Electrical socket from light switch for cctv.

[John Rumm]

It would only be fair, he had seen the way electricians wire aerials ;-)

[Bill Wright]

The best way to use coax for mains is to use the inner for line and the outer for neutral. Don't bother about an earth. No-one bothers connecting the earth these days. It's just a hang-over from the early days of radio when a good earth was needed for reception. Note that when you power your electric fire through coax you actually save on your electricity bill because the coax gets very hot and helps warm the room. There is no cost for this because it's the same electricity as is going through the fire, so you get the benefit of it twice. If the small of burning plastic bothers you just push the coax under the rug.

Bill

[Bill Wright]

Don't get me started.

[charles]

[Snip]

Bill's not wrong. When a student and working with SSEB, I came across a small area in Edinburgh which was wired with "concentric" mains cable.

[Bill Wright]

Well there you are then. What's good enough for Auld Reekie is good enough for me. What was the csa of the inner, by the way? A tad more than 1mm2 I would guess?

Of course nowadays they use coax with two inners for mains supplies...

Bill

[harry]

There was indeed coax for mains. The core was live. Of the outer conductor, half the strands were individually insulated, which were neutrals and the the other were not, which were the earth. Haven't seen any for forty years. It was supposed to be safer as the live conductor was inside the others.

[The Natural Philosopher]

You sure? when I laid mine it just had an outer and an inner.

[John Rumm]

Its called "split concentric"...

Still in common use, you can see it here:

It was supposed to be safer as the live conductor was inside the > others.

I suspect its real benefit is its much harder to stick nails through and steal electricity.

[meow2222]

I didn't think that was regs compliant. Plugging normal loads in would result in circuit overload.

NT

[A.Lee]

Considering most lighting circuits are in 1.5mm T+E, the cable can run

13 amps continuous if it is on a plasterboard ceiling, covered by thermal insulation. A change from 6A to 10A CB would suffice if the 6A was likely to be exceeded, and still gives a big margin for safety of the cable.

Apart from some heaters and other large current eaters, lighting circuits would be quite capable of carrying a number of socket outlets if they were marked for low wattage appliances. It is common for extractor fans and TV boosters/Sky boxes to run from the lighting circuit in an attic.

[Dave Liquorice]

The lighting fuse/MCB would then operate...

Donno what the regs say but I can't see what is wrong with a 13A socket connected to the lighting circuit via a FCU and 3A (or smaller) fuse. Everything suitably labled as well.

I think there still needs to be clarification from the OP of what he means By "Is it acceptable in the uk to put a socket for a cctv camera off of a light switch?"

Is he looking to derive a power feed from the back of a light switch direct to a socket or use a light switch as a switch to a remote socket fed from a ring main or lighting power?

[meow2222]

'apart from.'

Many electrical items are capable of more than the regs permit. Bell wire is a classic example.

NT

[John Rumm]

in circuit overload.

I am not aware of any specific regulation that says you can't use a 13A socket on a circuit with a lower rating.

The main concern would be that a high load connected to it would cause tripping of the circuit, and that in turn may pose a risk due to loss of lighting. Hence it is required that the designer make sensible decisions. So rigging an extra socket on your landing that is fed from the lighting circuit would not be sensible - since someone is very likely to plug a vacuum cleaner into it etc. However one in the loft space intended to feed an aerial amp really poses no risk. Likewise, socket designed for powering table lamps etc would be fine on a lighting circuit - although in that circumstance using a physically incompatible socket would make sense since it will be in proximity to general purpose power sockets.

Cables on lighting circuits are usually fairly generously oversized, and the cable rating is significantly in excess of the circuit breaker. So you can't create a situation where you can overload the cable.

(a similar situation exists with a typical cooker on a 6mm^2 radial with a 32A MCB)

[Dave Plowman (News)]

You could probably get fencing wire to 'work' too. ;-)

[Lieutenant Scott]

My light switches have a neutral. The mains is under the floor, comes up through the lightswitch, to the lighting in the ceiling.

Just as well, as I fitted automatic lightswitch (with a PIR) which need power.

Mind you one of my light switches for some reason doesn't have a neutral present. But earth suffices as a neutral.

[Lieutenant Scott]

[Dave Plowman (News)]

More likely scenario is someone plugs in a vacuum cleaner or whatever into a lighting circuit on a dimmer, and fooks the dimmer.

[critcher]

critcher said................... I remember my mum plugging her electric iron into the light socket, but she couldn't see what she was ironing at night.

[critcher]

hang on I remember now, she had a socket with a dual output on it.

[Lieutenant Scott]

Didn't she have a

?