Spuring off a Switched Spur

[claret73]

This may be quite hypothetical for now, but can I take a feed out of the incoming side of an FCU (If it was either a radial or Ring Final) to feed a 2nd FCU which would provide a load out to a boiler?

Spoke to the plumber asking if he has power next to the boiler and mentioned the spur. If it's off the Ring originally then I assume no difference to spurring off a Socket outlet?...Good or Bad Practice? Not looked at it yet, just trying to pre-empt anything.
Thanks!

 

[claret73]

Didn't mean to start a war Lads! I haven't looked at it yet, but Jud that's what I was thinking initially. If the spur is connected to a ring, then taking off the load is only a spur off that like a socket. I guess I'd need to test to see that there aren't already Spurs in existence (which might be highly unlikely...)

GrimySparks, that sounds a useful option. Hopefully I've got this right & maybe is unnecessary?? I could put a new FCU next to the original, Split the legs and bridge between. Both now wired into the ring. Keep the new at 13A & take the load 1x 2.5mm to the 2nd FCU. Then Load out of that to the Boiler. If the original is next to the Boiler in proximity then could just take my flex out of the first FCU & fuse down, marking the FCU as the Boiler.

 

[DarrenA]

You can spur off a FCU as long as its on the ring, or radial circuit.

You can't spur off a spur (even if its 2 FCU's protecting 2 cicuits of, say 3A each) - which IMHO is silly as you can spur off a socket to a double socket and plug in 2 3KW heaters!

And even worse, the regs allow you to use unfused socket doublers (the small cube things) and essentially double the draw! So this could potentially be 52A/12KW (in practice < 32A or the ring MCB would trip but still more than 2.5mm is allowed) from a double socket off a spur and be compliant but 2 FCUs carrying 26A max is for some reason not ok?

 

[DarrenA]

Oops newb here! Hadn't realised I was replying to a 12+ year old thread.

Are threads normally locked after a while so this can't happen?

 

[littlespark]

Oops newb here! Hadn't realised I was replying to a 12+ year old thread.

Are threads normally locked after a while so this can't happen?

Obviously not. Lol


Those cube adapters are always fused… they have to be. If not, then you’re buying unsafe non compliant products.

 

[DarrenA]

Obviously not. Lol


Those cube adapters are always fused… they have to be. If not, then you’re buying unsafe non compliant products.

That's not the case, some are unfused and the regs say only ones with 3 or more sockets need to be fused (unless the regs have changed?)

Here just a couple of examples:

Adaptor

BS1363Multiple adaptor for plug socketsTurn a single socket into twoCompact cube shapeEasy grip design

www.toolstation.com

Masterplug 2-Way Double Socket Unfused Mains Adaptor Plug 13A - White | Wickes.co.uk

Masterplug 2-Way Double Socket Unfused Mains Adaptor Plug 13A - White

www.wickes.co.uk

 

[DarrenA]

That's not the case, some are unfused and the regs say only ones with 3 or more sockets need to be fused (unless the regs have changed?)

Here just a couple of examples:

Adaptor

BS1363Multiple adaptor for plug socketsTurn a single socket into twoCompact cube shapeEasy grip design

www.toolstation.com

Masterplug 2-Way Double Socket Unfused Mains Adaptor Plug 13A - White | Wickes.co.uk

Masterplug 2-Way Double Socket Unfused Mains Adaptor Plug 13A - White

www.wickes.co.uk

So there's nothing stopping the average Joe plugging 2 of these into a dbl socket that is connected to a 2.5mm 27A rated unfused spur and trying to draw up to 52A, and if unlucky enough to just draw 32A it won't trip the ring MCB but will overload the spur cable - and this is fully compliant. But you can't spur off 2 x 13A FCUs together which is max 26A and within the spur cables spec. Don't make a lot of sense.