100V sockets in an Irish home. Possible? Legal?

hibby

When we were living in Ireland, we used some Japanese (100 V) appliances with appropriately-sized transformers. For some kitchen appliances, the required transformer was big, heavy, clunky, expensive and a little bit noisy.

Later this year we will go back to Ireland and we are planning to buy a house in Ireland next year. My wife wants to buy and bring home more electrical items, including power-hungry items such as an electric carpet.

Is there any possibility of having "dual-wiring" in the house, with some Japanese-standard sockets on a 100V radial, alongside the standard 230V wiring and 3-pin sockets.

I guess there are two issues - is it possible to "split" a 230 V supply into 2 115 V supplies? And would any electrician be willing to do it?

Lingua Franca

What in the name of all that is cute and fluffy is an electric carpet?

No wait, don't tell me. I prefer where my imagination is going with this one.

Bruthal

hibby wrote: »

When we were living in Ireland, we used some Japanese (100 V) appliances with appropriately-sized transformers. For some kitchen appliances, the required transformer was big, heavy, clunky, expensive and a little bit noisy.

Later this year we will go back to Ireland and we are planning to buy a house in Ireland next year. My wife wants to buy and bring home more electrical items, including power-hungry items such as an electric carpet.

Is there any possibility of having "dual-wiring" in the house, with some Japanese-standard sockets on a 100V radial, alongside the standard 230V wiring and 3-pin sockets.

I guess there are two issues - is it possible to "split" a 230 V supply into 2 115 V supplies? And would any electrician be willing to do it?

The only real way of splitting 230v into 115v is by using 2 identical items in series. Completely impractical.

You will need a transformer or transformers rated for the likely max load to do this, probably installed somewhere with sound proofing around it to eliminate the noise. Some push buttons could also be added, to disconnect the supply to the transformer when not in use maybe.

It would be a lot easier to get 230v versions of the items here probably, although I doubt des kelly has any magic carpets.

Them carpets are probably just a couple of hundred watts anyway, if they are heated mats.

Edit: In answer to the other question, it is both possible as outlined there, and legal.

Cerco

Lingua Franca wrote: »

What in the name of all that is cute and fluffy is an electric carpet?

No wait, don't tell me. I prefer where my imagination is going with this one.

I think you use them with an electric chair.

hibby

Bruthal wrote: »

You will need a transformer or transformers rated for the likely max load to do this, probably installed somewhere with sound proofing around it to eliminate the noise. Some push buttons could also be added, to disconnect the supply to the transformer when not in use maybe.

I like this suggestion. Thanks!

P_1

Lingua Franca wrote: »

What in the name of all that is cute and fluffy is an electric carpet?

No wait, don't tell me. I prefer where my imagination is going with this one.

From Wikipedia

The electric carpet is the archetypical example of device used in hazing, and has been, at least popularly, associated with American Freemasonry. It is a mat through which electric current can be run and people are forced to stand or walk on it. The torture could last hours and the volts could range from 500 to 500,000.

It can also be a warming rug.

Loving the understatement at the end

Yawlboy

My Mother in Laws house here has 110V (US) and 240V sockets throughout the Garage/workshop/office as the people who lived there before her had brought a load of stuff in from the USA. So I'd say it is possible but do you really want to rewire your house????

Mind you the electric heated self cleaning toilets I saw in Japan would be class.

Andy454

Along with the current matching of your device, you also need to be mindful of the operating frequency of your device.

Japan uses 100V at 50Hz and 60Hz depending on where you live.

I think its 110v 50Hz in Tokyo and 110V 60Hz in the west.

You need to make sure that your device will operate safely and efficiently at 50Hz if taking it to Ireland along with selecting an appropriate transformer.

I would doubt any electrician would be authorised to make such alterations to a domestic system, it may invalidate their public liability insurance and your own homeowners insurance to install a system that would be contrary to ECI rules.

The electrical safety rules require sockets to have terminal covers operated by an earthing pin.

M cebee

Andy454 wrote: »

Along with the current matching of your device, you also need to be mindful of the operating frequency of your device.

Japan uses 100V at 50Hz and 60Hz depending on where you live.

I think its 110v 50Hz in Tokyo and 110V 60Hz in the west.

You need to make sure that your device will operate safely and efficiently at 50Hz if taking it to Ireland along with selecting an appropriate transformer.

