RCBOs

Fortywatt

RCBOs for domestic in Ireland generally seem to be two-pole and take up two ways in the consumer unit. I have the impression that in the UK they use single pole RCBOs (with flying neutral and functional earth wire), taking up one way and so potentially saving a considerable amount of space. Is there a problem with using single pole in Ireland?

M cebee

Fortywatt wrote: »

RCBOs for domestic in Ireland generally seem to be two-pole and take up two ways in the consumer unit. I have the impression that in the UK they use single pole RCBOs (with flying neutral and functional earth wire), taking up one way and so potentially saving a considerable amount of space. Is there a problem with using single pole in Ireland?

i don't think there's a problem as we're TN here.
The DP are prob a better job though

2011

+1 for TN-S and TN-C-S

However the RCD needs to switch the neutral when it is part of a fire protection system.

M cebee

TT
fire protection

- if you have 2 in series you need DP downstream afaik to clear the N fault

do suppliers here stock them at all?

liveandnetural

Fortywatt wrote: »

RCBOs for domestic in Ireland generally seem to be two-pole and take up two ways in the consumer unit. I have the impression that in the UK they use single pole RCBOs (with flying neutral and functional earth wire), taking up one way and so potentially saving a considerable amount of space. Is there a problem with using single pole in Ireland?

i think its a single mod rcob rather that a single pole your talking about

using either of these theres no problems
http://www.meteorelectrical.com/garo-20-amp-30ma-single-pole-rcbo-type-c.html
http://www.meteorelectrical.com/garo-20-amp-30ma-1-module-rcbo-type-c.html

M cebee

handy enough
is there a busbar available for the single mod DP ?

Fortywatt

I don't think the single-mods switch the neutral so then they won't be DP in terms of cutting both supply and neutral.

I take it the single-mod can simply replace an MCB so there shouldn't be an issue with the busbar.

The two-mod double-pole raises issues with the busbar because you have a neutral connection at the bottom so you have to cut a prong off the busbar to take the neutral. Not the neatest unless the RCBO is at the end of the busbar, when you can just cut the busbar. Suppose you could use flex instead of busbar if you had two RCBOs side by side.

Looking at it again in the light of the replies, another issue is that the height of the single-mod RCBO means that it probably won't fit unless it's on the top row of the consumer unit.

2011

Fortywatt wrote: »

The two-mod double-pole raises issues with the busbar because you have a neutral connection at the bottom so you have to cut a prong off the busbar to take the neutral.

There is a busbar made especially for supplying both phase and neutral to a row RCBOs.

Have a look at the 2 pole, 2 step busbar here

M cebee

Fortywatt wrote: »

I don't think the single-mods switch the neutral so then they won't be DP in terms of cutting both supply and neutral.

I take it the single-mod can simply replace an MCB so there shouldn't be an issue with the busbar.

The two-mod double-pole raises issues with the busbar because you have a neutral connection at the bottom so you have to cut a prong off the busbar to take the neutral. Not the neatest unless the RCBO is at the end of the busbar, when you can just cut the busbar. Suppose you could use flex instead of busbar if you had two RCBOs side by side.

Looking at it again in the light of the replies, another issue is that the height of the single-mod RCBO means that it probably won't fit unless it's on the top row of the consumer unit.

-liveandneutrals links show 2 different types of single mod rcbo(sp and dp)

-there's no issue with 2 mod DP busbar
theres a specific busbar for the rcbo brand

Fortywatt

Sorry, I should have followed up those links properly. Didn't pick up on there being single-mod DPs even though it was being pointed out to me. And I didn't know there was special busbar for DP RCBOs.

Thanks all. I'm much better informed now. Reckon RCBOs are the thing of the future - looks like they're more or less mandatory for bathrooms already. If only the price would come down a bit.

Bruthal

Fortywatt wrote: »

Reckon RCBOs are the thing of the future

They probably are alright. They make connecting circuits easier as well.

M cebee

Fortywatt wrote: »

Sorry, I should have followed up those links properly. Didn't pick up on there being single-mod DPs even though it was being pointed out to me. And I didn't know there was special busbar for DP RCBOs.

Thanks all. I'm much better informed now. Reckon RCBOs are the thing of the future - looks like they're more or less mandatory for bathrooms already. If only the price would come down a bit.

there's also 2 types of busbar for DP rcbo's

1P and 3P depending on the distribution board

salmocab

The single mod rcbo,s can be a bugger to put in as they are longer than mcb,s so can be very tight when fitting into a multi row board

M cebee

salmocab wrote: »

The single mod rcbo,s can be a bugger to put in as they are longer than mcb,s so can be very tight when fitting into a multi row board

ya that's a point

i wouldn't be bothering with the SP and flylead anyhow-maybe the single mod DP

-i wonder if the DP has what's called a 'switched' N pole rather than a 'rated' pole

http://www.etci.ie/docs/ET214.pdf 3.7

Bruthal

M cebee wrote: »

ya that's a point

i wouldn't be bothering with the SP and flylead anyhow-maybe the single mod DP

-i wonder if the DP has what's called a 'switched' N pole rather than a 'rated' pole

http://www.etci.ie/docs/ET214.pdf 3.7

Id say the standard ones are rated poles if both poles operate together. Havent read the link but that would seem likely.

M cebee

the 2mod are both rated poles afaik
i'm not sure on the single mod

Poles and Number of Poles
The poles of an RCD may be one of three types:
i) A solid neutral pole – a solid neutral conductor that has no contacts.
ii) A switched neutral pole – a pole with contacts that are not rated for making and
breaking capacity. This pole makes early and breaks late, and therefore will not
be required to be fully rated.
iii) A rated pole – a pole which is fully rated with making and breaking capacity.