difference in electrics between UK & Ireland

Andy From Sligo

I noticed the other day that the RCD/ELCB in our consumer unit cover only the Sockets in the house - the ELCB is rated 80amps, the House was built in 2002. Now in the UK the RCD/ELCB would cover all earth leakage in the whole electrics of the house, the lighting circuit and the sockets - I just find it weird that the ELCB in our house in sligo just covers the sockets only because earth could leak to either pole in the lighting circuit just as well as in sockets. Each lighting point/switch/cieling rose has an earth wire to them, so this could mean in fact that if I broke a light switch and touched the live wire i could get a shock and without no ELCB on the lighting circuit , just a normal breaker (mcb) (5a or 10a) the electric would not cut off! - we rent this House and have has a electro mechanical and earth leakage tests as part of the landlords requirements for renting so it must have been OK not to have the lighting circuit not on the ELCB - but I just wonder why in the UK you have the ELCB protecting all the circuits in the house but the requirements in Ireland (if this is the norm ) dont wire the lighting circuit into the ELCB. And what do you reckon is best? - I would say its better to have the lighting circuit and everything wired through the ELCB.

Also why in the UK do they have 5a pull cord switches in the bathroom/toilets for the light but over here in Ireland they have normal switches but outside of the room, you could still touch them with ringing wet hands, however with a cord switch in the bathroom its much safer as well as more convenient is it not?

brightspark

I'm not sure where you got the idea that all circuits in the UK are protected by ELCBs (now referred to as RCDs). It's only since the latest 17th edition that the UK even required them on socket circuits. It is possible the the ELCB you saw in the UK protecting the whole house was a 100mA version, which is more for fire protection than to prevent electric shock. (The 30mA versions used on socket circuits now are designed to trip before fibrillation occurs at a typical value of just over 50mA)

To clarify the 16th edition only required them on sockets likely to supply equipment outdoors.

The reason for not putting everything on RCDs is that nuisance tripping would then cause a worse hazard (with the lights going out!).

Recent regulations here have added RCD protection to bathroom lighting circuits, using a separate RCBO.

Typically the risk from lighting circuits is much lower than socket circuits, you rarely touch the light fittings and the cables don't move. Whereas items plugged into sockets have exposed flexes and you often handle the appliance directly.

It is possible now that RCBOs are more common that eventually we will see new rules for all lighting circuits to be protected in some future version of the regulations.

As to the pull cord switch, it's the humidity inside the bathroom that causes the main risk, not just your wet hands. But I suppose you could extend the argument and replace all switches with pull cords, after all we often come in soaking wet from rain and turn on lights!

However I don't think I have ever got a shock from touching a light switch with wet hands.

Andy From Sligo

brightspark wrote: »

I'm not sure where you got the idea that all circuits in the UK are protected by ELCBs (now referred to as RCDs). It's only since the latest 17th edition that the UK even required them on socket circuits. It is possible the the ELCB you saw in the UK protecting the whole house was a 100mA version, which is more for fire protection than to prevent electric shock. (The 30mA versions used on socket circuits now are designed to trip before fibrillation occurs at a typical value of just over 50mA)

To clarify the 16th edition only required them on sockets likely to supply equipment outdoors.

The reason for not putting everything on RCDs is that nuisance tripping would then cause a worse hazard (with the lights going out!).

Recent regulations here have added RCD protection to bathroom lighting circuits, using a separate RCBO.

Typically the risk from lighting circuits is much lower than socket circuits, you rarely touch the light fittings and the cables don't move. Whereas items plugged into sockets have exposed flexes and you often handle the appliance directly.

It is possible now that RCBOs are more common that eventually we will see new rules for all lighting circuits to be protected in some future version of the regulations.

As to the pull cord switch, it's the humidity inside the bathroom that causes the main risk, not just your wet hands. But I suppose you could extend the argument and replace all switches with pull cords, after all we often come in soaking wet from rain and turn on lights!

