fault, not some fault elsewhere.

Just avoid the spotlights, as they are inefficient. I've got a couple of flush fittings in the ceiling, which take CFLs and underpelmet fluorescents. This is plenty of light. Make sure they are switched separately from the ceiling lighting.

All sounds fine, apart from the twisting together. It is perfectly acceptable in a circuit design sense, it is just that the connections are insufficiently secure.

Don't worry about providing a new light circuit until you've added up all the usage on your current one. Also, if you avoid SES or SBS fittings and only have standard light fittings (plus any LV halogens/fluorescents etc), then you can usually increase the MCB to 10A.

Yes, just connect them all together with T&E and connect that T&E to the light switch, assuming you will maintain the method of looping the neutral at the switch.

In some ways, as you are using light switch looping and grid switches, consider using 20A DP switch modules and having DP switching on your light circuits. That will be slightly safer, especially in the event of using ES fittings.

Christian.

Reply to
Christian McArdle

"inNeedofHelp" wrote | This is to minimize all the switches we will otherwise have | above units. The switches to the appliances are then | accessible after moving a few tins of beans, so can be shut | off immediately in an emergency.

I'm not sure but I think cooker control units have to be visible; they certainly should be within 2m of the cooker.

You can cut down on the number of switches by wiring as a radial circuit and having a gridswitch panel with a number of 20A DP switches on one faceplate.

| in cupboard sockets for Fridge/Freezer, Freezer, Dishwasher, washing | machine, Gas hob (power for sparker), Oven as it rating is Max Rating: | 2.35 kW | Fuse Rating: 13 Amps(sparky told me can go on main ring and not need a | separate supply) and the extractor.

Bear in mind that double 13A sockets are not rated at 26A, and if you concentrate oven/dishwasher/washer you may have an unacceptably uneven distribution of load around the ring.

| Will this be acceptable or should it be split into 2 circuits? | The boiler which is in kitchen has a separate radial circuit with one | socket at the end of it.

If the boiler is connected by plug and socket it must be an unswitched socket. This is to ensure the plug is pulled to provide DP isolation.

Owain

Reply to
Owain

I would still put the overn on a seperate cb and cable from the CU, This is so it can be switched off when the grill catches fire !! and also less upheval should you go all electric

Reply to
James Salisbury

Nice idea.

I found places for soclkets and switches behind the units. If there is a major problem I just kill the whole ring and fix..

I prefer to lightly load rings, but it seems accepatble to me.

Good idea. Put in lots, and put in seperate wires for evertything, as you may want to differentially swith or dim later on.

Bite teh bullet and fit yourself

- a cable from consumer unit to kichen for ALL lights.

- a decent juncton box in teh wall or a cupboard or something

- separate wires from this to every independently controlled light

- as few cables (live/switched live pairs?) from this to the grid switch as is possible. That is don't carry either the lighting wores or any netrlas to teh switch if its big. Do all the neutral commoning and earth commoning in the junction box.

I should have done his in my kitchen, and didn't, and the 3 way switch is a rats nest as a result.

- e> Thanks for any advice, and cries of NO DON'T DO IT ;-) Rather that,

Reply to
The Natural Philosopher

NO! unless the whole house is RCD protected by 100mA. You MUST have a trip on the appliances as these are he most likely things to develop an earth leakage problem. Agreed this is not normally a shock problem unless the metalwork gets de-earthed by e.g. corrsion.

Ive got it another way, single 32A protected on house 100mA for all sockets and applinaces

Single 45A for cooker, agreed its a full leccy cooker.

I would NEVER run any metal cased appliance without some form of RCD. Loose earth wire and then a fault and your dead.

Ideally I would have one ring for appliances (below counter) and one for sockets (above counter) with RCBO on each...

Reply to
The Natural Philosopher

"MUST" is a bit strong. There is no requirement in the regs to RCD protect such circuits. If safety is your concern, the 40 quid additional cost of the RCBO would be better spent elsewhere, like on additional fire extinguishers or an escape ladder, or non-slip paint for the door step, all of which are far more likely to save you from harm than the slight possibility of a double fault occuring in an appliance whilst you are clamped to a good earth in the kitchen.

It also strongly increases the risk of a nuisance trip taking out the fridge/freezer.

Christian.

Reply to
Christian McArdle

So it would be more prudent to split the kitchen into 2 circuits and then would I run my extra lights of the lighting circuit, or some could come off ring. Altough this then means I have a nasty FCU box to put somewhere.

Would you suggest a connection block or j-box here then?

Could you elaborate here? Why are DP switches better and what is ES? Over my head here a little, more reading required.

Reply to
inNeedofHelp

DP switches switch the neutral as well as the phase. If you're going to use a grid switch and light switch looped neutrals, the additional neutral connections in the switch modules may actually make wiring easier, as you aren't trying to stuff loads of neutrals in one loose and poorly insulated connector.

The DP grid switches will have live+neutral supply and live+neutral load. Simply connect the output lighting cables to the load terminals and connect all the supply lives to each other (and the incoming circuit cable) and all the supply neutrals to each other (and the incoming circuit cable). No terminal (except your earth block) will need more than 2 cables inserted. Each of the T&E live conductors (phase or neutral) will need to be cut the same length (the earths will probably need to be longer), making installation easier.

+----------+----------+-------- to circuit live | +----------+----------+------ to circuit neutral | | | | | | +-L-N-+ +-L-N-+ +-L-N-+ |Supp.| |Supp.| |Supp.| | | | | | | |Load | |Load | |Load | +-L-N-+ +-L-N-+ +-L-N-+ | | | | | | | | | | | | | | | | | | To light To light To light 1 2 3

Earths omitted for clarity. Switches 2 and 3 will have 2 T&E on the supply side.