I would doubt any electrician would be authorised to make such alterations to a domestic system, it may invalidate their public liability insurance and your own homeowners insurance to install a system that would be contrary to ECI rules.

The electrical safety rules require sockets to have terminal covers operated by an earthing pin.

haven't checked- but i would assume it's allowed to fit additional sockets at a different voltage if it's done properly

cant' see why not

Andy454

Without checking, I can't see it being a runner.

Reputable electricians would be subject to public liability insurance, which probably requires them to install to IEC standards, I doubt it would cover them to install / commision ANSI fittings in an Irish domestic envoirnment.

Even so, you would have a duty of disclosure to your insurance company to disclose anything different from the ordinary 240V system and they may choose not to insure it.

If, god forbid, there was a fire, you may be also be partly / personally liable as you would be the person who ordered the installation of a 110V system which would be different to the normal standards.

You would have to source a specific distribution board, specific breakers, specific wiring (higher amperage now that your using lower voltage) a seperate earthing system etc.

You would have to implement specific spacing, ensure your earths are good, across the site as you don't want to be making up the difference if you say touch a 220V appliance and a 110V appliance at the same time. Isolation of systems can be difficult to maintain.

You would also have a duty to de-commision such a system if you were to sell or move on somewhere else...

I have been down this road myself before, before I found it simply unworkable.

I think the BS system is more developed to be honest, modern plugs prongs are insulated to prevent finger contact on insertion removal.

I got an awful shock in the states recently when I put my hand around the back of a tv to pull out the plug which was sitting half-in half-out and I touched the terminals...

You also need to consider that every BS plug has a fuse in it specific for each device to prevent electrical fire, this is not in ANSI / Japanese plugs.

It's not the same as using a specific pre-made adapter with a specific fitting than to hardwire a source to a permanently fitted installation.

You also need to consider that if someone gets a shock from an appliance in the manner above, you would be personally liable, as you choose not to implement fittings to the required safety standards, which could attract the attention of the HSA

M cebee

Andy454 wrote: »

Without checking, I can't see it being a runner.

Reputable electricians would be subject to public liability insurance, which probably requires them to install to IEC standards, I doubt it would cover them to install / commision ANSI fittings in an Irish domestic envoirnment.

Even so, you would have a duty of disclosure to your insurance company to disclose anything different from the ordinary 240V system and they may choose not to insure it.

If, god forbid, there was a fire, you may be also be partly / personally liable as you would be the person who ordered the installation of a 110V system which would be different to the normal standards.

You would have to source a specific distribution board, specific breakers, specific wiring (higher amperage now that your using lower voltage) a seperate earthing system etc.

You would have to implement specific spacing, ensure your earths are good, across the site as you don't want to be making up the difference if you say touch a 220V appliance and a 110V appliance at the same time. Isolation of systems can be difficult to maintain.

You would also have a duty to de-commision such a system if you were to sell or move on somewhere else...

I have been down this road myself before, before I found it simply unworkable.

I think the BS system is more developed to be honest, modern plugs prongs are insulated to prevent finger contact on insertion removal.

I got an awful shock in the states recently when I put my hand around the back of a tv to pull out the plug which was sitting half-in half-out and I touched the terminals...

You also need to consider that every BS plug has a fuse in it specific for each device to prevent electrical fire, this is not in ANSI / Japanese plugs.

It's not the same as using a specific pre-made adapter with a specific fitting than to hardwire a source to a permanently fitted installation.

You also need to consider that if someone gets a shock from an appliance in the manner above, you would be personally liable, as you choose not to implement fittings to the required safety standards.

dunno about all that

must take a look at et101 -see what it says

Bruthal

Andy454 wrote: »

I got an awful shock in the states recently when I put my hand around the back of a tv to pull out the plug which was sitting half-in half-out and I touched the terminals...

That`s quite an achievement, if it was 110v from pin to pin. At 110v, it would hardly be noticed unless the fingers were soaked.

Bruthal

M cebee wrote: »

dunno about all that

must take a look at et101 -see what it says

Cant see the problem myself. Supply from DB to transformer. Transformer through DP breakers for each circuit.

If thats against rules then it doesnt leave much hope for having 3 phase in a house workshop.

M cebee

Bruthal wrote: »

Cant see the problem myself. Supply from DB to transformer. Transformer through DP breakers for each circuit.

