Electrical socket from light switch for cctv.

[critcher]

yes, that was in my second post.

[Lieutenant Scott]

How did you accidentally remember it being dark? Maybe the iron used more than

5 amps.

[ARW]

window and using strip connector to extend an aerial cable:-)

[ARW]

I don't know of a reg that forbids it provided that the outlet is labelled for a specific appliance.

And if someone did plug a 3kW heater in then the fuse or MCB will trip and nothing bad happens.

[meow2222]

That's about what they used when Victoria was still alive.

NT

[Adam Funk]

That's how the electric fence was discovered, right?

[<me9]

But an FCU with 3a fuse may be required (or at least desirable) for discrimination, to protect from loss of lighting due to plugging in an appliance of excessive rating. This is assuming that a 13a socket outlet is used to connect teh camera supply.

[John Rumm]

Yes its a valid argument, although its debatable if you will actually get much discrimination with the arrangement in that order. (i.e. MCB upline of a fuse). Also if fitting a socket to a lighting circuit it will normally be for a specific purpose rather than a general socket, so the chances of accidental overload should be small.

The main argument for using a FCU etc would be for connecting a bit of fixed equipment that specifies it must be protected at 3A.

[bert]

In message , Bill Wright writes

Err no. If you're getting heat out he cable it's because it has resistance which reduces the total current through the cable/fire combination. Any heat gain in the cable has an equal reduction in the fire.

[bert]

I had reason to look up the wring regs regarding using a surplus earth as a neutral in my room thermostat. Definite no-no. Also wrapping the visible end with blue tape also a no-no.

[polygonum]

Is that better?

[John Williamson]

Err...

You're right about the resistance in the cable causing it to heat up. But... You save money per hour of running time due to the reduced power drawn, but you also get less total heat per hour for the same reason. The cost per kilowatt hour of heat is the same, ignoring losses outside the room.

[Owain]

Unless you're on a two-tier tariff, or one with a standing charge, in which case the average cost per kilowatt-hour will fall the more you use.

Owain

[John Rumm]

I think you may have missed Bill's tongue being firmly in his cheek there!

[John Rumm]

Using an earth as a neutral is a way to ensure an instant RCD trip on a recent installation.

[bert]

Yes I agree In fact I had overlooked the impact of higher total resistance resulting in less power, but the original poster of the comment implied or stated you were getting extra heat for nothing, which is wrong.

[bert]

Irony and T-I-C don't do well on t'internet

[bert]

If you want to use it as a neutral then you disconnect both ends from earth.

[John Rumm]

If you read much of Bill's output you would realise they are both alive and well ;-)

[John Rumm]

I suspect that scotty (being a class A plonker) was suggesting that one can use it directly while still connected to earth at the far end. (still its safe for him, because mains shocks are not dangerous he tells us!)