Have the rules for ring mains changed over the years?

[Lucien Nunes]

I really don't know what the point of this thread is. But I do know:

• A final circuit is one that feeds a load or loads, rather than another level of distribution
• When the ring final circuit was introduced in 1947, it was acceptable and correct to call it a ring main, and the term was used in official documentation. The ring concept was already in use in the distribution cabling of the DNO's works, which were 'mains' and hence those arranged as rings were 'ring mains.'
• The ring final circuit is not obsolete and there are some tasks for which it is more suitable than the 20A radial. Both configurations have always been recognised for socket-outlet circuits for general use, although the 13A fused plug and 30A final circuit were parts of the same system concept and the ring is a convenient way to provide a 30A circuit without using 30A-rated cable.

And 101 other compelling reasons. I think. Actually, what was the question?

 

[mainline]

It seems the OP has given up.

 

[OnlQQker]

I never understood people that say 'Near Miss'
Like when planes get to close and they report it as a 'Near Miss'

If I was looking up and saw 2 planes that was extremely close together. I would tell everybody afterwards that the 2 planes nearly hit each other, not that they nearly missed each other.

Bit off topic, but as long as you know what it means, doesn't really matter about anything else!

 

[snowhead]

You’re trained to 16th Ed, and you don’t know what a radial is?

I suspect he meant What is a Radial called now, if a Ring Main is now called a Ring Final

 

[OnlQQker]

No need for Rings anymore Imo , its one thing I would do away with now

Just install 20amp radials

This is exactly how a surgeon working in a hospital, wired up David Tomlinson's fusebox (x4 12 ways = 48 ways) in his house in 1960. I had never seen so many wires in my life. But the beauty of it was, only one appliance would go off, even the lights was one at a time.

Though something else didn't look right, the hifi center under the stares was wired up with doorbell cable, one 2.5 cable through the staircase ceiling, then door bell cable from that to each of the 230v sockets (x3) after that!

 

[7029 dave]

I still like the flexibility of a RFC, as for fault finding them if you know what you are doing it is quite simple.
I have traced a faulty section down between two socket outlets in less than 2hrs, thats from coming through the front door and leaving, temp repair made dropped the mcd down to 20A because had to break the ring convert to radials temporary. Went back when could take the floor boards up in the area of the damaged section JB full of water.

 

[mainline]

It's not simple when you have a 3-story house with one ring and hidden JBs under floors with numerous spurs and cross connections etc.

 

[7029 dave]

It's not simple when you have a 3-story house with one ring and hidden JBs under floors with numerous spurs and cross connections etc.

Well that would get rewired into separate RFC circuits for starters

 

[littlespark]

It's not simple when you have a 3-story house with one ring and hidden JBs under floors with numerous spurs and cross connections etc.

Could be same with a radial and multiple branches. Still have to find the fault and disconnect.
But with an rfc, you might not lose the function of the majority of the circuit until repaired.

I must admit, when I trained ‘86 to ‘90 the journeymen I was with were really old school.
Sockets were always on a ring, unless it was only one on the circuit.
Radials were limited to individual points, such as. Cooker, shower, immersion, heaters, etc
It was very rare to find more than one point on a radial circuit

 

[7029 dave]

Could be same with a radial and multiple branches. Still have to find the fault and disconnect.
But with an rfc, you might not lose the function of the majority of the circuit until repaired.

I must admit, when I trained ‘86 to ‘90 the journeymen I was with were really old school.
Sockets were always on a ring, unless it was only one on the circuit.
Radials were limited to individual points, such as. Cooker, shower, immersion, heaters, etc
It was very rare to find more than one point on a radial circuit

When at college 1980 ish 14 ed/ 15 ed not that the regs stated it I think, but the electrical craft principles book we studied from actually stated max numbers of sockets put on radials. Well it certainly weren't unlimited remember that much.

 

[Dustydazzler]

When at college 1980 ish 14 ed/ 15 ed not that the regs stated it I think, but the electrical craft principles book we studied from actually stated max numbers of sockets put on radials. Well it certainly weren't unlimited remember that much.

Have no idea how true but the old boys on-site were adamant you should only put 4 sockets max on a 20a radial

 

[mainline]

When at college 1980 ish 14 ed/ 15 ed not that the regs stated it I think, but the electrical craft principles book we studied from actually stated max numbers of sockets put on radials. Well it certainly weren't unlimited remember that much.

2.5mm, 20 amp protective device, 50 square metres.

 

[7029 dave]

Have no idea how true but the old boys on-site were adamant you should only put 4 sockets max on a 20a radial

Yeah something like 3 doubles or 6 singles

 

[westward10]

None of these requirements for radials or ring finals have ever been Regulations just informative in the Appendices.

 

[7029 dave]

None of these requirements for radials or ring finals have ever been Regulations just informative in the Appendices.

Yup in my view good working practices, unlimited 20A radials IMO is just ridiculous