If thats against rules then it doesnt leave much hope for having 3 phase in a house workshop.

dunno if it's allowed or not-should be no problem except for frequency mismatch

-it's 100v and there's 50/60hz in japan
-there'd be proprietary sockets of some type needed

Bruthal

M cebee wrote: »

dunno if it's allowed or not-should be no problem except for frequency mismatch

-it's 100v and there's 50/60hz in japan
-there'd be proprietary sockets of some type needed

What voltage and frequency Japanese Items are would seem irrelevant really. Its more about whether a 110v transformer can be installed. It would seem strange if not, and in my opinion, silly.

cgh

you could get a 110v transformer get a circuit wired specifically of the transfomer, but to do it throughout the house would be a job in itself. then as which has been mentioned before getting it signed off is going to be hard.
you could look at getting say yellow sockets and plug tops specifically for your 110 volt equipment. thus giving them the required insulation, but best of luck getting your insurance and required paperwork to do it all.

M cebee

cgh wrote: »

you could get a 110v transformer get a circuit wired specifically of the transfomer, but to do it throughout the house would be a job in itself. then as which has been mentioned before getting it signed off is going to be hard.
you could look at getting say yellow sockets and plug tops specifically for your 110 volt equipment. thus giving them the required insulation, but best of luck getting your insurance and required paperwork to do it all.

-it's 100v, you won't be using yellow sockets or 110v trafo anyhow
-you would be buying a 100v trafo from blakely or whoever imo

M cebee

554.5.2 says sockets complying with national standards of other countries (eg:europe,usa)may be installed in commercial and residential premises

doesn't say domestic

cast_iron

What's the difference between residential and domestic?
Either way, this case is surely classed as residential.

M cebee

cast_iron wrote: »

What's the difference between residential and domestic?
Either way, this case is surely classed as residential.

it mentions nursing home as being residential ,and hotel as commercial

cast_iron

I see. I would have thought the nursing home would be in some way commercial, being accessible to certain members of the public, but that's neither here nor there.
Is there anything that states a house is not residential? Seems a strange question

M cebee

cast_iron wrote: »

I see. I would have thought the nursing home would be in some way commercial, being accessible to certain members of the public, but that's neither here nor there.
Is there anything that states a house is not residential? Seems a strange question

dunno

M cebee

Bruthal wrote: »

Cant see the problem myself. Supply from DB to transformer. Transformer through DP breakers for each circuit.

If thats against rules then it doesnt leave much hope for having 3 phase in a house workshop.

don't think you'd be using cte/dp mcbs
i'd say sp mcbs and 30ma protection
-not sure on rcd trip test and disconnection time.the regular meters wouldn't work on 100v

cast_iron

M cebee wrote: »

dunno

I thought you read it?

Bruthal

M cebee wrote: »

don't think you'd be using cte/dp mcbs

Why not?

I suppose it depends on the 100v transformers that can be got.

M cebee

cast_iron wrote: »

I thought you read it?

don't think it rules out domestic-just doesn't mention it

Cedrus

I'm don't know the regs and whether it would be ok in a domestic situation so I cannot comment on the legality in the OPs case, but I have seen lots of 110V installations in labs, factories and offices here and in the UK. I've seen a few domestic 1-2 socket installs but they were always retrofits after the electrician had finished. It has to be designed so it's impossible to mix up the sockets, but that's easy to do.

I'd say the biggest issues are practical ones, like convincing the ESB to connect, getting house insurance and getting parts when things break. If it's house wide you will be doubling (more or less) the cost of your electrical installation.

A lot of items are probably available in 230v for the Japanese expat market anyway, I'm fairly sure that Yaohan in London (when they were still open) sold 230v stuff and all the Japanese chains in Hong Kong do. Dunno about the electric carpets though:rolleyes:

2011

Cedrus wrote: »

I'm don't know the regs and whether it would be ok in a domestic situation

110V sockets?
It can be done safely and inline with the regulations (ET101:2008)

I have seen lots of 110V installations in labs, factories and offices here and in the UK.

So have I, particularly in workshops for safety reasons. 110VAC is also often used as a control voltage for MCC's and stop /stations that are wired to them.

It has to be designed so it's impossible to mix up the sockets, but that's easy to do.

Agreed and easily done.

I'd say the biggest issues are practical ones, like convincing the ESB to connect

Not a problem once it is certified and carried out by a registered electrical contractor.

getting house insurance

See above.

