2.5 mm extension to 4 mm ring?

[verticalwater]

Hi, Novice here!

I want to extend a ring main and add 3 double 13 amp sockets into an internal garage I've converted to a play room.

I've read all the do's and don'ts and have researched the cable size (2.5 mm).

I've bought the cable and all the accessories and was about to start the job when, taking off the socket I want to start my extension from, I find the cable is 4 mm.

Do I have to continue the extension in 4mm. or can I use the 2.5mm. I've bought?

Thanks.

 

[kme]

Are you CERTAIN its a ring; you can happily have a 4mm radial on 4mm........

If its a 4mm radial, best option would be to use 4mm

You could use 2.5, and reduce the 32A to a 20A; but make a note of what you`ve done at the CU, for future reference.

OR, you could use your 2.5, and make a ring from the 4mm; again you`d need to make a note of this......

Also, do be aware that you need to be able to carry out the necessary tests on the circuit; both before & after you`ve done the works; (preferably provining a minor works certificate, too.)

KME

 

[Apache]

Is your plan to join the three sockets inside the ring or to have them as a spur off the ring?

 

[Andy™]

Hi, Novice here!I want to extend a ring main and add 3 double 13 amp sockets into an internal garage I've converted to a play room.

I've read all the do's and don'ts and have researched the cable size (2.5 mm).

I've bought the cable and all the accessories and was about to start the job when, taking off the socket I want to start my extension from, I find the cable is 4 mm.

Do I have to continue the extension in 4mm. or can I use the 2.5mm. I've bought?

Thanks.

assuming it really is a ring and not a radial, then 2.5 could be used providing its capacity is 20A or greater after derating. which may be why its wired in 4mm now

 

[verticalwater]

Not spurs, but to extend the ring.

The house is 8 years old, one of the generic "Cardboard Box" type.

 

[Andy™]

8 years old makes no difference to whether its a ring or radial. you will need to confirm either way before you can go any further

 

[Larnacaman]

Just a thought here! ....Is that 4mm Al/Cu plated stuff still in use in the UK?? Was just thinking, maybe this house has been wired with the stuff instead of the normal copper wiring!!! Horrible stuff.....!!!

 

[PC Electrics]

Just a thought here! ....Is that 4mm Al/Cu plated stuff still in use in the UK?? Was just thinking, maybe this house has been wired with the stuff instead of the normal copper wiring!!! Horrible stuff.....!!!

I'm tempted to 'groan' at you for that!

I think that post is more likely to muddy the waters and confuse a novice rather than help.

OP

Are you sure the circuit is a ring final?

Are you sure it's 4mm? (I was going to suggest it might be imperial cable, but somehow I doubt it if the house is only 8 years old)

Is it on a 32A MCB? Might be a 32A/4mm radial

 

[Larnacaman]

What!!!!! It's a dammed sight more relevant than suggesting it maybe ''Imperial '' cable that hasn't been seen in the UK for well over 20 odd years.

Soooo, where's the confusion, if that Al cable is still in use??

 

[kerching]

Copperclad [Al/Cu] was only used for a few years around the late 70s [i think]. introduced because of a copper shortage, also it was s4!te. worse still was the MICC version...AlCuMIC. absolute pants!!! I still have a few of the pots and seals kicking about somewhere; no idea why I kept them really, probably nostalgia