Wiring for lights under kitchen cabinets

[john4703]

I’m planning to renovate my kitchen, the walls are in a bad state and I will replace the old lath and plaster with 18mm ply to give good solid walls that are easy to fix units to.

I plan to run plastic conduit behind the ply for all circuits, keeping the conduit in safe zones. I’ll probably use 35mm metal back boxes for all switches, sockets etc

The thing I am stuck with is the wiring to the lights under the units. I want plenty of light onto the work surface but am not sure what is the standard method, or best method of getting cables to theses lights. (In the existing kitchen there is a 1.5mm t&e supply that emerges from the wall a few centimeters below the bottom of the upper units. I am sure there must be a better way but I’m unsure what it would be so would appreciate your advice. I think that using conduit future proofs it as I can run ELV or LV now and it could easily be changed in future. I’m in a top flat so the conduit will go up into my loft.

Any recommendations for good under cabinet lights would help, I am sure I’ll use LEDs as I hate the existing fluorescents that have aged to be different shades of light.

I’m doing the wiring myself. I changed the consumer unit last year and have enough RCBOs fitted to supply the lights, ring, oven and hob.

 

[EFLImpudence]

Connect them to the lighting circuit which will be available in the loft.

If 230V - cables can be run to all the points however you want.
Not really any point but - if 12V then cables can be run to wherever you want the power supplies.


I shall ignore your last line, others may not.

 

[john4703]

Thanks ELF I will use a new circuit for the kitchen lights, probably the same as the bathroom as it is RCBO protected. The existing lights are still on a MCB as the regs do not require existing circuits to be RCB protected (as far as I know).

My real question is how should the cables come out of the wall under the units? Should there be a box, not nice looking but I dislike the existing which is a rough hole in a tile. (When I served my time such luxuries as under unit lighting was unheard of).

I am pretty sure that in Scotland I can legally do this wiring myself.

 

[EFLImpudence]

Thanks ELF I will use a new circuit for the kitchen lights, probably the same as the bathroom as it is RCBO protected. The existing lights are still on a MCB as the regs do not require existing circuits to be RCB protected (as far as I know).

Only new work must comply with the latest regulationss - in England.

My real question is how should the cables come out of the wall under the units?

It can just come out of the wall behind a unit and run down to the light discretely. Depends where your lights are mounted.
You mention 1.5mm² above, 1mm² T&E will be far more than adequate.
You could use smaller white flex if any of the cable will be visible below the units.

Should there be a box,

Not necessarily.

not nice looking but I dislike the existing which is a rough hole in a tile. (When I served my time such luxuries as under unit lighting was unheard of).

That's up to you to design it to look nice.

I am pretty sure that in Scotland I can legally do this wiring myself.

I don't know about Scotland.

 

[john4703]

Thanks again ELF that answers many of my questions and does help.

 

[SimonH2]

When my mate was doing up his bungalow, I put a plaster box in the wall just above the top cupboards, with conduits going up into the loft and down. Note that this was just before the 2005 Building Regs update making the work notifiable
Downwards, one conduit went right down to underneath the bottom cabinets for the plinth lights - in this case a T&E fed 240V down to a 12V PSU tucked behind the plinth.
Another conduit went down to a smidgen below the bottom of the top cupboards, and I stuffed some ali foil up the end to a) stop the plaster going up it, and b) provide something to search for with a detector. As it happens, I've never needed to use a metal/stud detector to find the end (so I don't knwo if it actually works) - taking measurements (height from ceiling or floor) and a spirit level have always been enough. You then need to dig the end out when plastering is done, and carefully notch the top of the tiles or splashback to leave the hole accessible. You can then feed 240V down the conduit, or you can hide a power supply on top of the cupboards and feed (eg) 12V down - taking a flex out from the plaster box to feed the supply.
You can also come out of the plaster box to feed a supply for over cupboard lights which my mate installed.
For all options, you can feed the circuit(s) down to the plaster box which you use as a junction box before feeding them onwards.

As it happens, the kitchen fitters announced they couldn't use the conduit - they were using 350mA lights (constant current, wired in series) and needed multiple connections. They "weren't able" to do anything but use the premade plug in cables. The fitters cut holes in top and bottom of each cabinet where a light was to be put, and the cables were fed up behind the false backs of the cabinets.