Concealed cable to light switch

[Cam Black]

I am planning the addition of a light in our 'L' shaped garage. The existing light currently illuminates the main part of the garage and I wish to set up a work bench area in the other part which will need better illumination.

I would like this light to be switched separately and the sensible location for this switch is in the partition (stud) wall (utility room behind).

All existing light and power cabling is concealed and I would rather the cable to the new switch is also concealed. I have easy access from above to the existing light circuit and top of the partition.

We do not have RCBOs in the consumer unit so the circuit is not RCD protected. The consumer unit will be replaced when major kitchen refurbishment takes place later this year.

The cabling to the switch will be in safe zones but not RCD protected. My understanding of the regulations state that in this situation the cable to the light switch must be mechanically protected in earthed steel conduit or utilise SWA type cable.

Is this correct?

Apart from surface mounting what is the most cost-efficient way of complying with the regulations for a short drop of cable to a switch?

Thanks in advance
Cam

 

[EFLImpudence]

The cabling to the switch will be in safe zones but not RCD protected. My understanding of the regulations state that in this situation the cable to the light switch must be mechanically protected in earthed steel conduit or utilise SWA type cable.Is this correct?

Yes, and you can get cable which has a metal shield cover which would also comply.
http://www.batt.co.uk/products/view/306/Guardian-Ali-Tube/LSZH-Cable-BS8436

Apart from surface mounting what is the most cost-efficient way of complying with the regulations for a short drop of cable to a switch?

You could fit an RCD to just the light circuit.

 

[Cam Black]

Yes, and you can get cable which has a metal shield cover which would also comply.
http://www.batt.co.uk/products/view/306/Guardian-Ali-Tube/LSZH-Cable-BS8436

Ok thanks EFLImpudence. Would any BS8436 approved cable be acceptable? I fear it will be difficult to find such cable at the short length required (2m!). So knowing that is the standard I need will aid my search.

Does this cable need special termination/glands, earthing, metal back boxes? I assume it is self-earthed via the E core, can it be used with a standard plastic dry-wall back box?

You could fit an RCD to just the light circuit.

Definitely an option, but with the CU being replaced with one fitted with RCBOs later this year, it is an extra expense and in the longer term unnecessary.

Thanks again.

 

[endecotp]

If you're really going to replace the CU soon, just ignore this aspect of the regs for now.

 

[Cam Black]

If you're really going to replace the CU soon, just ignore this aspect of the regs for now.

Sshhhh I agree that option is the 'real world' and most cost-efficient alternative and that time is only 6 months away. But I always try to ensure that any DIY work done by me is compliant, hence my original question.

The fact that I have everything I need to do the job all sitting there ready to go just makes it frustrating.

I know that my house is not going to become electrically unsafe because of one extra non-compliant wall switch, considering all the other existing switches are equally non-compliant. It is good to know they will all become compliant with the regulations again once the CU is upgraded.

Just exploring the options... For now I may even just connect the new light to be switched with the existing, since it will rarely (never?) be used by itself. Not ideal as that just means it will be often be on when it isn't actually needed.

 

[flameport]

Put a ceiling pull cord in for now. Change it to a wall switch after the new CU is installed.

 

[ban-all-sheds]

Sshhhh I agree that option is the 'real world' and most cost-efficient alternative and that time is only 6 months away. But I always try to ensure that any DIY work done by me is compliant, hence my original question.

Also, it's amazing how long 6 months can take these days.

It's a garage FGS - run the cable on the wall in some trunking until you are able to bury it.

 

[Cam Black]

Put a ceiling pull cord in for now. Change it to a wall switch after the new CU is installed.

That's not a bad idea and not one I had considered (I tend to only think of bathrooms with pull cords). If I make the cable long enough now to reach the wall switch position it will be a simple swap later.

Also, it's amazing how long 6 months can take these days.

Ha ha, fair point - but if the kitchen (and CU) isn't built and finished in September I will have a lot more to worry about than a breach of wiring regulations

It's a garage FGS - run the cable on the wall in some trunking until you are able to bury it.

True, but it's MY garage and I made a point originally of avoiding surface mount purely for the aesthetics.

I think the extra expense of protected cable/conduit is pointless for this simple project. I'll probably go with the pull cord idea and swap it out later when I know I can safely hammer nails into all the safe zones in my house

Anyway, thanks to all suggestions/ideas. Much appreciated for my first post here.

 

[ban-all-sheds]

True, but it's MY garage and I made a point originally of avoiding surface mount purely for the aesthetics.

Go for the aesthetic point of neatly done surface conduit (or pyro) and surface accessories throughout?