Cannot have a Spur off a spur but can use an extension lead?

[Brian Matthews]

Probably a stupid question but why is it that you cannot (I think) run a spur off a spur but can connect an extension lead with loads of sockets on it? My son needs about six sockets in a new kitchen where there is only one double socket at present. How can it be done? As a matter of interest, we are trying to get an electrician in the Whitehaven, Cumbria area with no success. Are they all too busy?

Thanks

Brian

 

[telectrix]

the reason you can do it is that the extension lead is fused at 13A and so even if you overload the exrension, the 13A fuse will blow and the fixed wiring will not be subjected to overload.

 

[Brian Matthews]

the reason you can do it is that the extension lead is fused at 13A and so even if you overload the exrension, the 13A fuse will blow and the fixed wiring will not be subjected to overload.

Thanks for that, so if a fused double socket could be found (if such a thing exists), would that be OK?

 

[Baddegg]

Thanks for that, so if a fused double socket could be found (if such a thing exists), would that be OK?

Or if I’m understanding correctly you could spur of off the double into a 13a fused spur and put what you like after that point, although probably not a great design in a kitchen if I’m honest….thinking tumble dryer iron kettle toaster…..you’ll soon get bored of that fuse popping….plenty of good sparks on here from your way I’m sure one of em will be happy to have a look ?

 

[Brian Matthews]

the reason you can do it is that the extension lead is fused at 13A and so even if you overload the exrension, the 13A fuse will blow and the fixed wiring will not be subjected to overload.

Just found these:

MK 13 Amp Double Pole Fused Triple Switched Socket​

Isn't this just like have a 'built in' extension lead?

 

[timhoward]

It depends if you want the hassle of calculating loads…for example a kettle, toaster and microwave exceed 13 amps if all run together.

 

[Brian Matthews]

It depends if you want the hassle of calculating loads…for example a kettle, toaster and microwave exceed 13 amps if all run together.

Well it's not hard to calculate loads, just convert all the powers to current and add them up. So, theoretically I could use one as long as all loads come to less (ideally) than 13A.

 

[pc1966]

Is the double socket currently in the kitchen already a spur? If it is part of a ring final circuit (RFC) then that ring could be looped around another couple of sockets.

Kitchens normally need proper provision of power (professionally, not necessarily by Peter Piper...) as they are often the highest concentration of high power appliances, such as cookers, dishwashers, kettles, washing machines, etc. All heat stuff and that is power-hungry. So really it is something you should consider having done by a spark.

As already mentioned, if you have an over current protective device such as a 13A fuse then whatever you add beyond that can't overload the supply cable, as if it is already a spur it is probably on 2.5mm cable and that is often only able to carry 20A (or occasionally less, if in a hot region or thermally well-insulated) so by extending it carelessly you risk it overheating as (probably) the RFC feeding it is on a 32A breaker due to the provision of two cables to each point.

 

[pc1966]

Just found these:

MK 13 Amp Double Pole Fused Triple Switched Socket​

Isn't this just like have a 'built in' extension lead?

Essentially, yes. They include the 13A fuse as there is a high probability of it being used as a spur.

What is "legitimate" is to have a 13A FCU feeding a set of sockets, essentially a hard-wired extension lead, but as already said, it is bad practice in most cases as the end users typically will NOT calculate the usage and so will blow the fuse regularly and be tempted to do something stupid like stick a bolt in its place. Really if it is more than the odd "I need a 3rd socket" for a bedroom or similar then it should be done properly, so extending the ring, wiring in a new circuit, or in some cases when the house wiring is already screwed up by past DIY/builders monkeying with things by dropping the supply OCPD to 20A so all 2.5m wire is fairly safe.

 

[Brian Matthews]

Is the double socket currently in the kitchen already a spur? If it is part of a ring final circuit (RFC) then that ring could be looped around another couple of sockets.

Kitchens normally need proper provision of power (professionally, not necessarily by Peter Piper...) as they are often the highest concentration of high power appliances, such as cookers, dishwashers, kettles, washing machines, etc. All heat stuff and that is power-hungry. So really it is something you should consider having done by a spark.

As already mentioned, if you have an over current protective device such as a 13A fuse then whatever you add beyond that can't overload the supply cable, as if it is already a spur it is probably on 2.5mm cable and that is often only able to carry 20A (or occasionally less, if in a hot region or thermally well-insulated) so by extending it carelessly you risk it overheating as (probably) the RFC feeding it is on a 32A breaker due to the provision of two cables to each point.

Thanks for the informative reply. I would love to employ a sparky, if I can find one. Two came, looked at it and suggested a new consumer unit (which we do need) and various other suggestions. Not heard from them since. I don't smell so do not understand why we cannot get one. Need someone to fit a new, larger consumer unit and extra sockets in various places. I can do some thing myself but consumer units are a no no. I would prefer the other wiring to be done as we would then get a certificate (I hope).