FUSED SPURS ON EVERY SOCKET

[stillp]

I've just done some searching here on this subject.

Some here reckon a 20A switch is not listed in BGB as being suitable for connection to a RF circuit, possibly for the same reason as ebee states, although I don't have access to a copy of BS1363 so can't confirm.

If this is so, can anybody quote the regs?

It's just that some questions go round and round and it would be good if we could nail this one and then give folk a definitive answer.

BS1363 doesn't cover 20A switches. They're covered by BS EN 60669-1. I'll get hold of a copy and check.

 

[JohnW2]

Some here reckon a 20A switch is not listed in BGB as being suitable for connection to a RF circuit, possibly for the same reason as ebee states, although I don't have access to a copy of BS1363 so can't confirm. If this is so, can anybody quote the regs?

BS1363 doesn't cover 20A switches. They're covered by BS EN 60669-1. I'll get hold of a copy and check.

I think the reg which people are thinking of is 433.1.103 of the BGB, one of the few places (other than Appendix 15) where much is said about ring final circuits. In the context of where it appears in the reg, it is really a 'dispensation' to have an RFC wired in cable of 20A CCC protected by a 30/32A OPD, not a description of 'what is allowed in an RFC'. However, it does say that such a circuit is allowed to supply accessories to BS 1363 (and, by implication, nothing else).

Daft though it would seem to me, I therefore think that a pedantic/literal interpretation of the regs would be that if the circuit supplies anything other than 'an accessory to BS 1363', then one loses that dispensation and would have to wire the RFC in cable with at least 30/32A CCC.

However, every inch of common sense suggests to me that a 20A switch should be fine. I certainly have some in my house being used in that way, and I'm sure that many others have!

Kind Regards, John.

 

[stillp]

Hmm, interesting. I can't find anything in EN 60669-1 that is relevant to connection in a RFC. The test current for temperature rise of a 20A switch is 25 A.

 

[securespark]

Still - yeah, ebee was saying that 20A switches do not comply with 1363. What I was trying to discover is whether the terminals would carry 32A.

Guess the answer to the question is to use a 1363 FCU above and an unfused connection below.

A 32A DP switch is not 1363, so that's out, too.

Yes, I'm aware of the age old argument that it does not really matter about discrimination. However, it's better not to have two 13A 1362's in line as the one that pops may be the inaccessible one.

 

[JohnW2]

Hmm, interesting. I can't find anything in EN 60669-1 that is relevant to connection in a RFC.

That doesn't really surprise me. As I've just written, I think the (almost pedantic) issue is that a literal interpretation of 433.1.103 of BS 7671 is that one loses the 'dispensation' to use 20A cable in an RFC if anything other than an 'accessory to BS 1363' is connected to it. But, as I also said, to use that to argue against a 20A switch in the feed to one socket strikes me as being plain daft.

Kind Regards, John.

 

[JohnW2]

Still - yeah, ebee was saying that 20A switches do not comply with 1363. What I was trying to discover is whether the terminals would carry 32A.

In practical (rather than 'regulation') terms, I've never really understood the concept of the 'current carrying capacity' of terminals in the sense we are talking of here (similar to the situation in a JB). As far as I am concerned, all that really matters is the mechanical 'conductor accommodation capacity' of the terminal - in a 'ring' situation, the current flow is primarily between the conductors in contact, not through the material of the terminal (i.e. the terminals serve essentially to keep the conductors in contact).

I would add that 20A grid switches are often used (perfectly satisfactorily) to supply kitchen appliances in the way we're describing, and they are quite 'modest' terminals.

To 'unnecessarily' use an FCU (rather than a 20A switch) just to keep on the right side of the perceived regs (i.e.justy because the FCU has 'BS1363' written on it) would seem pretty daft to me.

Kind Regards, John.

 

[stillp]

I agree with John, the terminals don't have to carry the current in the RFC, the conductors of the cable do that.
If the RFC is fully loaded then the temperature of the conductors could be high enough to increase the temperature rise of the switch, which might be why the temperature rise test for a 20A switch is perforemd at 25A.

 

[ban-all-sheds]

thanks for all your comments guys
the wife has decided shes wants underfloor heating
in the bathroom which is next to the kitchen. can i spur off the double socket
in the kitchen to a new fused spur for the heating.

UFH is notifiable.

A spur in the bathroom and/or the UFH controls could well be notifiable.

UFH may not be a good load to put on a ring circuit.

You really need an electrician.


UFH won't really warm the room, it won't dry the floor, it'll just make the tiles warm to walk on in bare feet. Slippers or a wooden floor might be cheaper

 

[wassanator]

what i ment to say was if i replace the fused spur with a juction box and the spur off the double socket would this be ok

 

[RF Lighting]

I've just done some searching here on this subject.

Some here reckon a 20A switch is not listed in BGB as being suitable for connection to a RF circuit, possibly for the same reason as ebee states, although I don't have access to a copy of BS1363 so can't confirm.

If this is so, can anybody quote the regs?

It's just that some questions go round and round and it would be good if we could nail this one and then give folk a definitive answer.

I think it's more to do with 433.1.5 in BS7671, rather than BS1363 it's self.

"Accesories to BS 1363 may be supplied through a ring final circuit, with or without unfused spurs,......"


<edit> sorry I didn't see there was a page two on this thread

 

[JohnW2]

I think it's more to do with 433.1.5 in BS7671, rather than BS1363 it's self.
"Accesories to BS 1363 may be supplied through a ring final circuit, with or without unfused spurs,......" ... <edit> sorry I didn't see there was a page two on this thread

As you note, I said this way back ... but you really ought to invest in a BGB - it's 433.1.103 these days

Kind Regards, John.