However I don't think I have ever got a shock from touching a light switch with wet hands.

interesting and valid points you all made there brightspark - i never thought about all that obviously, just needed your expertise to make me sit back and think about it. Well done and thanks for taking the time to reply.

brightspark

brightspark wrote: »

However I don't think I have ever got a shock from touching a light switch with wet hands.

+1
...or fishing 16A connectors outtov pools.

The pull cord/switch is just an isolator though isn't it? Like on cookers? Never seen the need for two off switches on a device myself apart from servicing. Correct me if I'm missing something.

Andy From Sligo

Sir Liamalot wrote: »

... The pull cord/switch is just an isolator though isn't it? Like on cookers? Never seen the need for two off switches on a device myself apart from servicing. Correct me if I'm missing something.

The 5A pull cord switch i was referring to was for the light in the bathroom, but the likes of 45amp double pole pull cord switches i have seen over here do the electric showers.

maxfresh

I think the reasoning for not having lights on a rcd is not to have people left in the dark due to lights nuisance tripping
The pull cord switch is an option either switch on wall outside or pull cord inside

frankmul

Andy From Sligo wrote: »

I noticed the other day that the RCD/ELCB in our consumer unit cover only the Sockets in the house - the ELCB is rated 80amps, the House was built in 2002. Now in the UK the RCD/ELCB would cover all earth leakage in the whole electrics of the house, the lighting circuit and the sockets - I just find it weird that the ELCB in our house in sligo just covers the sockets only because earth could leak to either pole in the lighting circuit just as well as in sockets. Each lighting point/switch/cieling rose has an earth wire to them, so this could mean in fact that if I broke a light switch and touched the live wire i could get a shock and without no ELCB on the lighting circuit , just a normal breaker (mcb) (5a or 10a) the electric would not cut off! - we rent this House and have has a electro mechanical and earth leakage tests as part of the landlords requirements for renting so it must have been OK not to have the lighting circuit not on the ELCB - but I just wonder why in the UK you have the ELCB protecting all the circuits in the house but the requirements in Ireland (if this is the norm ) dont wire the lighting circuit into the ELCB. And what do you reckon is best? - I would say its better to have the lighting circuit and everything wired through the ELCB.

Also why in the UK do they have 5a pull cord switches in the bathroom/toilets for the light but over here in Ireland they have normal switches but outside of the room, you could still touch them with ringing wet hands, however with a cord switch in the bathroom its much safer as well as more convenient is it not?

Did the house in England have a TT supply? RCD protection is required on all circuit due to the nature of the supply. Most supplies in Ireland are TNCS.

Andy From Sligo

frankmul wrote: »

Did the house in England have a TT supply? RCD protection is required on all circuit due to the nature of the supply. Most supplies in Ireland are TNCS.

wow thats thrown me right out now with the TT and TNCS had to google it and come across wikipedia about the 2 systems - from that I gather that one system means the earth and neutral is connected and the other one has an earth rod in the ground by the house/pole am I correct in that? - in our house it looks like there is no earth rod around the grounds of the house so would that be a TT or TNCS system then?

Andy From Sligo

maxfresh wrote: »

I think the reasoning for not having lights on a rcd is not to have people left in the dark due to lights nuisance tripping...

Ah right I do see the logic in that, but would having lights on the RCD circuit cause that much tripping? - I mean I do know sometimes when a light bulb has blown in a fitting sometimes it trips the MCB in the consumer board, but not all the time.

