Ring, Radial or Both

[bigd]

Guys (and girls),

Just looking for a bit of advice regarding a re-wire, which I intend to use for my Elecsa Assessment.

I've been quite fortunate that I have a friend who's allowed me to complete a full re-wire on a small 2 bedroomed house. The house has been unoccupied and he's not in a rush to get the re-wire completed, so I've been able to gets lots of advice and take my time with the re-wire.

The question I have is regarding the new extension he's having built at the back. Its going to incorporate a medium sized kitchen and a small day room. I need some advice regarding whether I should be using a ring or radial circuit for the extension.

Obviously the cooker will be on a separate circuit. But what about sockets and fused spurs (fridge, dishwasher etc)? My course instructors (yes, yes I know zero to electrician in 4 weeks) preach the gospel of radial circuits. Ring circuits are dead, radials are the future and so on.....

But it seems to me that rings are an elegant solution to my problem.

I guess I'll be installing approx 12 double sockets in the whole of the extension, plus a dishwasher, fridge/freezer, dishwasher, tumble drier

What are your views?

 

[davelerave]

not saying rings are dangerous

i use them myself

engineer 54-the drinking smilie is to signify that im drinking btw:yesnod:

i just discovered it but ive lost it again?where is it

 

[davelerave]

maybe the domestic ring final will eventually disappear- it's being phased out over here

there'll be still be 'ring finals' for com/ind and 'ring mains'

 

[Engineer54]

radials are safer because faults are easier to identify for the end user (ordinary persons). So in the scenario of a fault, a radial IS inherently safer.
ring finals were introduced for one reason only, and it wasn't safety.

I have never used ease of testing as a reason of choice.


just checked the video, where is the claim that its easier to test?

What video ??

Isn't that a part of what electricians are trained for, finding faults on electrical circuits, or are we now advocating ''ordinary person's'' should be fault finding electrical circuits...WOW!!..??

So tell me, what is so unsafe about a ring circuit that has been correctly designed and installed??


The ring circuit came about for many reasons, not just one, as so many people have been lead to believe....

 

[Paul.M]

I will duck and dive away from the handbags and try to help the op. Regarding the kitchen appliances, there's not a great load for them so you can go with either. Next thing to think about is additions to your circuit, is it possible that someone will need to extend it later on? How many plug in appliances could be used at any one time? (Your still thinking that you can still choose either). Now think about the cable run itself, you've still got to get to each socket/contact switch but is it easier to do it with a ring or radial? If the last socket on this circuit is close to the c/u use a ring. If the last point is the same distance away from the c/u why use a ring, just install a radial (it may be an L shaped kitchen) think about the cost to you and the customer, if all the loading calcs are ok for both ask yourself which will take less time and money to install? Although that as your first answer to the assessor won't go down to well. End of the day we have two tools/methods we can use and if you ask the right questions to yourself you will design the correct circuit. What does the customer want? What's its use? What's the load? Where is the cable route? Are the calcs ok? What's the difference in time and costs? Oh, as for the day room just stick it on a radial .

 

[alli]

I heard that the use of a ring final circuit of 2.5mm was used afterthe war when supplies of metals where low, the installation of a ring cct in a domestichouse would use less copper than running 4mm radials!

 

[Sparky Ninja]

God help our industry!!! All your churning out now i'm afraid, are badly trained Domestic installers from what i can see... And yes i DO worry about our industry!!!

Please PM which one of my students you have met.

You need to calm down a bit.



For the record, I teach 2330 and 2357 on a three year course as well, and they are told the same thing about the benefits of choosing a radial over a ring final.

 

[Sparky Ninja]

or are we now advocating ''ordinary person's'' should be fault finding electrical circuits...WOW!!..??

Oh come on... that's a complete misenterpretation of what i said.
If a circuit is broken on a radial, 'ordinary person' identifies the loss of power and gets the electrician in.
If an open circuit occurs on a ring final, 'ordinary person' doesn't identify as no loss of power occurs and so the cables potentially overload.

I can't believe I've had to explain that.

So tell me, what is so unsafe about a ring circuit that has been correctly designed and installed??

The day it's installed, nothing. In 'x' amount of years, any number of factors can occur that will possibly affect the integrity of the ring final. That's why we carry out periodics.

The ring circuit came about for many reasons, not just one, as so many people have been lead to believe....

Please share..

 

[Amp David]

not saying rings are dangerous

engineer 54-the drinking smilie is to signify that im drinking btw
:yesnod:

Dave mate, only those with a sense of humor would understand that though:yesnod:

 

[Silly Sausage]

I'm not going to get involved in the old Ring v Radial argument, but...

if you get a broken CPC on a radial every outlet beyond has no earth (most obvious statement of the day!), at least with a ring you've still got an earth.

This must have been done to death before, any links to previous threads?

 

[Amp David]

Why on earth will the increased use in radial crush our industry.

Always seem like old dog and new tricks to me when someone decides to overly argue and defend something.

 

[SW1970]

Good point! Supplies of metal might not be low but they're blinkin expensive at the moment!

I heard that the use of a ring final circuit of 2.5mm was used afterthe war when supplies of metals where low, the installation of a ring cct in a domestichouse would use less copper than running 4mm radials!

 

[Sparky Ninja]

I'm not going to get involved in the old Ring v Radial argument, but...

if you get a broken CPC on a radial every outlet beyond has no earth (most obvious statement of the day!), at least with a ring you've still got an earth.

This must have been done to death before, any links to previous threads?

Agreed that's a good point. An RCD however, if installed, will provide the additional protection required for this unless you were unfortunate to touch live conductors simeltaneously (most unlikely).
Whilst potential overload from an open ring final wont be protected by an RCD.

 

[Silly Sausage]

Haha...fair point, didn't consider RCD.

As an aside, if you were to touch both lives simultaneously on an RCD protected circuit do you think you'd get enough earth leakage for it to trip?

 

[roukel01]

Well just to and my 10 pence worth. The inspector that comes to see me every year from Elecsa told me he still prefers to see ring circuits.

oh and next you're going to tell me to stop earthing my metal back boxes!!!

 

[truckster]

Haha...fair point, didn't consider RCD.

As an aside, if you were to touch both lives simultaneously on an RCD protected circuit do you think you'd get enough earth leakage for it to trip?

Bit of trouser leakage maybe?