The Ring is dead, long live the Radial!⚡

[Midwest]

Yeah, I was watching the ideal international sparky championship. Aussie, Canadian, American and a Chinese fella in the final. Someone in the comments section asked where the British entry was. The comments were “Anyone who uses Rings, are not invited” and the like. These foreign morons have no idea of the concept. They probably would have trouble wiring one.

I thought you were going to say a joke; at the sparkie championship, there was an Aussie, Canadian, American & Chinese's sparks in the competition.

When asked, where were the British entries, they said they weren't invited as they would run rings around us.

 

[pc1966]

Real time constraints when carrying out EICR's at acceptable cost mean ring circuits are often not properly verified and the inspector has to make judgement calls on whether the circuit is correctly wired. That said I love testing my own rings and calculating whether measured readings are spot on!
As far as radials go there was a long thread on here a while back where an OP stated rings should be outlawed because they are often abused by Kev the kitchen fitter and DIY Dave, his point was radials are much safer.
But unskilled persons being unable to correctly alter a ring is not a reason for banning it, ban Kev and Dave...not the ring!!
That point of view also ignores the potential danger of a radial. One bad or broken connection of the cpc may result in every downstream point working and apparently ok but not having an earth.

The problem with properly verifying a ring is not lost on a radial either (for the record, I think spurs off a ring are the Devil's work and should be you last resort).

Say you have a 32A radial in 4mm, how often would an EICR check it had not been extended in 2.5mm for much the same risk as a double-spur on a ring?

Yes, the usual radials on 20A might be safe for 2.5mm but it is the same underlying problem - if some idiot has extended a circuit badly it is not always apparent from the readings.

I guess checking the worst case Zs is OK for the MCB is probably good enough for most cases, but complete verification of an unknown is a costly and difficult situation in both cases.

 

[radiohead]

The problem with properly verifying a ring is not lost on a radial either (for the record, I think spurs off a ring are the Devil's work and should be you last resort).

Say you have a 32A radial in 4mm, how often would an EICR check it had not been extended in 2.5mm for much the same risk as a double-spur on a ring?

Yes, the usual radials on 20A might be safe for 2.5mm but it is the same underlying problem - if some idiot has extended a circuit badly it is not always apparent from the readings.

I guess checking the worst case Zs is OK for the MCB is probably good enough for most cases, but complete verification of an unknown is a costly and difficult situation in both cases.

Indeed, and one of my bugbears on this forum is those who advise punters to have an EICR because it will identify any problems. No it wont necessarily.... and those of us tasked with carrying out EICR's are not helped by the creation of unrealistic expectations of what an EICR can identify.

 

[Vortigern]

I think the ring is for the more technical minded. The maths in it are great. Really it is not for amateurs so I can see why dumbing down is the way to go as with so many things today. The ring is dead (as it should be while working on it!) long live the ring! would be the correct use of that paraphrase.

 

[pc1966]

I think the ring is for the more technical minded. The maths in it are great. Really it is not for amateurs so I can see why dumbing down is the way to go as with so many things today.

I don't quite understand that statement.

The "radial" in the general sense might often be used for all sorts of strange loads so calculating its safe parameters is a bit of a challenge at times.

The radial for a couple of 13A sockets is fairly easy but typically you would see 2-3 MCB sizes possibly used, and 1.5 (dodgy) / 2.5 / 4mm choices depending if it is one, a few, a lot of sockets (or quite long).

The RFC on the other hand, if you keep away from the Devil's spurs, is really simple for 99% or so of cases:

• Use 2.5mm cable
• Use a 32A B MCB
• Loop the cable round from MCB, to every 13A socket, back to same MCB
• Keep that length below 96m (or look closely at the OSG & check your DB Ze)

Yes, the RFC is dumb choice if you only have a couple of sockets at a remote-ish area, but for most general house wiring it is simple and effective.

I really think if either of them is difficult for someone to grasp then they ought not to be doing it though! But that applies to a lot of things in life.

 

[Vortigern]

I don't quite understand that statement.

To be honest I was being a bit provocative/sarcastic. I fully agree there is a place for each of the types of circuit. And the radial is essential in a number of cases. What I rail against is the disposal of the ring final circuit in favour of the radial taking over and dispensing with rfc altogether. I don't think people have thought this through actually. So we have a radial as the preferred household circuit. Branching and branches off of the branches, a kind of fractal growth of additions over the years. Now, it is you job to track down a fault. What would you prefer a nightmare of endless branches or a nice orderly ring with a crossover?

 

[pc1966]

Agreed, the problem is the badly-done additions to either type of circuit, not the basic premise.

But you can't make something foolproof as fools are so damn inventive, just look over the "dodgy pictures" thread, etc!

 

[ipf]

Just had a look at the latest results on this poll...not voted myself, by the way.
Ring 27, Rad 5........I wonder how many of those radders have voted for rings too, as should be the case.
For the actual question, it should be 50/50, IMO.... both
On the other hand, I'll bet all the ringers use rads as well, although all the rads don't use rings. So the rads should beat the rings.

It must be getting cold, the rad's have come on and I've got to go, the phones ringing....

