Installing LED Striplight into existing modular switch panel

[David9876]

Hello



I want to install a 10W LED strip light under a wall cabinet in my utility room, with a dedicated switch, and am looking for some advice on how to connect it to my existing electrics. I’m an engineer (structural) and competent DIYer, but I’m not an electrical engineer so despite having done a lot of research on this but can't find an exact example and I’m not 100% sure of the correct solution, and in some cases may even be using incorrect terminology.

The lamp is a Robus SPEAR 620mm LED Linear Cabinet Striplight 10W 1095-1159lm - Screwfix and the instructions say to connect the live and neutral wires directly to an existing light switch. I have an existing modular switch panel with ceiling light switch, and an extractor fan which seems to be spurred from it using a 13A fuse. Only the live is going through the fuse, the neutral for the fan is fed directly from the ceiling light. Ideally I’d like to update the modular switch panel with a new one like these (MK Grid Plus 10A 1-Way Grid Light Switch White with Colour-Matched Inserts - Screwfix) to include replacements for the existing switches/fuse and an additional switch for the LED strip light.



I have a couple of questions:

• Is the existing wiring setup ok? Only the live goes through the fuse, is this what’s referred to as single pole, and if so it is ok? I think extractor fans have double pole switches in bathrooms, but as this is only a utility room is it ok being SP?
• Can I install a new module switch connected directly to ‘OUT1/2’ on the extractor fan switch, using the 13A fuse already installed? Or would I need to change the fuse to a lower amp, or wire it entirely differently?
• I’d like to avoid a separate switched FCU if possible, but would the correct solution be to connect a 3amp switched FCU to the extractor fan ‘OUT1/2’?

I’ve included some diagrams of current set up, and what I think I’m proposing for the possible solutions. Any advice would be greatly appreciated, thank you.


David

 

[EFLImpudence]

• Is the existing wiring setup ok? Only the live goes through the fuse, is this what’s referred to as single pole, and if so it is ok?

No, that is not what is referred to as single pole. Switches are single pole, double pole etc.
Of course it is ok; neutrals are not fused.

• I think extractor fans have double pole switches in bathrooms, but as this is only a utility room is it ok being SP?

Various arrangements might use DP switches but they do not usually have DP switches and of course SP is alright.

• Can I install a new module switch connected directly to ‘OUT1/2’ on the extractor fan switch, using the 13A fuse already installed?

Of course not; if you did that it would only work when the fan was on - connect it to the IN1/2 of the switch - i.e. the fuse OUT and neutral.
The fuse isn't actually necessary but should be 3A.

• Or would I need to change the fuse to a lower amp, or wire it entirely differently?

It should be 3A anyway.

• I’d like to avoid a separate switched FCU if possible, but would the correct solution be to connect a 3amp switched FCU to the extractor fan ‘OUT1/2’?

No, you don't need another fuse - just a switch on the line(live) conductor connected to IN1 but you can have a DP switch if you want .

 

[EFLImpudence]

 

[David9876]

Of course not; if you did that it would only work when the fan was on - connect it to the IN1/2 of the switch - i.e. the fuse OUT and neutral.
The fuse isn't actually necessary but should be 3A.

Ah yes of course, I don't know why that didn't occur to me.

Thanks for the feedback @EFLImpudence, all seems simple now you've given the right solution.

 

[David9876]

Hi @EFLImpudence another thought occurred to me, if I use a SP switch for the LED light do I just connect the N from the LED light directly to the IN2 of the extractor fan switch?

 

[EFLImpudence]

if I use a SP switch for the LED light do I just connect the N from the LED light directly to the IN2 of the extractor fan switch?

Yes.

 

[plugwash]

Some things to be aware of regarding the "modular switch panel".

There are many different modular accessory systems and by and large they are NOT compatible with each other. Basically each manufactuer has their own system, and some even have multiple (e.g Scholmore Click have both "minigrid" and "gridpro"). MK's grid plus is by far the best known system but it's far from the only one in use.

If you want to re-use the existing components then you will need to stcik with the existing system. If you are going to start from scratch you need to make sure you get all parts from the same system.

In addition to the modules and the face-plate, many (but not all) modular systems require a "grid frame" or "yoke". If you want to increase from 3 modules to 4 then you will likely need to replace both the grid frame (if there is one) and the faceplate.

 

[David9876]

Thanks @plugwash some sound advice indeed. I had always planned to replace the full switch array, increasing from three to four, so bought the rest of the frame and faceplate with the new switches. What I was pleasantly surprised to find was the grid frame uses standard backbox screw positions so I didn't need to change the backbox.