socket off lighting circuit

[stevie h]

Is there anything in the regs that says you cant run a socket off the lighting circuit ? my obvious answer is that it cant/shouldn't be done , but another spark i know said you can to run booster aerials in lofts etc , and i suppose he is right as the lighting circuit is protected by the 5a mcb so there is no chance of overloading the cable.

 

[RWJ]

Nope it's 2.5mm but that's from socket to I'm presuming light in bedroom. Then I'm presuming regs would of made them put in 1.5mm for the lighting circuit

Why would you need to change the cable or a smaller one that can carry less current?


OP was Steve H (now a guest?)
Then SteveHubbard reopens the thread with a similar question.

 

[BlueToBits]

So why is it compliant to protect a 2A socket with with a device greater than 2A, and not compliant to protect a 13A socket with a device less than 13A?

 

[Wiredspark]

The plug that goes into the socket is fitted with a 2a fuse which protects the flex to the appliance.
You are not protecting the socket. You are protecting the cable that runs to the socket. You can run a 4mm cable to a 13a FCU, the 4mm cable is capable of handling more than 13a so you could protect it with a 16a or 20 MCB/RCCB/RCBO etc. It would be pointless protecting a 13a socket (wired in a cable capable of more than 13a with considerations to cable run length, ambient temperatures and installation referance method) with a 6a MCB etc as some numpty will undoubtably plug in an appliance of greater current drawing potential causing (nusense) tripping.

 

[BlueToBits]

The plug that goes into the socket is fitted with a 2a fuse which protects the flex to the appliance.
You are not protecting the socket. You are protecting the cable that runs to the socket. You can run a 4mm cable to a 13a FCU, the 4mm cable is capable of handling more than 13a so you could protect it with a 16a or 20 MCB/RCCB/RCBO etc. It would be pointless protecting a 13a socket (wired in a cable capable of more than 13a with considerations to cable run length, ambient temperatures and installation referance method) with a 6a MCB etc as some numpty will undoubtably plug in an appliance of greater current drawing potential causing (nusense) tripping.

Unless you are refering to a clock point, none of the 2A plugs I have ever seen has a fuse in it. - in fact non of the round pin types do, and I would go as far as to say, only the 13A plug and the UK clock point are fitted with fuses.

There is no such thing as "Nuisance Trippng". A Device only trips because it has detected a fault or overcurrent where the circuit design limits have been exceeded.
It is not a nuisance, it a safey feature. If a 13A socket is designed to power a TV amp, or a bedside light then 6A protection is plenty. The regs allow you to have an unlimited number of spurred sockets from a 13A fused connection unit, The number of sockets served by a 32A ring is only limited by the area it serves. In both these examples the circuit arrangement is designed to suit the intended connected load. You can't blame the designer if someone along the line wants to do something different with the installation. There is nothing wrong with this if it is part of an appropriate circuit design.

 

[truckster]

You can get 5A plugs/sockets with a fuse and round pins or a non standard plug/socket with a T earth pin, which would make it unlikely anyone will plug a arc welder in, but the FCU is probably the way to go

 

[Adam W]

IMO this is why sockets for appliances should never be put on lighting circuits. Sure at the time it might be for just an aerial booster, clock radio, tv etc where it would be inconvenient to chase out the walls because the customer has already decorated or just 'doesn't want' any floorboards lifted, but jump down the line a couple of years to when the furniture has been rearranged, new householder moved in, requirements changed etc, and that extra socket is in a convenient place to plug the hairdrier or vacuum cleaner in (obviously having not been close enough to a socket on a final circuit to spur off), the socket gets changed to a 'normal' BS1363, and hey presto, "nuisance" tripping.

IMO a BS546 round pin plug should only be used on a lighting circuit when it is clearly for a light ONLY and is switched in the same way as the other lights, AND adjacent to a BS1363 so it is no more convenient to use an appliance run from the lighting circuit.