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 .

 

[telectrix]

you can take only 1 outlet as a spur from a ring final unless you fit a 13A FCU

 

[Dave OCD]

I'm sorry I think you need to word your question a bit better, or it might just be me.

 

[Resu]

I'm sorry I think you need to word your question a bit better, or it might just be me.

Not just you!

 

[telectrix]

i got confused when he didn't mention john wayne (spurs).

 

[Dave OCD]

Better to mention Spurs than Arsenal at the moment.

 

[telectrix]

Arse who?

 

[Pete999]

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 .

1 spur per socket on the RFC See Appendix 15 BS 7671

 

[ChrisElectrical88]

As many as you see to be sensible with a 4mm twin and earth spurring off? I could be wrong, I'm not going to the van at this time for the BYB.

 

[Octopus]

As many as you see to be sensible with a 4mm twin and earth spurring off? I could be wrong, I'm not going to the van at this time for the BYB.

Wrong!

 

[Pete999]

Wrong!

What he said ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ring final circuits and radials - - Yahoo Image Search Results - https://images.search.yahoo.com/yhs/search?p=ring+final+circuits+and+radials&fr=yhs-mozilla-102&hspart=mozilla&hsimp=yhs-102&imgurl=http%3A%2F%2Felectrical-engineering-portal.com%2Fwp-content%2Fuploads%2F2016%2F10%2Fconsumer-unit-ring-final-circuit-ver-2.png#id=2&iurl=http%3A%2F%2Fi69.photobucket.com%2Falbums%2Fi62%2FRFLighting%2FIMGP2837.jpg&action=click

 

[telectrix]

what he said about what he above said ^^^^^. although 4mm is capable of handling the current in itself, adding several outlets to the same point on the rfc could overload the 2.5mm rfc cable especially if the point was close to one end of the rfc.

 

[ChrisElectrical88]

Ignore me then. Thank you for correcting me fellas.

 

[HandySparks]

1 spur per socket on the RFC See Appendix 15 BS 7671

There's no limit on the number of spurs on a ring. But not more than one accessory is allowed on any unfused spur.

 

[Richard Burns]

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.
An unfused spur will only supply a single point of use.
In practice you would be looking at the ring loading and ensuring that there were not a concentration of current drawn at one point of the ring.

 

[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.

 

[HandySparks]

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.

OK, your choice.

It's a bit odd that the OSG adds a requirement that isn't present in the regs. My guess is that it's a hangover from the 15th edition and the writers of the OSG haven't noticed that the requirement has been removed from the regs.

 

[Pete999]

OK, your choice.

It's a bit odd that the OSG adds a requirement that isn't present in the regs. My guess is that it's a hangover from the 15th edition and the writers of the OSG haven't noticed that the requirement has been removed from the regs.

So are you saying that as an example 10 sockets in a RFC you can't have 10 sockets as unfused spurs?

 

[HandySparks]

So are you saying that as an example 10 sockets in a RFC you can't have 10 sockets as unfused spurs?

No. I'm saying you can have as many unfused spurs on a ring as you like, irrespective of the number of sockets on the ring. I believe that this complies with the current regs.

 

[Pete999]

No. I'm saying you can have as many unfused spurs on a ring as you like, irrespective of the number of sockets on the ring. I believe that this complies with the current regs.

Yes Handy I can see where you are coming from now, well you live and learn

 

[Deleted member 26818]

Appendix 15 shows spurs taken from accessories and also spurs taken direct from the ring.