spurs

[steve 111]

what is maximum amount of spur sockets taken from a main , the main amperage can be changed easily the wiring is 2.5 and a ring main is not possible without a lot of work as this is a large old house which has been wired this way , there will only be one large consumer a water heater .

 

[HandySparks]

If you have a ring final circuit then the recommendation is that the number of unfused spurs does not exceed the number of point on the ring. e.g. with ten sockets of the ring a maximum of 10 unfused spurs is recommended. The number of fused spurs is unlimited.

I'm clearly missing something here, as both you and Pete999 have mentioned this. I can't find anything in the current edition of the regs about a limit on number of spurs, although maybe I've read it in a previous edition.

 

[Pete999]

I'm clearly missing something here, as both you and Pete999 have mentioned this. I can't find anything in the current edition of the regs about a limit on number of spurs, although maybe I've read it in a previous edition.

Have you looked at Appendix 15 in the BYB

 

[Richard Burns]

I'm clearly missing something here, as both you and Pete999 have mentioned this. I can't find anything in the current edition of the regs about a limit on number of spurs, although maybe I've read it in a previous edition.

As I say it is a recommendation not a regulation.
It is mentioned in the OSG under standard circuits.

 

[SparkyChick]

Having re-read the OP, I'm not sure we're talking about a ring....

"what is maximum amount of spur sockets taken from a main , the main amperage can be changed easily the wiring is 2.5 and a ring main is not possible without a lot of work as this is a large old house which has been wired this way"

I think he's talking radial.

 

[HandySparks]

Have you looked at Appendix 15 in the BYB

Yes. Can you tell me where in Appendix 15 this is referred to?

 

[HandySparks]

As I say it is a recommendation not a regulation.
It is mentioned in the OSG under standard circuits.

Thanks. Can't find my OSG at present.

I have found it in the 15th edition, Appendix 5, paragraph heading "Spurs".

 

[HandySparks]

Thanks. Can't find my OSG at present.

I have found it in the 15th edition, Appendix 5, paragraph heading "Spurs".

Just found my OSG. Yes, 7.2.2, still retains this clause. Looks like it's out of step with the current regs.

 

[Richard Burns]

Having re-read the OP, I'm not sure we're talking about a ring....

"what is maximum amount of spur sockets taken from a main , the main amperage can be changed easily the wiring is 2.5 and a ring main is not possible without a lot of work as this is a large old house which has been wired this way"

I think he's talking radial.

Interesting you could well be right. With main I assumed ring main.
If it is a radial then spurs are not possible, only branches, which are also unlimited though again recommended to be minimised (I think).
A 20A radial could be run all over the place without overloading a 2.5/1.5 mm² cable, though a large house circuit may experience nuisance tripping.

 

[Richard Burns]

Thanks. Can't find my OSG at present.

I have found it in the 15th edition, Appendix 5, paragraph heading "Spurs".

I did not know that!

 

[Pete999]

Yes. Can you tell me where in Appendix 15 this is referred to?

Between App 14 and App 16 Sorry couldn't resist Page 453 in my copy

 

[Pete999]

Yes. Can you tell me where in Appendix 15 this is referred to?

Sorry mate I misread your post, off hand no I can't but it's not a very big appendix 3 or 4 pages most of the appendix is diagrams

 

[Pete999]

Yes. Can you tell me where in Appendix 15 this is referred to?

Or On Site Guide: 7.2.2

 

[Pete999]

Just found my OSG. Yes, 7.2.2, still retains this clause. Looks like it's out of step with the current regs.

Why?

 

[HandySparks]

Sorry mate I misread your post, off hand no I can't but it's not a very big appendix 3 or 4 pages most of the appendix is diagrams

Appendix 15 is two pages. One on rings and one on radials. There's no reference to number of spurs off a ring.

 

[Pete999]

Appendix 15 is two pages. One on rings and one on radials. There's no reference to number of spurs off a ring.

You are correct it doesn't, but the OSG is what it is a guide BS7671 is a regulation and imo if someone is in doubt about something, the OSG is where to go and look.