Cedrus

2011 wrote: »

Not a problem once it is certified and carried out by a registered electrical contractor.


See above.

I don't doubt that, once you get to talk to the right person, but I have in mind all of the battles that I've had with the jobsworths who don't want to understand that 'this one is different to what you're used to, but it's OK honestly, look someone who understands it better than you do has even signed a certificate saying it's OK'.

Been there, done that, the T-Shirt is unprintable.

hibby

Just popping back in to say thanks again - this discussion is very useful and I appreciate the people pointing out issues that I hadn't thought of, such as liability and insurance.

Based on what was said previously, I would not be looking for a separate distribution board, etc. A centrally-located 230V - 100V transformer, appropriately rated (we already have one) could supply 100V to the relevant locations (mainly the kitchen, maybe one other room).

Whether this was done with a long extension lead or by wiring to Japanese-style wall-mounted sockets would largely be a matter of neatness.

The supply to the transformer would be switched, to avoid losses when it was not in use.

The whole setup would be removed and made good when the time comes to sell the house.

2011

Cedrus wrote: »

I don't doubt that, once you get to talk to the right person, but I have in mind all of the battles that I've had with the jobsworths who don't want to understand that 'this one is different to what you're used to, but it's OK honestly, look someone who understands it better than you do has even signed a certificate saying it's OK'.

Been there, done that, the T-Shirt is unprintable.

We literally have hundreds of 110VAC sockets of the type shown below (commando type) installed in work, and are getting more installed at present.

I would not think that other types of 110VAC sockets would be permitted.

Bruthal

What`s the problem with using the 100-110v sockets that are permitted in other countries, for domestic use here?

More of our over regulation in action?

I cant see the OP wanting to plug in the magic carpet into a yellow socket.

2011

ET101 page 137, 544.5.2 is interesting.

M cebee

2011 wrote: »

ET101 page 137, 544.5.2 is interesting.

ya i referenced it earlier

mazthespark

i saw an install done before in an irish home for an american family who wanted 110v around the home for their american applliances. they used restricted duty or t bar sockets for the 110v and normal sockets and switches for the 220v. worked well. you would hardly notice the difference with the 2 sockets beside each other but one will not fit into the other. the house was inspected by reci and they had no problems with the manner it was done either.

Cedrus

2011 wrote: »

We literally have hundreds of 110VAC sockets of the type shown below (commando type) installed in work, and are getting more installed at present.

I would not think that other types of 110VAC sockets would be permitted.

mazthespark wrote: »

i saw an install done before in an irish home for an american family who wanted 110v around the home for their american applliances. they used restricted duty or t bar sockets for the 110v and normal sockets and switches for the 220v. worked well. you would hardly notice the difference with the 2 sockets beside each other but one will not fit into the other. the house was inspected by reci and they had no problems with the manner it was done either.

These are the two types that I've usually seen, the yellow ones in workshops and factories and the T-Bar in labs and instrumentation workshops. Occasionally I've seen the two pin with side earths installed.

maxamillius

We recently installed
110v sockets in the hotel I work in,every room has them now,don't see why it would be an issue installing them in domestic premises

2011

hibby wrote: »

I appreciate the people pointing out issues that I hadn't thought of, such as liability and insurance.

I can't see why this would be an issue. If an insurance company were to decide not to pay a claim on the basis of an installation having 110VAC sockets installed I think they would be required to demonstrate:

1) The installation was in breach of the regulations. I see nothing in ET101 stating that 110VAC sockets are not permitted in a domestic installation.

2) The home owner had omitted/ withheld relevant information from the insurance company. Solution: Be upfront, discuss it with the insurance company prior to taking out the policy.

M cebee

usa seems to be 120/240
japan 100
so you'd prob buy the appropriate trafo

i don't think theres any issue at all with
110v cte and the en60309 sockets anywhere as they're standard.

-100v,120v and international sockets might need clarifying for domestic use.
-domestic doesn't seem to be mentioned specifically.

Bruthal

M cebee wrote: »

usa seems to be 120/240
japan 100
so you'd prob buy the appropriate trafo

i don't think theres any issue at all with
110v cte and the en60309 sockets anywhere as they're standard.

-100v,120v and international sockets might need clarifying for domestic use.
-domestic doesn't seem to be mentioned specifically.

