I've read somewhere that there are limits on the number of spurs allowed on socket radials, but does this apply to lighting circuits?
Or can I have a central spine with several radials going off for the lights and/or switches in various rooms, more than 50% on spurs?
Lighting is normally wired as a radial circuit using 1mm or 1.5mm T&E
that is protected buy a 6A MCB - therefore the word spur is not
applicable to such a circuit.
So basically you can wire it up however you want (voltagedrop and PSC apply)
True. So with a 2.5mm ring you are allowed one unfused spur for every
point on the ring.
Note that a 4mm 32A radial has the same rules ie a 2.5mm unfused spur
from the 4mm circuit is generally limited to the same regs.
Now a 20A 2.5mm radial only uses 2.5mm T&E and therefore cannot have an
I know many an electrician that is totally against the use of unfused
spurs - however used correctly there is nothing wrong with them
(and anyone who did a newbuild or a rewire with lot's of unfused spurs
is probably mad)
What's wrong with unfused spurs on a radial socket circuit?
I would think fused spurs are annoying because the houseuser might not find the fuse- you expect a fuse at the consumer unit or in the appliance's plug.
n Monday, January 15, 2018 at 7:10:55 PM UTC, ARW wrote:
On a 20A radial, there is (generally) no such thing as a spur, since
the circuit can branch in any topology you like.
With a 32A radial with 4.0mm^2 backbone, then you are back to the same
rules as for a 32A protected ring.
 I suppose you could take an unfused spur in 1.5mm^2 T&E, but only if
its installed to method C
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