Ring mains? Is this true?

[malcolmsanford]

all these protons and neutrons work better with a bit of heat up them lads .................

 

[oldtimer]

As we get nearer to "European Harmonisation" the only thing left to phase out is ring final circuits and the 13A plug top so look out in the 10 years also someon has invented a 13A plug top that a european plug fits inside.

And why 10 years well even the scheme providor know and realise that this is the next big move ie new Big Blue Book Blue onsite guide but after the green phase in they will have to wait a while

 

[Engineer54]

We always wire, if not using power trac systems a 4mm ring, without RCD protection.

If your using a radial circuit for high protective current equipment you will need to have your CPC 10mm unless you run a 4mm CPC out in your and a sepearte 6mm back.

By wiring it in a ring you can drastically reduce cable size. You can in fact wire it in 2.5mm as a conventional ring using T+E or singles but we just prefer 4mm.

Quite agree, RFCs are always going to be a better solution on circuits supplying IT loads. And as you say, going a cable size higher also makes a lot of sense on IT installations...

EDIT.... Forgot to mention, ....Not with T&E type cables, the CPC must be the same size as the line conductors if using a multi core cable!!

 

[Amp David]

Only reason for scrapping the good old ring is because the Electrical Trainee don't know how to test em!!!

 

[telectrix]

RFCs have their place. so do radials. F' rinstance, i would not install a RFC to 3 bedrooms that only pulled 5A for tellys etc. then again, i would not install a radial to feed a washing machine, dishwasher, tumble dryer, kettle, etc. common sense is the rule .

 

[Silly Sausage]

The problem I can think of with RFCs is that breaks in any of the conductors won't reveal themselves in normal service, only by testing.
A single break in L or N and you've essentially got 2 undersized radials on 32A breaker.

 

[Engineer54]

Same old story that comes around on a regular basis, and normally started by the incompetent, who neither know how to test or fault find a RFC, or by lecturers that find it too tiresome to teach the unique subtleties of RFCs to the short-course students!!

 

[jase]

Rings are still ok. But I always use radials now. Even on kitchens, I just have two radials

I was thinking of doing this in my next re-wire hopefully sometime in march, how do you divide it up? i was thinking of doing sockets on one and appliances on another, or do you reckon by having appliances all on one radial that would be overload?

 

[Silly Sausage]

Same old story that comes around on a regular basis, and normally started by the incompetent, who neither know how to test or fault find a RFC, or by lecturers that find it too tiresome to teach the unique subtleties of RFCs to the short-course students!!

I'd like to think that's not the case. All the C&G coures I've done at North Trafford College were given by ex Electricians and, overall, they were pretty good. Got me through all the ones I did anyway.

 

[Knobhead]

common sense is the rule .

Unfortunately something that is sadly lacking now a days.

If faced with an install now* I would go for either all rings or all radials not a mixture of both. That said my preference would be for rings every time. OK economics come in to it but I’d rather not compromise.

* Just glad I stuck to industrial stuff.

 

[telectrix]

I was thinking of doing this in my next re-wire hopefully sometime in march, how do you divide it up? i was thinking of doing sockets on one and appliances on another, or do you reckon by having appliances all on one radial that would be overload?

that's OK, but i would use 4mm for the appliance radial, feeding 20A 2 polo grid switches, 32A MCB.

 

[i=p/u]

job im on at moment , i was looking at circuit sheet and they have wired the ring final circuits in 4mm, and the best thing about someone has sneaked in at night or weekend and cut all cables up short, taken all lables off... lol

 

[jase]

o it would be best to split it up so that there are only half the number of sockets and half the number of appliances on each radial in order to use 2.5mm? i jusyt cant stand the idea of terminating 3 4mms at the dp switches!!

 

[i=p/u]

id assume the 4mm is incase the ring was broken

 

[telectrix]

sounds like plasterers have visited