Some of the lights on the lighting circuit(s) are outside lights - they would be subject to moisture and if the fitting breaks, water could leak onto terminals. It is that fact alone I would have thought sensible to have them on a RCD so the very instant of milliamps leaking to earth would trip the RCD, but would it be enough to trip the MCB? (which is rated at 10a or 15a I think on our lighting circuit in the consumer box).

tomdempsey200

afaik the UK now requires 30ma protection on all flush domestic circuits

so the new boards are dual rcd or all rcbo with 30ma protection on all circuits

Andy From Sligo

what does the O stand for in RCBO - I know the first bit would be Residual Circuit Breaker

Over-current

tomdempsey200

17th edition board

http://www.tlc-direct.co.uk/Products/WYNHISS15SL.html

DP main isolating switch
Dual rcd......all circuits rcd protected


http://www.eaton.com/EatonCom/ProductsServices/MEM/Products/ConsumerUnits/17thEditionRequirements/index.htm
rcd protection for buried and concealed cables, bathroom circuits and all sockets

Bruthal

brightspark wrote: »

It is possible the the ELCB you saw in the UK protecting the whole house was a 100mA version, which is more for fire protection than to prevent electric shock.

They can help with electrical fire prevention alright, but likely more used in houses to provide earth fault disconnection in TT systems, which would be unreliable when depending soley on an earth rod or rods, tripping an MCB, compared to an earth fault in a TN setup.

This in itself reduces the chance of a fire, but the main function is to reduce the required fault current required to operate a disconnection.

Andy From Sligo

so is a TT system the one with the earth rod or the one where the earth taps onto the Neutral on the pole/at the box? or is that a TN system?

Bruthal

TT is the earthing in the house directly connected to the earth via the earth rod. Because the transformer supplying the houses will have its neutral point earthed at the transformer location, this means there is a path through the earth rod, back the neutral. TT is for Terra Terra, (earth to earth). This path is often not of reliable low enough impedance to ensure quick operation of MCB`s, hence a main RCD.

TN has the earth bar connected to the neutral at the metering point. Our system is actualy TN-C-S. (Terra - Neutral - Combined - Separate) because before the neutralising connection outside the house, the earth and neutral path is in the one neutral conductor, but then separates after the neutralising point, coming into the house.

Neutralising ensures a low impedance path for earth faults, but it also means all metalwork connected to the earth bar can become "live" when there is an open neutral outside the house, the voltage level depending on the load on in the house, whether the neutral fault point is just for that house or a group of houses, and how good a connection the earth rod is making to earth, typically not great in most cases.

That`s where the importance of bonding comes in, so at least everything is at equal potential, which reduces shock risk.

Andy From Sligo

Bruthal wrote: »

TT is the earthing in the house directly connected to the earth via the earth rod. Because the transformer supplying the houses will have its neutral point earthed at the transformer location, this means there is a path through the earth rod, back the neutral. TT is for Terra Terra, (earth to earth). This path is often not of reliable low enough impedance to ensure quick operation of MCB`s, hence a main RCD.

TN has the earth bar connected to the neutral at the metering point. Our system is actualy TN-C-S. (Terra - Neutral - Combined - Separate) because before the neutralising connection outside the house, the earth and neutral path is in the one neutral conductor, but then separates after the neutralising point, coming into the house.

Neutralising ensures a low impedance path for earth faults, but it also means all metalwork connected to the earth bar can become "live" when there is an open neutral outside the house, the voltage level depending on the load on in the house, whether the neutral fault point is just for that house or a group of houses, and how good a connection the earth rod is making to earth, typically not great in most cases.

That`s where the importance of bonding comes in, so at least everything is at equal potential, which reduces shock risk.

Thanks for that - blimey that all sounds so technical! - I once thought about becoming an electrician once, but now after reading that I am glad I never went for it!! lol - I dont think i would ever be able to understand it all!

hufpc8w3adnk65

RCD's must now be fitted too bathroom lighting circuits lads? Or did I pick that up wrong?

Bruthal

MrMac84 wrote: »

RCD's must now be fitted too bathroom lighting circuits lads? Or did I pick that up wrong?

Yes its in a while now. A person is more likely to be injured from falling in a dark bathroom now than the practically zero risk of electric shock from non RCD protected bathroom lights.

hufpc8w3adnk65

Bruthal wrote: »

Yes its in a while now. A person is more likely to be injured from falling in a dark bathroom now than the practically zero risk of electric shock from non RCD protected bathroom lights.

