They'll find a way, they always do.8. integrity of the original circuit layout is less likely to be abused or altered by homeowner /diyer.
They'll find a way, they always do.
well so long as no-one takes my cheeky challenge too seriously , it may serve readers to think about all the design options in even simple domestic scenarios.
Rings...
If you get a break in the cpc, the whole cct still has an earth; cpc break on a radial, no earth beyond that point.
also takes much less typing for a convincing argument![]()
i knew this as well widdler
one of the rings biggest advantages is also one of its biggest weaknesses.
but archy wasnt really up for reasoned debate lol.
If your +1 for a ring final requires a fault to be in the radial then look at it this way.
Radial.
Break in cpc = socket outlet with no cpc = risk of electric shock = RCD* disconnect when imbalance occurs.
Ring final.
Break in ring final = no detection of fault as only one line conductor has slipped out = 2 x 2.5mm cables with a best case scenario current carrying capacity of 27A (surface clipped) protected by a 32A MCB = Overloaded cable = House Fire = Death
*assuming this argument refers to scenarios where 30mA RCD's are required for socket outlets <20A.
:30::30::30::30::30::30::30::30:
A split ring, how often are you going to get >>20A down 1 leg for a significant length of time that it's going to fry a cable?
well if its a kitchen ring that has an undetected split , with the kettle , washing machine , dishwasher and tumble dryer and fan oven all fitted all close together on 1 wall of the kitchen , then its going to happen very frequently and for long periods.
10. If the CPC breaks at some point you still have the CPC from the other leg.radials - pro's
1. no consideration needs to be given to balancing of loads across 2 legs
In a domestic situation you can't be sure of what's going to be plugged in where so that's not a consideration; if anything having a 32A ring makes that more flexible. On a radial the highest current using equipment should be plugged in to the nearest point to the CU which makes it more difficult with a radial, while with a ring you have 2 ways back to the CU.
2. Quicker to test
You still have to plug in to each socket. End to end doesn't take long, quick calculation and you can work out what you should be getting at each socket. Anyone who can't wrap their head around ring final testing probably shouldn't be doing the job in the first place.
3. Quicker to install
Again if you're reducing the capacity from 32A to 20A and thereby cutting out the last leg back to the CU this might be true, but it's not a true comparison. 2.5mm is quicker and easier to install than 4mm.
4. More flexible in cable layout to each point
You still need to run 2 cables either way.
5. Easier to add extra points at later date and with fewer restrictions with regards to where you can extend the circuit
You can spur off a ring. If the circuit is properly designed in the first place you shouldn't need to; a 'tree' arrangement would be a nightmare to find faults on.
6. Less chance of cross connections at the CU
Not with T&E, which would most likely be used in a domestic situation. If you're talking about singles you could say that about cross connection with other circuits.
7. Saves on cable when floors of a property dont require 32A of power , eg 2 bed terrace houses.
As I've said, it depends on the layout of the property. You could have one ring for all the sockets (maybe an extra cct for the kitchen) and split the lighting circuits differently.
8. integrity of the original circuit layout is less likely to be abused or altered by homeowner /diyer.
You could say that about any circuit. You can't account for what a DIYer/DIer is going to do after you've left, but an end to end at the EICR should pick this up.
9. Greater current capacity for the equivalent amount of cable used , eg
how have a ring main for the ground floor of a house - remove the midpoint cable and this leaves you with 2* 20amp radials - so you have a net gain of 8A for exactly no more cable.
You could say the ring option is 'over-engineered' which will give you some extra headroom for volt drop. Remember with a ring you're not splitting the circuit into 2 radials (although you have the option at a later date) so you can allow for greater diversity.
You've just picked up a few reels of 4mil cheap in Dudley then?![]()
You need to use common sense then.
People are just frustrating!
So long as power comes out of the socket the customer doesn’t give a ---- how it got there.
My own view is the radial is gaining popularity because of inexperienced installers. Be they electricians or DI’s (what ever one of them is).
I'm sure this subject has been discussed by much higher beings than the likes of us
It has, and I am.
Remember the whole of the wall power accessory catalogue is based on and around the Ring Final Circuit!!!!
10. If the CPC breaks at some point you still have the CPC from the other leg.
and if its a break in the L or N then you have a fault which remains undetected as all points remain working but all the while leaving potential for certain sections of cable to exceed their normal current rating , at the very least shortning the expected lifespan of the cable.
11. You have the option at a later date to split the ring to make 2 20A radials for whatever reason.
well splitting a ring can be a total faff if the sockets arent close together , nowhere near as flexible as being able to add a point from any other point as you can with a radial - your comment just reinforces my earlier advantage.
12. With a ring you can draw a similar current using less ways on the board.
hardly a problem when sparks are banging in 10 way boards in 2-3 bed properties.
anyway , a greater division of circuits reduces inconvience when a circuit trips.
I said I'd add an extra 1 - turns out I found an extra 3!
That said, I'm not against radials, but they need to be used in an appropriate situation and not blindly used because they're 'the modern way of doing things'.
Sorry for the delay in reply - I went to the pub with my mate instead of sitting at home talking shop on the internet, although to be fair he's a spark as well so we did talk shop.