Spur help

joe68 · Nov 5, 2024

Hi all I need to put a new double socket in utility room for a fridge freezer.
The nearest socket I have to the utility room is in the dinning room just opposite the same side wall.
I was planning to spur of that single plug socket, which has 2 wires in this socket.
Will I be a able spur another 2.5mm cable out into a new double socket into the utility room or will need to spur from the single socket into a switched fcu then new wall socket. At the moment I've got fridge/freezer on a 13amp extension lead don't know if extension lead is good enough for the appliance

I also wanted to put a light in garage
Only have a wall socket which has one cable going out from this into a fcu which operates the garage door.
Will I be able to run another 2.5mm cable from the same socket into another switched 3 amp fcu and come out with a 1mm cable into a ceiling rose light

SPECIAL LOCATION · Nov 5, 2024

Welcome to the forum...

To give accurate answers we need to know the current protective devices for the circuit, and if its a radial or ring composition..
As you cannot assume what the existing circuit arrangements are just by the number of cables in a socket..

e.g.
A socket with one cable may be the last point in a radial circuit...
Or it may also be a socket spurred off a ring final.

A socket with two cables may be part of a ring final...
Or it may also be a mid-way accessory part way along a radial circuit.

A socket with three cables in may be a branching point on a radial circuit, (one supply in, with two feeds out)...
Or it may also be a branching point for a spur off a ring final, (two ring supplies in, with one feed out).

Basically a bit of continuity testing on the dead circuit is needed to verify its composition and thus what is the best method to extend / amend the circuit.

poni · Nov 5, 2024

SPECIAL LOCATION said:
Welcome to the forum...

To give accurate answers we need to know the current protective devices for the circuit, and if its a radial or ring composition..
As you cannot assume what the existing circuit arrangements are just by the number of cables in a socket..

e.g.
A socket with one cable may be the last point in a radial circuit...
Or it may also be a socket spurred off a ring final.

A socket with two cables may be part of a ring final...
Or it may also be a mid-way accessory part way along a radial circuit.

A socket with three cables in may be a branching point on a radial circuit, (one supply in, with two feeds out)...
Or it may also be a branching point for a spur off a ring final, (two ring supplies in, with one feed out).

Basically a bit of continuity testing on the dead circuit is needed to verify its composition and thus what is the best method to extend / amend the circuit.

you are right about the more info needed
as for the number of cables at any one point, the only time it really matters is when its two single sockets on the same spur off a ring final circuit, then you cant add to it unless you make one a FCU,
I would always recommend to fit a twin socket to save any confusion in the future

Mike P · Nov 6, 2024

If it was me I would run a new radial circuit with no RCD just an MCB. nothing worse than a fault on the ring circuit taking the fridge freezer out, especially if you are away!

DPG · Nov 7, 2024

Mike P said:
If it was me I would run a new radial circuit with no RCD just an MCB. nothing worse than a fault on the ring circuit taking the fridge freezer out, especially if you are away!

How would you comply with regs re protection?

Mike P · Nov 7, 2024

DPG said:
How would you comply with regs re protection?

A bit difficult to say as I don’t know the house layout. Under the floor or conduit!
If it’s safety protection (RCD) etc, I think if you mark and label the circuit as non RCD it is acceptable. Unless I haven’t spotted a regs change.

Andy™ · Nov 7, 2024

Mike P said:
Unless I haven’t spotted a regs change.

you're well out of date. that got taken out a long time ago

SPECIAL LOCATION · Nov 7, 2024

Mike P said:
A bit difficult to say as I don’t know the house layout. Under the floor or conduit!
If it’s safety protection (RCD) etc, I think if you mark and label the circuit as non RCD it is acceptable. Unless I haven’t spotted a regs change.

A non RCD but labelled socket was last permitted in 17th edition.. 411.3.3 point (b).

However since 18th edition blue 2018, 411.3.3. allowed an exception for a non RCD outlet is if is is NOT a dwelling and you have done a risk assessment.

And since the brown book 2022 it had the wording amended further relating to the categories of persons using the sockets by their utilization capability: BA1 / BA2 / BA3 (ordinary, children, disabled).

Murdoch · Nov 7, 2024

Cut plug off fridge freezer and connect to MCB / SFCU dedicated circuit

DPG · Nov 7, 2024

Murdoch said:
Cut plug off fridge freezer and connect to MCB / SFCU dedicated circuit

But is the circuit wiring suitable to have no RCD protection??

Murdoch · Nov 7, 2024

DPG said:
But is the circuit wiring suitable to have no RCD protection??

No idea - that's for the OP to outline to us to help them

binky · Nov 7, 2024

OK, food for thought. Assuming this is being spurred off a 32A ring main, wire the spur in 4mm cable, which is of course suitable for 32A without fusing down, given suitable installation requirements like not running through 500mm insulation.

poni · Nov 8, 2024

binky said:
OK, food for thought. Assuming this is being spurred off a 32A ring main, wire the spur in 4mm cable, which is of course suitable for 32A without fusing down, given suitable installation requirements like not running through 500mm insulation.

can you not do the same with 2.5mm as long as it feeds only one single or one twin socket?

Mike P · Nov 8, 2024

Murdoch said:
Cut plug off fridge freezer and connect to MCB / SFCU dedicated circuit

So what’s the difference between this and a dedicated radial marked as non RCD? Apart fro cutting off the plug!

Andy™ · Nov 8, 2024

Mike P said:
So what’s the difference between this and a dedicated radial marked as non RCD? Apart fro cutting off the plug!

not easy to plug in an extension and take it outside etc

poni · Nov 8, 2024

Mike P said:
So what’s the difference between this and a dedicated radial marked as non RCD? Apart from cutting off the plug!

no socket so no RCD

SPECIAL LOCATION · Nov 8, 2024

Mike P said:
So what’s the difference between this and a dedicated radial marked as non RCD? Apart fro cutting off the plug!

If you have a read of 411.3.3 you will answer your own question.
But here's a clue.. 411.3.3 is titled "Additional rules for socket-outlets etc.."

Also have a read of my earlier post#8..
You are no longer permitted to label Non-RCD socket circuits within a domestic dwelling. (18th edition 2018)

A hard-wired appliance into a fused connection unit, does not involve socket outlets.

binky · Nov 9, 2024

poni said:
can you not do the same with 2.5mm as long as it feeds only one single or one twin socket?

Yes

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