Just put 110v trafo in, and get 21% extra heat out of the electric carpet

Stoner

there are some 110V sockets that have the traffo built into them, they have been used in some Hilton hotels, it is the american socket connection. They are a combined unit, 220V in and each one has its own traffo (rated at i think 800Watts) They remove the need for Traffos in boards and cut out cabling, but they would be of little use for kitchens, they are really for laptops and chargers etc, I'm fairly sure you can get legrand and MK to get them so that the finishes match, once they have a sticker on them indicating the limitations on the load (rating and voltage) then I don't see an issue with them, they have the US socket connections and they are a combined unit, really a recessed 220/110 unit with an american socket.

Solair

There are significant differences between the Japanese and North American systems so be careful as some sensitive Japanese equipment can be damaged if used on North American voltages (120V 60Hz these days)

Japan uses 100V 50Hz in Western Japan or 60Hz in Eastern Japan.
So, appliances are 50/60Hz.

Be careful to check what voltage the transformer you are using actually outputs. You might need to actually test it.

Irish / UK site transformers provide about 110V 50Hz across the live and neutral pins. However, they're about 55V to earth (both pins are live). This is so that if someone cuts a wire, they only ever get exposed to about 55V.

Your Japanese stuff might be happy enough supplied by one of these and they are easily available in Ireland and provide over-current / shock protection.


That makes life a lot easier for using Japanese appliances in Europe as they'll be quite happy on 50Hz, where as North American appliances (especially with synchronous motors etc) can behave rather oddly.

The challenges as I would see them:

1) 100V sockets wouldn't be exempt from RCD protection, so you'd have to provide it and I am not sure where you would buy a 100V RCD in Ireland. Maybe you could import one from Japan, but then it wouldn't be CE approved / recognised here..

2) same problem with MCBs.

3) Your wiring would need to be calculated correctly to deal with 100V. Because the voltage is quite low, you would probably need a radial 15amp circuit for every socket almost. 15AX100V = 1500W...
I am not sure if you'd be allowed to rate the circuits higher than the max rating of the socket outlets or not.

4) Plugs/Sockets would need to conform with CE standards. NEMA sockets/plugs don't as the pins are accessible as you're inserting them. So, you'd probably have to use CEEform industrial plugs to comply with the regulations here.

I suppose, you could perhaps use some other CE compliant connector with keyed pins. Using a 230V plug like BS1363 or Schuko would be dangerous if the appliance were ever connected to the wrong voltage.

To be perfectly honest, local transformers would probably be easier.
You're getting into all sorts of regulatory messes when you start using foreign voltages and non-European equipment. The wiring regulations are quite strict and specific, so you can't really interpret them very much. Even if something would work, it doesn't necessarily mean it's permitted so an electrician cannot sign off on it.

I would just buy some power-strip extension leads in Japan and connect them to CEEform yellow plugs and use them with a site transformer if I were you.

A site transformer will generally have a very good quality transformer in it, capable of dealing with power tools and other high loads. They usually have over-current protection and will trip out if overloaded too and they're also very robust and well built.

The transformer inside is designed to take in UK 230-240V and output 110V 50Hz, so I would suspect when used in Ireland it will be on the low side of 110V so, Japanese gear might be happier.

A lot of UK/EU to USA/Canada transformers are pretty crude 2:1 conversions. So, they'll output 115 - 120V which is the US spec.

Inidentally, you can buy NEMA-style sockets rated for 127V use (which I think is in the Caribbean and UAE) that fit Irish/British wall boxes and are shuttered.

http://www.fastlec.co.uk/15a-127v-flush-2g-shuttered-non-uk-socket-k2252-whi-p-10872.html#.UQLos6trmvQ

Bruthal

Solair wrote: »

The challenges as I would see them:

1) 100V sockets wouldn't be exempt from RCD protection, so you'd have to provide it and I am not sure where you would buy a 100V RCD in Ireland. Maybe you could import one from Japan, but then it wouldn't be CE approved / recognised here..

The RCD will work regardless of voltage. The test button would be the only possible problem, as well as testing them with test gear. If cte was used, no RCD needed.

2) same problem with MCBs.

They should also work, an amp is an amp.

3) Your wiring would need to be calculated correctly to deal with 100V. Because the voltage is quite low, you would probably need a radial 15amp circuit for every socket almost. 15AX100V = 1500W...
I am not sure if you'd be allowed to rate the circuits higher than the max rating of the socket outlets or not.