I hadn't heard this. How is it proposed too be done? A seperate 30mA rcd protecting 1 10A mcb and then supplying the entire bathroom from this or put a 10a mcb on the normal socket rcd then feed the bathroom?

Bruthal

MrMac84 wrote: »

I hadn't heard this. How is it proposed too be done? A seperate 30mA rcd protecting 1 10A mcb and then supplying the entire bathroom from this or put a 10a mcb on the normal socket rcd then feed the bathroom?

10 amp rcbo would be the setup. Definitely would`t want to go near socket RCD anyway. A dedicated rcbo minimises nuisance trips anyway.

Andy From Sligo

MrMac84 wrote: »

RCD's must now be fitted too bathroom lighting circuits lads? Or did I pick that up wrong?

and so it should be, thats the way it should be - lots of moisture in the bathroom after a bath/shower

Bruthal

Andy From Sligo wrote: »

and so it should be, thats the way it should be - lots of moisture in the bathroom after a bath/shower

How many electric shocks have you received from the lights, while taking a shower?

tomdempsey200

there's very little hazard from ceiling lights

damaged striplights can be a hazard

hufpc8w3adnk65

So if you were installing a bathroom heater it would need too go on a different mcb too the 10amp rcbo. I'm assuming ceiling fans will be on this new 10amp rcbo?

tomdempsey200

MrMac84 wrote: »

So if you were installing a bathroom heater it would need too go on a different mcb too the 10amp rcbo. I'm assuming ceiling fans will be on this new 10amp rcbo?

heaters wouldn't be on the lighting circuit


ive always wired fans with the light so i put them on bathroom rcbo

tomdempsey200

i imagine we will eventually follow the UKs lead and have 30mA protection on buried and concealed cables for domestic installs

it seems inevitable

Andy From Sligo

Bruthal wrote: »

How many electric shocks have you received from the lights, while taking a shower?

not so much that but if moisture/condensation got into the fitting you'd want it to trip - I think it would trip a RCD but would it trip an MCB? I doubt it, I could be wrong though

Andy From Sligo

we have no RCBO's in our box - Just MCB's and one RCD - I suppose that was the requirements in 2002 when the house was built. We have one of those yokes in the box that only allows one 9kw shower to be used at once as well. Got 2 9Kw showers in the house but cant use both at the same time. - Have a Bell transformer in one slot. When we put on a MCB called 'range socket' (even though we havent got a range!) something buzzes/hum's like a transformer. I thought it was the bell transformer that was buzzing in the CU but its not that.

here's a pick of my consumer unit - just in case anyone is interested lol :-)

Them Bottle fuses (the one for the main fuse in the pic) look so outdated now!

2011

Andy From Sligo wrote: »

we have no RCBO's in our box

In that case do have some form of over current protection for your shower?
This is normally achieved with an MCB or fuse. RCDs unlike RCBOs do not provide over current protection.

Over current scenarios occur in ways:
1) Overload
2) Short circuit

It is very important (and a regulation) that all mains voltage cabling is protected from over current conditions.

tomdempsey200

there's a rcbo on top row of board

for some reason many were C type at the time?

maybe the B type wasn't available at the time.. I can't recall now

2011

tomdempsey200 wrote: »

there's a rcbo on top row of board

Hard to see, however it is clearly labeled "RCD" and Andy states that he has no RCBOs.

A better / closer photo would help.

Andy From Sligo

2011 wrote: »

In that case do have some form of over current protection for your shower?
This is normally achieved with an MCB or fuse. RCDs unlike RCBOs do not provide over current protection.

Over current scenarios occur in ways:
1) Overload
2) Short circuit

It is very important (and a regulation) that all mains voltage cabling is protected from over current conditions.

Ah right so my mistake. it has MCB/RCD .. so I guess that makes it a RCBO ? - is that right?

