2 gang FCU?

[sparkwright]

If they're feeding heavy stuff, they're best on a radial of their own. Good circuit design should prevent such a heavy load at any one point in an RF circuit.

If the spurs are not feeding powr-hungry equipment, then put a fused spur in limiting the load on the spur to a total of 13A.

that's what i'm thinking.

 

[GaryMo]

Is there anything in BS1363 that relates to total loading of a double socket?
I've not got the standard to hand.

BS 1363 requires a double socket to pass temperature rise tests when carrying 20A.

So that wouldn't apply to two single FCU's (or two single sockets) then as each would only be carrying 13A. The limiting factor being the supplying cable in that instance.

 

[GaryMo]

If they're feeding heavy stuff, they're best on a radial of their own. Good circuit design should prevent such a heavy load at any one point in an RF circuit.

If the spurs are not feeding powr-hungry equipment, then put a fused spur in limiting the load on the spur to a total of 13A.

that's what i'm thinking.

I agree with it you both good circuit design grounds but you wouldn't be in breech of BS7671:2008 by supplying two FCU's off a ring final which was always my point.

 

[sparkwright]

yes i totally take your point.

i think we've reached a compromise

but is it wrong to have a spur on a spur even in this case?
could anyone blindly change one fcu for a single or a double socket?

 

[GaryMo]

yes i totally take your point.

i think we've reached a compromise

but is it wrong to have a spur on a spur even in this case?
could anyone blindly change one fcu for a single or a double socket?

Yes, compromise being we agree I'm right (joke)

Wrong as in a non compliance? Do we know what the spurs are going to be supplying? It may have been mentioned but I don't recall it.

However, if one FCU was changed for a single socket then that wouldn't be a problem. If it was changed for a double socket then that would be a problem but then again it wouldn't happen as the electrician would be installing to BS7671:2008

 

[ccam108]

Would a departure from the regs not be allowed in this case as the fuses are 3A and 5A making a total of only 8A, running it as a spur from a spur?

Assuming of course that the loads are fairly permanent and not likely to be swapped for, say, two 3kW fan heaters.

Just while I'm thinking, would this be classed as one or two spurs, as it is one wiring accessory, no different from a double socket for instance?

Obviously I wouldn't condone a departure from regulations unless it is 100% safe and sensible etc.

Colin C

 

[GaryMo]

Would a departure from the regs not be allowed in this case as the fuses are 3A and 5A making a total of only 8A, running it as a spur from a spur?

Colin, which regulation would it be contravening if you're suggesting a departure?
I assume you have a specific regulation in mind?

 

[JohnnyG]

The only regulation I've seen is 4.2.2 (OSG & EGBR) which states that a non fused spur (which essentially it would be) can feed only one single/double/multiple socket outlet or one permanently connected item.
It's an odd one in this case as the max load will be fused at 8a but a multiple socket could have far more going on.

 

[GaryMo]

They're not regulations.

Have a look in BS7671:2008 and see if you can find any.

 

[ccam108]

I don't own a copy of BS7671:2008 so I couldn't give a regulation number. I'm just going on the multitude of posts on this issue in this forum which seemed to suggest that it was a hangable offence to spur off a spur.

Just looked at my OSG though and it says in 7.2.2 "A non-fused spur feeds only one twin or multiple socket-outlet or one permanently connected item of electrical equipment." No mention of "must" in that sentence, so would it be wise to then say that there is no problem with this arrangement due to the accessibility (airing cupboard) and fuse rating (8A combined)?

Colin C