Probably 2 or 3 sockets per 20 amp circuit alright. They probably wouldnt need to many anyway.

4) Plugs/Sockets would need to conform with CE standards. NEMA sockets/plugs don't as the pins are accessible as you're inserting them. So, you'd probably have to use CEEform industrial plugs to comply with the regulations here.

Maybe T bar sockets could be used.

I suppose, you could perhaps use some other CE compliant connector with keyed pins. Using a 230V plug like BS1363 or Schuko would be dangerous if the appliance were ever connected to the wrong voltage.

To be perfectly honest, local transformers would probably be easier.
You're getting into all sorts of regulatory messes when you start using foreign voltages and non-European equipment. The wiring regulations are quite strict and specific, so you can't really interpret them very much. Even if something would work, it doesn't necessarily mean it's permitted so an electrician cannot sign off on it.

I would just buy some power-strip extension leads in Japan and connect them to CEEform yellow plugs and use them with a site transformer if I were you.

A site transformer will generally have a very good quality transformer in it, capable of dealing with power tools and other high loads. They usually have over-current protection and will trip out if overloaded too and they're also very robust and well built.

The transformer inside is designed to take in UK 230-240V and output 110V 50Hz, so I would suspect when used in Ireland it will be on the low side of 110V so, Japanese gear might be happier.

A lot of UK/EU to USA/Canada transformers are pretty crude 2:1 conversions. So, they'll output 115 - 120V which is the US spec.

Inidentally, you can buy NEMA-style sockets rated for 127V use (which I think is in the Caribbean and UAE) that fit Irish/British wall boxes and are shuttered.

http://www.fastlec.co.uk/15a-127v-flush-2g-shuttered-non-uk-socket-k2252-whi-p-10872.html#.UQLos6trmvQ

I think this thread is making it seem like rocket science. Again id say, over regulation seems the order of the day if a few 100v outlets cant be wired in a house.

Solair

You'd be amazed. The regulations are pretty prescriptive in most countries.

Under-regulation tends to give you the random combinations of all sorts of national standards that you find in some developing nations.
There are countries around, like Switzerland, that won't even let you wire your own plug. The US' wiring is pretty seriously tightly regulated in most states too.
The issues here is that an electrician may not be able to sign off on a non-standard installation that doesn't comply with ET 101.
If someone does DIY work it's a different story. However, I am not sure where it lands you with things like house insurance.

M cebee

it's tricky alright
100v trafo
sockets
disconnection time and rcd trip time for signing off

mcb and rcd voltage rating

mostly red tape really!


as robbie said the mcbs and rcds will operate at 100v .but the rcd voltage rating needs to be 100v anyhow for test button operation


hager rcds are all rated for 110v operation and i think some other manufacturers

i'm not clear on mcb operating voltage-is that a maximum working voltage?

Solair

To paraphrase Garret Fitzgerald:

It may all work in practice, but will it work in theory?

In general electrical regulations are a bunch of tight rules with no wiggle-room. The problem really is just red tape with all of these things, but they're designed to be idiot-proof and really to take the guess work out of it.

The aim is to have a safe, standardised system that has no major requirement for endless calculations and testing.

Because there's a risk of shock/fire, they're not flexible and anything unusual will tend to fall outside the regs.

On the RCD:

If it's supplied by a centre tapped site transformer, the max shock voltage to ground would only be about 55V anyway. Would that even require an RCD? It doesn't for site tools.

Cedrus

Solair wrote: »

It may all work in practice, but will it work in theory?

I like this, this I like!

I needed to use this quote in a site meeting this week.

Bruthal

M cebee wrote: »

i'm not clear on mcb operating voltage-is that a maximum working voltage?

When a switch or breaker is carrying current, it is just current, so a 20 amp breaker carrying 20 amps supplying 100v or 230v, will be operating the exact same.

But when it interrupts the current, the voltage appearing across the contacts will have an upper rating that the breaker can interrupt.

The breaker is interrupting the actual load, at 100v 20 amps, its 2kw, at 230v its 4.6kw

Bruthal

Solair wrote: »

In general electrical regulations are a bunch of tight rules with no wiggle-room. The problem really is just red tape with all of these things, but they're designed to be idiot-proof and really to take the guess work out of it.

The day electrical work becomes idiot proof due to rules, is the day I will like doing it.

