Extending Ring

[Pfeet2]

Hi,

Newbie here and DIY homeowner looking for advice. I found a spur in our house with 5 double sockets on. Ideally I would like to keep the sockets, so am thinking about incorporating it into the ring by bringing the cable back from the end of the spur in to the next socket on the ring.

It would be under 100m2 but unsure how long the length of cable would be of the extended ring. I would need to bring it back by running it next to the outgoing cable. How could I go about working out the total length of the ring?

If there is a better way of keeping the sockets or anything else you think I haven't considered please let me know.

Thanks

P

 

[SparkyChick]

Is the spur fused or is it directly connected to the ring?

If it's fused and you're not blowing the fuse due to overload... leave as is. If it's not fused install a fuse before the first socket and see how it pans out. If you go 6 months without blowing the fuse I'd leave it at that.

Before we alter ring final circuits we first make sure they are correctly installed and free from faults. If you don't have the test equipment to do that, you could be making a bad situation worse by extending the ring to include those sockets. Installing a fuse before the first socket won't make anything worse than it already is, it will add protection to the spur and prevent you from overloading the cable.

If you're not comfortable doing any of that, get a recommendation from family/friends for a local spark and have them do it.... don't be pressured into anything more. That is the simplest method of making it compliant and perhaps is all you need to do.

 

[pc1966]

Well having several spurred off a ring is very bad as the main breaker is 32A but usually cable is 2.5mm which is 20-25A or so rated (but fine when ring-connected and current is shared). If you have more than one socket then it should be fed from a fused supply (typically 13A FCU)

Assuming you are looking at 2.5mm and taking the higher supply earth impedance (TN-S at 0.8 ohm) then the length limit would be 96m.

What you should do if making it part of the ring is to verify that all 3 conductors are forming a ring (i.e. no break somewhere) and that the resistances make sense. So the L and N rings should be more or less the same, and the E ring about 1.67 times higher than L/N due to the smaller conductor size used for the earth.

Getting in a professional to do the work is a good idea, maybe someone on this forum might be able to help?

 

[pc1966]

Just missed @SparkyChick post!

Also your profile does not indicate area, so if you can post a post code or city/town you might get an offer of help.

 

[Pfeet2]

Thanks @SparkyChick and @pc1966 for the advice, really helpful.

I'm pretty sure there are some other funny bits going on around the house so am leaning towards a professional route this morning and getting it all checked over. I'm in Cumbria (CA11).