ES = edison screw. Miswiring in the lighting circuit wiring may make the outside terminal live, when it should be neutral. At least with DP switching, when the light switch is off, you know that the accessible outside terminal is dead. This benefit is very minor. The main reason I suggest DP switching is that it can make wiring simpler when you have switch looped neutrals.

Christian.

Reply to
Christian McArdle

Thanks for clarifying that :-) I was having another look at the lighting last night, to work out if current circuit would take our intended lighting. Our lighting circuit is running on a 16A MCB, I expected it to be 5/6 maybe a 10A. Is this

16A MCB ok to leave for the lighting circuit?

A few people have suggested it may be prefferable to put the kitchen on two circuits. I was wondering if the boiler circuit which runs through the kitchen could have some other appliances added to it.

Currenlty boiler is on a radial circuit with one dbl socket at the end, on a 16A MCB. Any reason the boiler needs to be on its own circuit? Could we extend this one to put some other appliances on, so to create 2 kitchen circuits.

Reply to
inNeedofHelp

No, reduce it to 10A. Most light switches and fittings are rated for that value, except SBC and SES fittings, which are 6A.

There isn't much diversity left on a 16A radial. I might consider reuse for the fridge/freezer, but not for major heating appliances like washing machines, dishwashers or ovens, unless you can fit with 100% allowance. (i.e. 3A for CH and 10A for a 2kW oven would be OK).

One alternative if it is run in 2.5mm cable (which it might not be, so check), is to complete a ring with it back to the CU and upgrade to a 32A MCB. This could then be used as a non-RCD circuit for fixed appliances, leaving the other kitchen ring as an RCD protected portable equipment socket circuit. Ensure the CH runs off a 3A FCU, though.

Christian.

Reply to
Christian McArdle

Surely it would also be ok to use a DP switched socket then? They're pretty universal these days with SP only saving a few pennies at the extreme budget end of the market...

Then I suppose there's the question of whether it'd be best to isolate the boiler from the circuit earth when working on it...

Hwyl!

M.

Reply to
Martin Angove

On the average copper plumbed house this would probably be impossible.

Reply to
Tony Bryer

Isolation doesn't require breaking the earth connection, just the live and neutral.

Reply to
Andrew Gabriel

"Martin Angove" wrote | "Owain" wrote: | > If the boiler is connected by plug and socket it must be an | > unswitched socket. This is to ensure the plug is pulled to | > provide DP isolation. | Surely it would also be ok to use a DP switched socket then? | They're pretty universal these days with SP only saving a few | pennies at the extreme budget end of the market...

The point is that if a switched socket is used, it is not apparent to Mr Boiler Man whether it is SP or DP. The possiblity remains that Mr B M will switch off at the socket, thinking it is DP, when in fact it is SP. Using an unswitched socket ensures the plug will be pulled (or of course an FCU which are always DP AFAIK)

Owain

Reply to
Owain

THis is what I thought, thanks for confirming that. I take it I just straight swap the MCB for a 10A. After totting up current usage should still be well within max load, thankfully.

Great this is the news I wanted to hear, this means I can run 2 rings in the kitchen and still have a spare MCB in the CU :-) Giving the option to put all the new lights required in kitchen and recess on a new circuit.

Even if cable is not 2.5mm we can replace this no problem, and then have sat wahsing machine etc and boiler all on that. A lot of people go with the all fixed appliances on one ring and sockets on another, but I was wondering would you not be better doing a 50/50 between both rings. i.e. some fixed appliances on each ring to spread out the high load appliances??

Also the CU we have is not a split RCD/non RCD type its a new box, but just a 100A main switch, and 6 MCBs. SO I guess both kitchen circuits will be non RCB.

The FCU for boiler, I presume should be a switched one?

Think I may have a look for a good wiring book, my DIY book is pretty useless, but does have nice pics ;-) Any recomendations?

Thank you so much for advice/info.

Reply to
inNeedofHelp

One problem is that high load appliances can unbalance a ring, if they're not distributed around it. If you are able to rewire the entire circuit, it may be worth doing the ring in 4mm, or even to run a radial circuit in 6mm cable. This way, any imbalance doesn't matter as you are unlikely to overload one leg.

I still think putting just a kitchen onto its own lighting circuit is a bit of a waste of your last remaining spare MCB. However, I can't complain, as I did exactly this for mine. This had more to do the fact that the existing house was all off one circuit and I promised myself that I would eventually distribute the load over 2 circuits. Not that I ever will. OTOH, I have 4 spare ways, still.

Someone may have switched it to prevent the MCB tripping when a bulb blows. A safer solution would have been to use a 6/10A Type C. Better still is to not use incandescent lightbulbs, but have CFLs exclusively.

The portable socket MCB (and the MCB for non-kitchen sockets) should be replaced by a single width RCBO B32A/30mA. The fixed appliance MCB should remain.

Christian.

Reply to
Christian McArdle

You should find that you 'will / should' get two by 4mm conductors in the terminals of a standard 13Amps' socket, but I think you'll find that two 6mm conductors are far to big to fit. Most manufactures make the terminals 9mm in diameter, so 12mm won't fit unless you tear some strands off, but that's a really silly idea so don't do it.

Reply to
BigWallop

Sorry. I omitted the smiley.

;-)

There. Is that better?

:-)

Hwyl!

M.

Reply to
Martin Angove

I'd have thought it more likely the other way around:

Boiler engineer who does this sort of thing for a living will always unplug the boiler rather than assume the socket is DP switched.

Householder who thinks the internal fuse in the boiler may have blown and wants to DIY without calling in a boiler man (or other similar situation) may merely switch the plug off without thinking. A DP plug is then as safe as a non-switched plug or an FCU.

Hwyl!

M.

Reply to
Martin Angove

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