Hard to tell if the electrician who wrote on the label put 'RCD' or 'RCB'

Andy From Sligo

So the C40 on the shower RCD/MCB must mean 40amp MCB and is the ian= 0.03a means that its a 30ma trip RCD?

2011

:eek:

Andy From Sligo wrote: »

So the C40 on the shower RCD/MCB must mean 40amp MCB and is the ian= 0.03a means that its a 30ma trip RCD?

Yes.

On another note if I were you I would change out the switch fuse arrangement that you have for a modern combined unit.
I have seen the arrangement that you have go on fire :eek:

Bruthal

Andy From Sligo wrote: »

not so much that but if moisture/condensation got into the fitting you'd want it to trip - I think it would trip a RCD but would it trip an MCB? I doubt it, I could be wrong though

If any got in, its very unlikely it would end up between L & E anyway. That usually happens from water leaking into light fittings from above.

If it did trip, the bathroom would be more dangerous when dark, than the risk of shock from ceiling lights.

All circuits might eventually be required on RCBOs possibly.

Andy From Sligo

2011 wrote: »

:eek:

Yes.

On another note if I were you I would change out the switch fuse arrangement that you have for a modern combined unit.
I have seen the arrangement that you have go on fire :eek:

oh blimey! , right I will pass that onto our landlord because we rent this place - we are moving out in June, but I will tell him so he knows for the next tennants!!

Andy From Sligo

Bruthal wrote: »

If any got in, its very unlikely it would end up between L & E anyway. That usually happens from water leaking into light fittings from above.

If it did trip, the bathroom would be more dangerous when dark, than the risk of shock from ceiling lights.

All circuits might eventually be required on RCBOs possibly.

Maybe all places should be fitted out with miniature emergency light on the ceiling about the size of a smoke alarm and just run on batteries with a photo-cell in so if lights go off/trip your not in the dark...... but then again how do you turn them off when you WANT the room dark, that's the thing?

tomdempsey200

for commercial

you have to gave a backup in case the rcbo trips

last time I looked

originally domestic premises needed it but that was amended

Bruthal

Andy From Sligo wrote: »

Maybe all places should be fitted out with miniature emergency light on the ceiling about the size of a smoke alarm and just run on batteries with a photo-cell in so if lights go off/trip your not in the dark...... but then again how do you turn them off when you WANT the room dark, that's the thing?

Emergency lights have a permanent feed from the same mcb as the lights in the area that the emergency ones are fitted in. Breaker trips, or a power cut, and emergency lights come on. Reset breaker, they go off. Permanent supply keeps the batteries charged.

Only used in commercial premises though.

Tuco88

Bruthal wrote: »

Emergency lights have a permanent feed from the same mcb as the lights.

Unless you order a panel from a well known panel building company in Galway... There kind enough to use another mcb even from a different phase for your convenience for the emergency supply, Thus giving a healthy 400v at each emergency fitting. Only at the small cost of spending the day re-wiring contacters/panels that you might has well have built yourself...

tomdempsey200

Tuco88 wrote: »

Bruthal wrote: »

Emergency lights have a permanent feed from the same mcb as the lights.

Unless you order a panel from a well known panel building company in Galway... There kind enough to use another mcb even from a different phase for your convenience for the emergency supply, Thus giving a healthy 400v at each emergency fitting. Only at the small cost of spending the day re-wiring contacters/panels that you might has well have built yourself...

the ones I worked on used n/o contacts fed from each corresponding lighting mcb

EL test button opens all contacts

the person assembling the panel should have confirmed that the contacts matched up to the corresponding mcbs

2011

tomdempsey200 wrote: »

the ones I worked on used n/o contacts fed from each corresponding lighting mcb

EL test button opens all contacts

the person assembling the panel should have confirmed that the contacts matched up to the corresponding mcbs

I would expect NC contacts to be used. That way a failure of the contactor(s) or CTU to energize the contactor(s) would not result in loss of the permanent supply to any of the emergency lights.

tomdempsey200

2011 wrote: »

