Can you overload a lighting circuit

GeorgeCooke:

I always say putting a 13a socket on a lighting circuit is bad practice. I can't really understand why it is permitted.

Ditto

GeorgeCooke:

I always say putting a 13a socket on a lighting circuit is bad practice. I can't really understand why it is permitted.

Outside of domestics it's quite common to have lights on some kind of plug & socket arrangement (often blue 16A ones) - I'm thinking of the likes of major railway stations with the light fittings way up high above the platforms. Much easier and safer to be able unplug & unhook the entire fitting and bring it down to ground level to work on.


  - Andy.

AJJewsbury:

A 13 A socket is expected to be able to deliver 13 A.

Humm, what about a 13A socket on a 32A ring where it just so happened two other sockets were already used to supply 13A loads?

   - Andy.

I agree with David Stone; this is unlikely to happen. Diversity takes care of things. Whereas appliances that consume close to 13 A do exist. If you plug one of these into a 13 A socket, diversity does not come into it; the socket is expected to deliver.

Legh Richardson:

Unfortunately, one should never underestimate the natural stupidity of a client. If it can be overloaded then it will. Such an example would be the use of BS1363 13A sockets to feed table lamps and standard lamps which are then likely to be used by the clients or cleaners to run their vacuum cleaners.


Even head teachers will declare their observancy when told not to use the 13A socket connected into the lighting circuit for anything else than the table lamp positioned in a small alcove on a stairwell. Then to find when next on site a vacuum cleaner plugged in to the very socket then to be told that "as an electrical novice I see a socket and use it because it fits and is the nerest to the stairs".

I changed it for a BS546 5A socket..

This is why I am anti the idea of installing a 13 A socket on a circuit of lower fuse rating. What is wrong with plugging these lamps into a 13 A sockets on an orthodox ring circuit? 


If you want a "dedicated" circuit so that you can switch all the lamps on or off together, you may have a case for using 5 A sockets. However this makes things less flexible; you may later want to remove one or more of these lamps to use elsewhere, where the available sockets are 13 A. I'd be interested in other readers' ideas of how many sockets one could instal on such a dedicated circuit. Why not instal a dedicated ring circuit with 13 A sockets? It would need a stouter cable but this would not add much to the cost, which would be probably mainly labour.


One situation where BS546 sockets are still preferred is theatre lighting. Each lighting circuit is individually fused, so we don't want an extra fuse in a plug blowing and complicating matters. It is unlikely that one would want to plug a theatre spotlight into an ordinary 13 A socket.

AJJewsbury:

GeorgeCooke:

I always say putting a 13a socket on a lighting circuit is bad practice. I can't really understand why it is permitted.

Outside of domestics it's quite common to have lights on some kind of plug & socket arrangement (often blue 16A ones) - I'm thinking of the likes of major railway stations with the light fittings way up high above the platforms. Much easier and safer to be able unplug & unhook the entire fitting and bring it down to ground level to work on.


  - Andy.

This is a good idea, also widely used in commercial offices with suspended ceiling lighting. Perhaps this idea could be extended to "dedicated" lighting circuits, rather than the obsolescent BS546 5 A sockets.

Denis McMahon:

One situation where BS546 sockets are still preferred is theatre lighting. Each lighting circuit is individually fused, so we don't want an extra fuse in a plug blowing and complicating matters. It is unlikely that one would want to plug a theatre spotlight into an ordinary 13 A socket.

Don't you believe it. I've made up a 'special' plug lead combination to PAT the PAR cans, floods and spots, as well as the various extention leads for our amdram lighting set up.

Legh