The aim is to have a safe, standardised system that has no major requirement for endless calculations and testing.

100v or 110v is hardly unheard of. Its just unusual in a house. That does not mean its unusual. Imo, if it cant be done due to rules, then we cant call electrical work a craft.

Because there's a risk of shock/fire, they're not flexible and anything unusual will tend to fall outside the regs.

Far less risk of shock with 110v. Even contact with the full 110v is very unlikely to yield even a half decent shock. Add cte and 55v cant really/easily be perceived unless its in the gob or close. I actually think its probably unlikely to trip an RCD even with the full 110v in contact hand to hand.

On the RCD:

If it's supplied by a centre tapped site transformer, the max shock voltage to ground would only be about 55V anyway. Would that even require an RCD? It doesn't for site tools.

No RCD required for that. It could be isolated secondary side which wouldnt need one either. The problem then is there is no monitoring of the 110 side, and one pole having an earth fault, and now the other has 110 PD to earth.

A cte with RCD would be useful for reducing fire risk, but that risk is there in all circuits.

Solair

hibby wrote: »

I guess there are two issues - is it possible to "split" a 230 V supply into 2 115 V supplies? And would any electrician be willing to do it?

Eh, just to refer back to your original post. You can't actually 'split' a European 230V 50Hz power supply as it's just a 230V live and 0V neutral.

.........

In the USA, Canada and probably Japan, they use a 3-wire 'split phase' system.
This means you have a connection to a centre tapped transformer out on a pole / underground. Three wires enter your house Live 1 (115V) Live 2 (115V) and Neutral (0V).

If you connect something between the two lives, you get potential difference of 230V. The lives are 'out of phase' with each other so the potential difference is always 230V.

If you connect from either live to neutral / ground you will get 115V.

.......

In Europe this system was used in some places in the very early days of electrical power. 220V + 127V was quite common in some places before WWII but it's now obsolete and has long since been phased out of use.

The reason's pretty simple:

The North American style system requires a lot more wiring, and local transformers serving every few homes.
You typically have a local distribution system operating at at least 3000V and pole mounted can transformers or underground transformers step that down to 230/115V. Each home needs to connect to the centre point of the transformer so it has to be quite local.

Also, it makes it difficult to supply enough power to large appliances e.g. kettles, irons, etc (limited to about 1500-1700Watts in the USA vs comfortably 3000Watts in Europe).

The safety advantage of 115V over 230V is also very negligible. They will both kill you stone dead if you happen to be unlucky enough to get a current flowing across your chest. RCDs are required in both areas these days and prevent lethal shocks. It's a relatively unusual cause of death in Ireland or most of Northern / Western Europe / Australia NZ etc.. Most people killed by electric shock tend to come into contact with high voltage lines / construction site accidents etc. Rare enough to be badly shocked at home.

In Europe, in most areas (other than very rural places where pole-mounted transformers are also used) we use pretty large local transformers serving a whole area (substation).

That substation sends out three phase power. So, you've three lives at 230V and a neutral at 0V.

Each home in the area can then take one of those lives + the neutral or all three lives and the neutral if they want three-phase power (more common on the continent).

The aim is to distribute the load across all three phases. So, in Ireland you just alternate it so every third home is on a different phase. In Germany they tend to give you all three phases and you split your loads in the house across the three phases. There are arguments for/against both ways of doing it.

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Just posting that to give you a bit of background as to why you can't 'split' the supply.

In short, the only way to get 115V in Europe is to use your own transformer. There is no source of anything lower than 230V from the power company's incoming supply.

Bruthal

Solair wrote: »

The safety advantage of 115V over 230V is also very negligible. They will both kill you stone dead if you happen to be unlucky enough to get a current flowing across your chest.

I wouldnt agree with that. 110v would be very hard to get electrocuted with. 230v is far more dangerous. Contact hand to hand with 110v wire sized contact points is perceivable. But not a lot more than just fairly perceivable. The same with 230v is far more severe. There is a major jump in shock level from 110v to 230v when the contact is hand to hand. To get a good shock from 110v would want exceptionally good contact.

And its not through assumption that im posting that, where as many people talking about 110v shocks are making assumptions that it is half of 230, so will give a good shock for the same level of contact.

Look at 55v as well, not really perceivable, yet its 1/4 of 230v which can deliver very dangerous shocks with 2 hand contact. Its probably 4 times the shock level for a double of voltage.