I would expect NC contacts to be used. That way a failure of the contactor(s) or CTU to energize the contactor(s) would not result in loss of the permanent supply to any of the emergency lights.

sorry yes
wrong way round
they're n/c.. contactors normally de-energized

Bruthal

tomdempsey200 wrote: »

Tuco88 wrote: »

the ones I worked on used n/o contacts fed from each corresponding lighting mcb

EL test button opens all contacts

the person assembling the panel should have confirmed that the contacts matched up to the corresponding mcbs

Yea contactors with NC contacts, with the contactors controlled with a 30 minute and 3 hour timer type setup, but I was not going to go into all that, just the fact about how emergency lights come on and go off during normal operation.

NC contacts for contactor de-energised normal operation, for better fail safe setup.

Andy From Sligo

2011 wrote: »

:eek:

Yes.

On another note if I were you I would change out the switch fuse arrangement that you have for a modern combined unit.
I have seen the arrangement that you have go on fire :eek:

Got into the house we are going to rent and took a pic of the fusebox and look, its the same fusebox arrangement of the house we are in at the moment. Does this mean it is a dangerous set up and can also go on fire? :-(

Also I dont think that breaker 'outside' is RCD or RCBO as well is it?, just a MCB in that unit isnt it by the looks of it, same with the shower it just looks like its a MCB not an RCBO

tomdempsey200

i have the same hager neozed fuse unit 15 yrs myself

I'm not aware of any issues( assuming fuse and connections are tight) and have no concerns

the mcb is ok but can be swooped for an rcbo

2011

Andy From Sligo wrote: »

Got into the house we are going to rent and took a pic of the fusebox and look, its the same fusebox arrangement of the house we are in at the moment. Does this mean it is a dangerous set up and can also go on fire? :-(

What you are looking at here is an isolator connected in series with a fuse.
The two are units are typically liked together with a factory piece of 10 sq. mm flexible cable. On quite a few occasions this cable has failed. Some of these devices were recalled, I can not remember which make. Either way my advice would be to replace with the more modern combined unit. This does not require the "link" cable.

Also I dont think that breaker 'outside' is RCD or RCBO as well is it?

From the photo it looks like an MCB.

2011

Here is an example of the type of failure that I described.

2011

I can't seem to find the link, but this is a quote from the ECSSA newsletter a number of years ago:

You will recall that a few years ago the Director of Consumer Affairs issued advertisement in national newspapers indicating the type of switch fuse that were banned due to being a fire hazard. It is alarming that some of these unit's are still in service.

The units concerned may be identified as follows,
EEC D02 63A AC 22B
Gould 5861.063 DO63A AC22
Lindner 5861.063 DO 63A AC22
NES UE 440V 63A
REGIS OSLF 63 1P
Hi 240V/415V-63A
Hi DO2 63A 5.5W ac 22B

Remember if you do any work in an installation that includes any of the above, even if you did not install it in the first instance you, as the professional who should have noticed it, could be held liable for any damage that might occur at later date.

SpaceTime

The big differences between the UK and Ireland on electrical systems in domestic premises are :

1) RCDs on sockets were introduced here quite a long time ago. The UK has gone from one extreme to the other no RCDs to RCDs on most circuits.

2) Ireland tends to use mostly radial circuits in most installations. The UK almost always uses rings for sockets. We don't even allow rings in kitchens anymore. So our wiring's probably a little more like modern continental European systems.

3) Ireland requires a main fuse on the distribution board - the UK doesn't.

4) Older installations in Ireland use German-style diazed or neozed cartridge fuses, the UK tended to use very primitive rewirable fuses where fuse wire's basically connected between two terminals on a porcelain thing. You had to 'mend' the fuse yourself.

Overall, I'd actually think the Irish system was a lot safer than the UK one over the years, but the UK one has now leapfrogged us by adding RCBOs to everything.

Belgium and France now also have RCDs on almost all circuits. They tend to use a split panel with multiple RCDs.