its not a proper ring!

[stevie2011]

In a domestic, none of the 3 ring mains comply with the 0.05 difference between sockets, some readings varied drastically, anyway I'm sure they're not proper rings, rewiring them is not an option. Could I just fuse it down to a 20amp breaker and leave both tails in the MCB or would I have to leave one out and put it in connector block?

I think ring mains shouldn't be allowed in places that don't get regular periodic inspections, (such as domestic) but anyway thoughts?

 

[Engineer54]

One thing to remember when using 4mm for a radial final circuit, is that there is little chance of adding a extra socket from the accessible outlet box. As most accessory cable termination connections, are at best only 10mm. Not unless some stands are cut from the existing 4mm cables, and you can bet that some Will!!! lol!!!

 

[stevie2011]

Why are you trying to label and restrict uses for final circuits here?? You design and install a final circuit as to the requirement of the installation, and for no other reason. There are up sides and down sides to both ring and radial final circuits.

This old chestnut about breaks in ring finals, is what many highlight, in reality they are about as common as a radial losing it's CPC along the line, ...Rare!!!

I can't really argue with your point, I just don't like the idea that the cross sectional area of the cable is sufficient for the rated current of the protective device because it is connected round in a ring. If you needed the extra juice why not have that room have two radials rated at 20A.

Can be easier to fault find on a radial too, any problems with a radial and matey boy from the video can probably localize it easier with his 3 green light socket tester lol.

 

[Engineer54]

Well i like the idea very much, and it's been satisfying installation needs for a good many years.
As i've stipulated here before, types of final circuits should not be provided based on ease of fault finding for the electrician, but on design and suitability for it's intended use...

 

[stevie2011]

my last note about fault finding was a joke, but as I said I can't really argue with you, as my point was about preference. I just don't often see the need for them in many circumstances when a radial would have done fine, if not better for the intended use. and don't like the idea of a ring not being looked at by an electrician in 40 years which is not uncommon, because if something, however unlikely goes wrong, its more likely to go unnoticed. I don't hear of many electrical fires that happen because a ring overheated but its just how I feel about them. There is probably a place where a ring might be an option, like one that the client intends to run a couple of 3 kW portable heaters or something.

 

[Engineer54]

That's just the point, ....Who knows what the householder is going to plug into a final circuit over the coming years. A ring final is better at catering for those unknowns, than a sometimes restricted radial final...

Some installations do go untested for 40 years, but that's nowhere near as common these days, as it was in the past. So most installations these days and in the future will i feel, be tested far more often, as homeowners move up and down the property ladder...

 

[Engineer54]

Another issue with rings is if any alterations/additions have been carelessly done and a "ring within a ring" is the result....leading to overloaded portions with the resultant overheating etc......

Hopefully not by a qualified electrician!!!

 

[Geordie Spark]

hahaha, I love that video. "but all the sockets would still work"

and "I have this tester, if you get 3 green lights it works"

hahahaha love it.

Mine has 3 red lights :devilish: