Ring mains? Is this true?

[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

 

[i=p/u]

nah, they have cut off lables of maybe 40 ciruits, just a big bunch of brown/blue/green cables sitting, lowsey in one sense

 

[highspark]

In most kitchens you have a microwave, toaster and kettle on one side and on the other washing machine, tumble drier and dishwasher etc. I just split them down each side of the room! 20A 2.5mm radials

 

[i=p/u]

well i put them all on there own circuit, to minimize the forever comming fazult

 

[ackbarthestar]

Hi guys,
I have Hurd a few times now that ring mains will soon be fazed out due to the risk of danger if the ring is split! Is it now advisable to just install radial circuits?

Thanks for your help

Yep I've noticed that the story of rings go round and round, but good grief, I wouldn't want anybody splitting my ring !

I would suggest this is anti-ring propaganda, since the amended regs continue to recognize them, albeit given a new number to distinguish them from the harmonized numbering system. They will, no doubt, be forgotten by the uninitiated and those employed in basic domestic installations, with the use of double pole RCBOs, radials supplying dedicated appliances, reduction in the loading of sockets, ease of wiring and testing.

But never forget, ring final circuits are a useful circuit design method for reducing volt drop on long runs, and will continue to be used by designers who actually understand their principle of operation.....

 

[djlander]

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 would just like to point out that i am not imcompetent and i know how to test and fault find! I only asked the origanl question as i have hurd it twice and once by a lecturer, i just wanted to know what you all thought,


i did a 5 year electrical apperenticeship, won a ECA electrical apperentice of the year award, had 8 years on the job experience but my career took a diffrent route for 2 years away from electrics and now just got my quifations upto date and slowly moving back to electrics,

when you have been out the game for a few years and alot of regs have changed, some times when you hear things also from a lecturer you have to ask questions to find out what other people think, this dose not make you incompetent!!!!

 

[telectrix]

dj., eng54. was not suggesting that you were incompetent. he said the rumours were normally started by incompetents etc.

 

[Engineer54]

I would just like to point out that i am not imcompetent and i know how to test and fault find! I only asked the origanl question as i have hurd it twice and once by a lecturer, i just wanted to know what you all thought,


i did a 5 year electrical apperenticeship, won a ECA electrical apperentice of the year award, had 8 years on the job experience but my career took a diffrent route for 2 years away from electrics and now just got my quifations upto date and slowly moving back to electrics,

when you have been out the game for a few years and alot of regs have changed, some times when you hear things also from a lecturer you have to ask questions to find out what other people think, this dose not make you incompetent!!!!

Exactly as Tel stated, wasn't thinking or talking about you at all. Just stating how these rounds of ring demise myths generally get started....

 

[hermetic]

It's been in discussions for many years now. I myself always raise awareness to delegates about the considerations that are made for this to be an issue.
The last time I brought it up with Geoff Cronshaw I got feedback that the consideration would be to restrict them only to installations under the control of skilled/instructed persons.

I personally don't think they will ever remove the ring final circuit. If they were, it would require an incident of some kind directly resulting from the area of concern that would motivate the change. IMO

Hermetic lolz

 

[supasparxs]

i would use radials , no more than 10 IT% items per circuit. will you have RCD protection? if so leakage could be a problem, also hi integrity earthing is desirable.

I understood the issue with earth leakage on IT equipment was due the the CRT monitors being cr@p
as everyone uses LCD monitors now it wasn't an issue?

 

[Silly Sausage]

I understood the issue with earth leakage on IT equipment was due the the CRT monitors being cr@p
as everyone uses LCD monitors now it wasn't an issue?

I've always thought it was the mains filters on the system units.