LV Lighting supply dilemma

[andrewpreece]

I have some LV halogen lamps I want to put in my airing cupboard, but they are supplied with a plug-in type transformer. The most convenient supply is a lighting radial, but I can't fit a socket of any sort to a lighting circuit, am I right in saying? Is there any way I can supply a plug-in transformer from a lighting circuit?

Next option, more difficult, is to supply it from the mains. I have nearby a radial from the consumer unit which runs the immersion heater: also split off this radial ( at an unknown point, probably under the floorboards ) are a 300W shower and the central heating supply ( pump, timer etc ).

Am I allowed to add another spur from this radial to a 13A socket, which I can plug the 2 x 20W lights into, via their transformer? Also, whilst this is technically a fixed electric appliance, I can't see how I can work a fused connection unit ( say 3A ) into things, as the transformer must plug directy into a socket. My thoughts are that I don't need a fused socket or whatever, because these things are intended to be plugged into whatever

13A socket is handy.

Any advice appreciated,

Andy.

[Sparks]

It would probably be a lot less hassle to just buy a new transformer for the lights!

(You can always sell the other ones on eBay too!)

60w dimmable one from screwfix is £5.99

[Christian McArdle]

I assume you mean the transformer is a wall wart type with integral plug?

I would use an unswitched 13A socket indelibly marked "lighting only" fed from an adjacent 3A FCU on the lighting circuit. It probably isn't quite compliant with regs, but it'll be reasonably safe.

The main safety issue is that when the next occupier plugs the vacuum cleaner or a fan heater into it and the lighting MCB blows before the fuse, it will cause the lights to go out and granny might fall down the stairs in the dark.

Basically, to do it properly, you need to find a proper socket circuit somewhere to tap into.

Christian.

[stefek.zaba]

(Not our granny: she doesn't do stairs at all any more...)

Indeed, to make it less likely to pop the MCB under an inappropriate load, you could do a lot worse than fit a 1A fuse into the FCU. The 1A will indefinitely feed 300W or more of halogen lighting (no, fuses do not blow at 1.0001 times their nominal rating ;-) but if some mumpty plugs in the vac, hair dryer, or fan-heater into the clearly-marked Lighting Only socket there's a sporting chance that the 1A cartridge fuse will pop before the 6A lighting MCB. Only a sporting chance, mind, given that cart-fuses and MCBs have rather different time-to-blow-on-overload characteristics, and that the MCB will be supplying other lights too - so might be feeding 5A to other loads on the same circuit which Mumpty just plugged an electric chainsaw into... but a sporting chance nonetheless.

HTH - Stefek

[andrewpreece]

nonetheless.

Thanks all - I didn't mention that the socket would be in a space above the top of the airing cupboard ( lined with wooden wainscotting ) so won't be visible, or accessible easily, so maybe the 13A socket with a Dyno'd "Lighting Only" label plus a 1A FCU is the way to go. Probably non-regulation but I bet there're very few houses in the country that are totally regs-compliant. The main thing is that it should be safe and reliable.

The idea of using a different transformer is good, but then these lights and transformer were bought at IKEA for very little money and it seems a shame to buy more expensive stuff, also the present TFMR is moulded to the LV cable.

cheers,

Andy.

[Christian McArdle]

OTOH, it needs to have some accessibility to change the fuse. Also, a label near the lighting indicating the position of the non-obvious FCU may be in order.

Christian.

[Dave Plowman]

I'd also make a strap up out of aluminium that goes over the wall wart and fix it to the wall etc - something to make sure anyone who does try and unplug it to use the socket for something else does so absolutely deliberately. Make sure you don't block any ventilation slots, though.

[Chippy]

I suggest that you fit a 5Amp lighting socket to the lighting circuit, then make up a short cable with a 5Amp lighting plug on one end and an extension lead type 13Amp socket on the other.

To be extra safe I would attach the wall wart to the 13A socket permanently - some impact adhesive would do the job.

You now effectively have a transformer with a lighting circuit plug, and a socket which will only take lighting plugs.

True, but I think that the above is a good compromise.