Ring vs Radial

[MDJ]

I disagree - plug everything into a ring and it balances itself. Customers don't care about balancing circuits and will plug everything in where they want.

Thats the worse statment I have ever read, anyone who knows about electrical Installation practice would know that several power circuits is more practicable than a single ring, I'm not against rings by the way, I would always have at least 3 in a house, however, for starters you could have several 20 amp 30 MA RCBOs protecting several circuits and the nusience tripping would be a hell of a lot less than on a ring, and also 2-3 sockets max on a radial would illiminate overloading due to the lack of outlets on the circuit, I would suggest 4mm2 radials on 20 amp circuits myself and radials for fridges and freezers seperate again, a ring with a heavy load isn't balanced, it can be overloaded and due to collective earth faults very annoying for the house holder due to nusience tripping, but with several circuits if RCBOs are used the chances of collective earth faults very unlikey and nusience tripping the same.

 

[Fin170]

Several 20a RCBOs using 4mm?

Don't suppose you could share some of your millionaire customers with me could you? :lol:

 

[imago]

and also 2-3 sockets max on a radial would illiminate overloading due to the lack of outlets on the circuit,

but with several circuits if RCBOs are used the chances of collective earth faults very unlikey and nusience tripping the same.

Again the will/stupidy/lack of knowledge of the end user is overlooked. You can't limit the load on a circuit by limiting the number of outlets on it. Anywhere it's deemed necessary will have a double adapter with a couple of six point extension leads plugged into it. Or one long extension lead to an arc welder, or some similar nonsense.

The arguement for several circuits with RCBOs applies equally to a well designed ring arrangement using RCBOs.

Which brings us back to either ring or radial is acceptable and page one of the thread.

 

[MDJ]

I see your first point but will never agree 1 ring is equal to several radials, just impossible IMO, it just doesn't make sence to me and never will.

 

[imago]

I see your first point but will never agree 1 ring is equal to several radials, just impossible IMO, it just doesn't make sence to me and never will.

I'm not saying it's equal in every circumstance, just that it's a 'horses for courses' issue. I use ring and radial circuits with equal enthusiasm as both have their place in a decent installation IMHO.

 

[MDJ]

ok fair enough.

 

[Silly Sausage]

This linear thread is going round in circles... :joker:

 

[imago]

This linear thread is going round in circles... :joker:

That'd make it a ring then?

 

[Adam W]

Thats the worse statment I have ever read, anyone who knows about electrical Installation practice would know that several power circuits is more practicable than a single ring, I'm not against rings by the way, I would always have at least 3 in a house, however, for starters you could have several 20 amp 30 MA RCBOs protecting several circuits and the nusience tripping would be a hell of a lot less than on a ring, and also 2-3 sockets max on a radial would illiminate overloading due to the lack of outlets on the circuit, I would suggest 4mm2 radials on 20 amp circuits myself and radials for fridges and freezers seperate again, a ring with a heavy load isn't balanced, it can be overloaded and due to collective earth faults very annoying for the house holder due to nusience tripping, but with several circuits if RCBOs are used the chances of collective earth faults very unlikey and nusience tripping the same.

Ah well now you're talking about 'nuisance tripping' in which case I would agree. You didn't mention that in the previous post; I was talking about overloading - a customer could happily draw 30A from upstairs or downstairs continuously from any room, while they couldn't with a 20A circuit unless you have one radial per double socket, which seems like a waste of copper and CU space (not to mention money), and unnecessary considering BS1363 plugs contain a maximum 13A fuse.

 

[tigerpaul]

Here is a question for you..
For arguments sake... Consider a standard ring circuit (32a Mcb 2.5mm conductor) It has an additional socket spurred off of one point.
Now imagine the extra spurred socket is wired away from the board, so there are 3 conductors in the Mcb, still conforms to the regs.
So therefore the cable that feeds that spurred socket is protected by a 32a Mcb and it is allowed.
Now disconnect the ring cables.
Suddenly that spur doesn't comply anymore...
Does anyone else find that a little strange?

 

[tigerpaul]

Or to put another way..
A 2.5 radial feeding 1 socket is fed off a 32a Mcb.
"not protected!"
But if you don't have an appropriate Mcb on the van, it doesn't matter, we'll just run in a couple of new legs to a new socket and bobs your uncle it's all tickety boo now because we've changed it to a spur off of a ring and that's fine!

 

[Adam W]

Here is a question for you..
For arguments sake... Consider a standard ring circuit (32a Mcb 2.5mm conductor) It has an additional socket spurred off of one point.
Now imagine the extra spurred socket is wired away from the board, so there are 3 conductors in the Mcb, still conforms to the regs.
So therefore the cable that feeds that spurred socket is protected by a 32a Mcb and it is allowed.
Now disconnect the ring cables.
Suddenly that spur doesn't comply anymore...
Does anyone else find that a little strange?

The maximum you can draw off it continuously is 26A though.
Use your second example of running in an extra leg and you're effectively increasing the CSA - ie you may as well be replacing it for 4mm.

 

[tigerpaul]

No in the 2nd example what I meant was:
Putting into the Mcb, 2 more legs which go to another socket. So that you'd have the original socket fed by one 2.5 and the new one fed by two 2.5s
How does putting the new cables and socket in, increase the safety of the original circuit?

 

[ExArmy]

Or to put another way..
A 2.5 radial feeding 1 socket is fed off a 32a Mcb.
"not protected!"
But if you don't have an appropriate Mcb on the van, it doesn't matter, we'll just run in a couple of new legs to a new socket and bobs your uncle it's all tickety boo now because we've changed it to a spur off of a ring and that's fine!

that is a very long winded way to fix a problem that doesn't exist!

 

[tigerpaul]

It's a hypothetical question..
32a Mcb is overrated for a 2.5 radial, but chuck a couple of cables in and suddenly it's okay..