Radials and Rings in Ireland

Solair

A British DIY electrical expert I know who has recently bought a house in Ireland asked me a few questions about rings and radials here, he is totally confused and a bit 'shocked' that Irish regulations aren't a carbon copy of UK regulations.

What he's confused about is that the 20A circuits in his house in Cork appear to be radials, he was expecting them to be rings as in the UK.

Do we use 20A rings?

The only rings I have come across here are 32A

He also had no idea why some socket circuits were 16A radial.

While I have a fairly good idea of the regulations, I don't own a copy of the ETCI guides.

What are the 'norms' here?

One of the oddest ones I've come across was a house in suburban Cork which still had 16A 'schuko' sockets! i.e. an old 1950s version of one of these :

Davy

The norms would be changed since that house was build. THIS thread gives everything about the modern normal wiring.


The Irish regs would be a very similar to the uk, but better. They have a higher spec and would be more safety focused than the uk imo. And rings are definitely a thing of the past!

davelerave

the radial is 16/20 and the ring should be 32.nothing to be shocked about .the ring has pros and cons. but is being phased out in favour of radials afaik.

Solair

Now I understand his confusion, apparently there's an option in the UK for a 4mm2 32A radial too, which is occasionally used.

I was wondering what he was on about 20A rings.

2011

Now I understand his confusion, apparently there's an option in the UK for a 4mm2 32A radial too, which is occasionally used.

Rewireable fuses are even allowed in the UK. It is a completley different system with some similarities.

I was wondering what he was on about 20A rings

32A ring socket circuits are the only ones permitted here at present. Radials can be 16, 20 and 25A.

davelerave

not sure about 25amp radials( in 2.5 anyway?)4sq radial socket ccts would be handy here when the ring cct is gone.

2011

not sure about 25amp radials

You are permitted, but it is not the norm.
A bit like you can have 100 sockets on the same ring circuit within 10m^2, not normal but it is permitted.

davelerave

you sure its allowed

the iceman come

since when were 20 amp ring circuits not allowed in Ireland? still commonly used by my employer:rolleyes:

davelerave

the iceman come wrote: »

since when were 20 amp ring circuits not allowed in Ireland? still commonly used by my employer:rolleyes:

it's not dangerous but it's bad practise as you're derating the cct

2011

since when were 20 amp ring circuits not allowed in Ireland? still commonly used by my employer

I dont know the date! But certainly for over 10 years now it is against ETCI regulations.

I saw RECI make a contractor of theirs change it recently during an inspection.

davelerave

yes reci wont allow 20s or even 25s for domestic rings

RoundyMooney

Indeed. I freely admit I don't do much in the domestic area, but I'd appreciate any input:

What are the main risks associated with derating a circuit? I still do 20A rings when I do, but I'd consider it erring on the side of caution? To me the main risk of a ring circuit is losing one leg, be it phase or neutral, unwittingly. In that case, a 32A will be above and beyond the rating of a single run of 2.5?

davelerave

the derating could be an issue where there was a risk of tripping the 20amp such as kitchen or utilty ring and also the number of rooms or floor area covered by this 20amp ring might exceed that specified for a 20amp radial .the benefits of increased overall csa and reduced voltage-drop are still there regardless .reci would say to fit the appropriate mcb ie:32amp
otherwise wire in radial

RoundyMooney

I get the issue in the regs regarding no. of outlets etc., Dave

I'm still curious though as to why derating is a problem, aside from possibly over burdening the 20A fuseway by virtue of too many outlets.

It's quite easy to overload a 20A MCB, to follow your point. My place is old school, to a degree with a combined kitchen and utility ring (predating the new regs) on a 20A. Tumble drier, machine, kettle and dishwasher will kill it with napalm. Not to mind wine coolers and all the other knick knacks...;)

Need to change it for a 32, actually, probably when I get around to doing that switch fuse...

2011

RoundyMooney:

I'm still curious though as to why derating is a problem

What I am sure of is that it is against regulations. Why it is not allowed I can only guess. My guess is the following:

As you know derateing the circuit can cause nuisance tripping. Continual nuisance tripping has been known to encourage people to do stupid and dangerous things. For example: We have all seen cases of people wrapping tin foil around fuses etc.

People that find that their 20A MCB supplying 30 sockets on a ring circuit may therfore do something like link out the MCB.

+ 1 davelerave.