 

[Mike Johnson]

I voted for Radials as that is all the French allow, maximum of eight sockets on 1.5mm and twelve sockets on 2.5mm no calculations needed, all specialty outlets to be in 4mm or 6mm according to load, the list of specialty outlets is very long, but includes hob, oven, fridge, freezer, washing machine, tumble dryer.................well you get the idea.

 

[mattg4321]

Running a 4mm2 to supply a domestic fridge seems like a criminal waste of resources.

 

[radiohead]

Running a 4mm2 to supply a domestic fridge seems like a criminal waste of resources.

About a thousand years ago, when I started, local authority spec in schools was a minimum of 4.0mm MICC to any socket, often we were running a radial to a single socket!

 

[pc1966]

About a thousand years ago, when I started, local authority spec in schools was a minimum of 4.0mm MICC to any socket, often we were running a radial to a single socket!

Odd!

Mind you an issue with MICC was folk running in circuits based solely on the high rated current carrying capacity (that running at high temperatures allowed) and not considering higher voltage drop from thinner conductors, perhaps this was some attempt to avoid that issue at a contract level? Or to allow for additional capacity later?

But wastful, compared to simply implementing a correctly designed circuit.

 

[Mike Johnson]

I voted for Radials as that is all the French allow, maximum of eight sockets on 1.5mm and twelve sockets on 2.5mm no calculations needed, all specialty outlets to be in 4mm or 6mm according to load, the list of specialty outlets is very long, but includes hob, oven, fridge, freezer, washing machine, tumble dryer.................well you get the idea.

I did not word that very well, what I should have said was "all specialty outlets to be in 2.5, 4mm or 6mm according to load, sorry about that, it was early.
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I voted for Radials as that is all the French allow, maximum of eight sockets on 1.5mm and twelve sockets on 2.5mm no calculations needed, all specialty outlets to be in 4mm or 6mm according to load, the list of specialty outlets is very long, but includes hob, oven, fridge, freezer, washing machine, tumble dryer.................well you get the idea.

Thinking about it, that post disappeared this morning before I had finished composing it or checking it's content, when I left the Forum the post was not there, that's my excuse and I am sticking to it.

 

[DPG]

On a similar note, is anyone else having keyboard problems on the forum. Money works fine in other apps, but whenever I use the enter or backstage key on here my keyboard disappears. Strange.

 

[Mike Johnson]

There's a rift in the "Space time continuum" on my desk that does that some times, it's either that or the Romulum cloaking device playing up.

 

[telectrix]

There's a rift in the "Space time continuum" on my desk that does that some times, it's either that or the Romulum cloaking device playing up.

or just basic computer witchcraft.

 

[LastManOnline]

The problem with properly verifying a ring is not lost on a radial either (for the record, I think spurs off a ring are the Devil's work and should be you last resort).

Say you have a 32A radial in 4mm, how often would an EICR check it had not been extended in 2.5mm for much the same risk as a double-spur on a ring?

Yes, the usual radials on 20A might be safe for 2.5mm but it is the same underlying problem - if some idiot has extended a circuit badly it is not always apparent from the readings.

I guess checking the worst case Zs is OK for the MCB is probably good enough for most cases, but complete verification of an unknown is a costly and difficult situation in both cases.

"spurs off a ring are the devil, s work" is a comment I would regard as "throwaway" in most cases, but your comments are much too measured and considered for me to take it lightly in your case. Do you really feel so strongly? (I agree by the way but would, nt use the same language). Or have you been swayed by John Ward who used the phrase "devil's work" in relation to ring circuits.
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Indeed, and one of my bugbears on this forum is those who advise punters to have an EICR because it will identify any problems. No it wont necessarily.... and those of us tasked with carrying out EICR's are not helped by the creation of unrealistic expectations of what an EICR can identify.

Agreed. I often remind customers that when testing we do not have a "crystal ball" and that our meters are limited in what they can tell us. I maintain that the "visual test" is still the single most important o E we carry out

 

[ipf]

I maintain that the "visual test" is still the single most important o E we carry out

Any inspector who doesn't agree with that shouldn't be allowed anywhere near an electrical installation.......unless they're testing in braille, of course.

 

[pc1966]

"spurs off a ring are the devil, s work" is a comment I would regard as "throwaway" in most cases, but your comments are much too measured and considered for me to take it lightly in your case. Do you really feel so strongly

I can see why they are allowed, as they don't impact on the safety of a ring when done correctly.

But my bone of contention is the same as a badly modified radial circuit - you have far, far, more things that can be done badly where more than one 13A socket has been spurred off, etc. Also it degrades the elegant testability of a ring (the figure-of-8 style) as a higher R at some point might be bad connections/socket, or it could just be a run of cable on a spur.

So to me an installation with spurs is fundamentally a bad starting point (really you could not run the ring to/from that point, or maybe just a radial for that odd load?) and once folk start modifying it you get in to the test/verification nightmare.

But that is not an attribute of ring per se as if you do dumb stuff to a radial (i.e. creating a the Christmas tree circuit) you get exactly the same issues of being able to adequately confirm it is all safe.

 

[SJD]

Sometimes, with a physically long ring - e.g. because the circuit is some way from the distribution board (say in a large mansion) - I've found a spur or two can help keep the length of the ring down, and make the difference between a comfortable compliant and perhaps non-compliant circuit.

I'm also a fan of a spur at the origin on an RFC, where appropriate!