Advice on a spur socket off the ring main

[Harry Bloomfield]

If anyone can think of any difference between having two single sockets and one double, I should be very interested.

Also, with all the nonsense talked about the load a double socket can handle, any reason why two singles is not, in fact, better.


Not to mention using 4mm² cable for the spur when any restrictions disappear.

One reason that comes to mind, is that you would be unlikely to plug 2x 3Kw fan heaters into one double socket - you might if one single socket were in one room and the second spur in the next room.

I doubt these days that my ring needs to support more than a couple of hundred watts, under normal circumstances and I have had no abnormal circumstances here in the last 50 years.

 

[EFLImpudence]

One reason that comes to mind, is that you would be unlikely to plug 2x 3Kw fan heaters into one double socket - you might if one single socket were in one room and the second spur in the next room.

Why would that matter?

 

[JohnW2]

If anyone can think of any difference between having two single sockets and one double, I should be very interested.

Only the fact that, as eric has implied, for those incapable of thinking, a 'single simple' instruction that they must not have an unfused spur feeding more than 'one thing' is perhaps most likely to be within their capabilities of understanding!

Also, with all the nonsense talked about the load a double socket can handle, any reason why two singles is not, in fact, better.

Indeed - although I suppose those those who insist that a double socket is only 'rated' at 20A might be happier with that than with 2 x "13A" sockets (given the minimum CCC requirement of cable in a ring final).

Not to mention using 4mm² cable for the spur when any restrictions disappear.

Quite - but only for those capable of thinking!

Kind Regards, John

 

[Harry Bloomfield]

Why would that matter?

The maximum load of a twin socket is 20amps. 2x 3Kw at 240v is 25amps.

 

[EFLImpudence]

So - two singles would be better.

I think you are arguing the wrong way round.

 

[Harry Bloomfield]

So - two singles would be better.

I think you are arguing the wrong way round.

I read your comment as why would it matter if there were two 3Kw loads on a twin socket.

I'm not certain of the precise rating of 2.5mm T&E, but from memory around 20 or 21amps. If there were a single on the ring, with a single spurred from that, then a second one spurred off that - the cable between ring and the first spur would be having to carry 25amps, assuming both spurs were loaded to 3Kw.

 

[dannyboi2003]

I have an old Home Electrics book of my Dad's that I used to read all the time when I was younger and fascinated by electrics. I distinctly recall it stating that you could take an unfused spur to 2 x single sockets or 1 x double socket, I've just dug it out and attached some pics. No regs are stated but thought some of you might find the history behind the varying 'can you spur from a spur' opinions interesting.

HE1

• dannyboi2003
• 11 Jul 2020

HE2

• dannyboi2003
• 11 Jul 2020

HE3

• dannyboi2003
• 11 Jul 2020

HE4

• dannyboi2003
• 11 Jul 2020

HE5

• dannyboi2003
• 11 Jul 2020

HE6

• dannyboi2003
• 11 Jul 2020

 

[Harry Bloomfield]

Yes, thanks Danny, I thought I was correct.

 

[EFLImpudence]

I read your comment as why would it matter if there were two 3Kw loads on a twin socket.

No, appendix 15 states one single or one double. Why is two singles not allowed as it is better?

I'm not certain of the precise rating of 2.5mm T&E, but from memory around 20 or 21amps. If there were a single on the ring, with a single spurred from that, then a second one spurred off that - the cable between ring and the first spur would be having to carry 25amps, assuming both spurs were loaded to 3Kw.

It is 27A method C - therefore...

 

[EFLImpudence]

...

 

[EFLImpudence]

Yes, thanks Danny, I thought I was correct.

Please explain.

 

[EFLImpudence]

Ah. I see now.

So why is it not allowed now?

 

[dannyboi2003]

I probably should have stated For anyone reading this in the future that taking a spur from a spur is not allowed under the current regs and far as I know it never actually was. That old book is a Hone owners guide and no regs are quoted anywhere in it.

 

[EFLImpudence]

that taking a spur from a spur is not allowed under the current regs and far as I know it never actually was. That old book is a Hone owners guide and no regs are quoted anywhere in it.

It is not Correct to say that as a blanket statement.

It depends on the design.

 

[JohnW2]

I probably should have stated For anyone reading this in the future that taking a spur from a spur is not allowed under the current regs ...

Indeed (silly thought that may be in the case of teo single sockets).

... and far as I know it never actually was.

Now that you have prodded my memory, I seem to recall that the regs did once allow what the books says - one double or two single sockets (which, as above, would probably be more sensible than 'current regs').

Kind Regards, John