Hi again!

I learn that in the UK 400V is considered too much for "common people" and therefore you are sockets in proximity of each other must be on the same phase, houses are single phase only and so on.

The US seem to have a similar attitude. This contrasts starkly with the view in some European countries where even the cheapest choco bloc is marked 400V and 3-phase used as much a possible. (In Sweden lot's of stuff, like washing machines, tumble dryers, dishwashers, kettles, irons etc. draw 2200W... Switzerland is a another good example. Sockets have a 10A rating and therefore 400V is used for loads exceeding 2200 KW.)

On our sockets there are even two "blind" terminals on the 230V sockets, allowing you to use the 230V sockets as a choco block for all 3-phases. (It's allowed in offices but not in homes, since a homeowner is bound to wire it wrongly if he/she replaces the socket.)

Any pros and cons from you on using 400V in domestic environments? Is it a must or a horror?

Hre in Austria 400V (or 380 as everyone says, sorry if I get this mixed up) is used for every bigger appliance. Most common example are electric ranges, but you can find larger woodworking tools, washing machines, garden appliances, concrete/plaster mixers (pretty common for DIY use), air compressors, pressure washers, ceramic heaters,...
Almost evrything is available in a 380V version, and everyone who lives in a single-family building has several 3ph outlets installed around the house.
220 and 380V wiring MUST not be in the same conduit and junction boxes after leaving the panel. As a result of this it's also illegal to tap off a single ph run from a 3ph one. So the Schuko receptacles C-H mentioned would be a violation.
Almost everything (choc blocks, voltage testers, electric tape, fuses,...) is rated 500V.

Yes, the British IEE usually considers 250V to be something of a cut-off point above which extra precautions need to be taken. (250V being the highest nominal voltage in the days when different districts could have slightly different supply voltages).

There is nothing to stop a very large house having a 3-phase supply, but it's very rare. If 3-phase is supplied, then all sockets in any one room must be on the same phase, the idea being to eliminate the chance of two appliances within arms reach of each other having ~400V between them.

Even in commercial environments there are requirements for labeling of the highest voltage present between adjacent equipment if that voltage exceeds 250V.

Whereas in Continental Europe most of you can have residential 3-phase service at maybe only 20A per phase, in the U.K. we prefer 1-phase at 100A or so for residential.

Does anyone have any views for or against either approach?

Hey guys, thought I would jump in and give some American perspective.

3-phase is totally unheard of in residential settings on this side of the pond. The highest voltage encountered here in a house is 240 volts phase to phase, for major apliances like a range, dryer, and air conditioner, as well as in multiwire circuits.

The parallel I can draw to your 415Y/240 system in a house would be our 480Y/277 system here. To have that in a house would be completely nuts, IMHO!! Just check out the Violation photos to see the hack work done on residential single phase systems. I can just imagine some of the DIY nightmares that would be created with 480 3-ph in a residence. Not to mention the danger.

By the way, the NEC requires dividers in the switch box between adjacent 277 volt switches that are on different phases.

Hi Peter,

Haven't heard from you in a while!

We also use phase barriers in some cases where two or more phases are present in the same box.

It is interesting that North America considers that nothing should exceed 120V to ground/240V between lines in residential whereas in Europe it's considered quite acceptable to bring 220/380 3-phase into a single appliance.

The U.K. position is somewhat in between, but believe me I sometimes flinch at the wiring I see here which is at 240V to ground.

As a matter of fact, 380V work usually isn't as botched as 220V. I've seen tons of really scary 220V stuff, but the worst 380 thing I've seen was a brittle appliance cord. As long as you don't coun't an untidy panel as really scary.

Here we follow the continental view. We therefore can get 230/400V residential installations by special demand. All residential appliances, however run on 230V. The exception being ranges which can also be wired as 400V.

[This message has been edited by Belgian (edited 10-29-2002).]

Hi Paul. I tried, but I couldn't stay away! Anyway, this international discussion has been really interesting.

Furthering what I said above, 3 phase breakers and 600-volt rated equipment, like meter sockets and panels, is considerably more expensive than our typical "residential grade" stuff. Of course, that is assuming that one could even install it in a residence (which you can't)!

Hmmm....3 phase in a house.....I wouldn't mind that so much in my house! I can just imagine what the workshop would look like!

Why is that? You won't find a single-phase main switch here. Also, there is no such thing as 3-phase panels, as the panel is completly passive. (It's just a plastic box)
A 3-phase breaker carries about the same price as a single-phase breaker.

Here you sometimes see "over-rated" switches: E.g. the switch for the washing-machine in my house is marked 400/690V rather than 230/400V. Some electric motors sold at the sheds are also marked 400/690V. Does anybody know where this system is used?

So you might like the idea of moving to Continental Europe then.....

C-H,
So would I be right in assuming that all your panels are hardwired from main to each breaker? We could do that here, but most general-purpose units come fitted with a busbar for the MCBs. Hardwiring is generally restricted to small sub-panels, such as a two-way unit in a garage or workshop. Even then, it's only found on the newer DIN-rail style units.

Ehh? Now you've lost me! Are you refering to wiring each breaker with wire as opposed to using a busbar? Here, insulated 3-phase busbars are the norm. I was surprised to see your uninsulated single-phase bar in the "Who needs circuit breakers anyway"-thread. They come in different types: "fork", which you seem to be using, and "pin" which has - surprise! - "pins" instead of "forks". (Different brands, different MCB:s) But it's not part of the panel itself. It's something you put in the box, just like the MCB:s and RCD:s.

I'm a bit lost here since I'm not electrician, and try to keep out of panels as I will probably do more harm than good. Unless I'm sure that I'm doing things right, I call a professional. (It's both safer and legal)



[This message has been edited by C-H (edited 10-27-2002).]

Before Din-rails were invented all our panels were custom-made. They were usually surface-mount or steel boxes without a back and threads to mount rails on. There were metal (now plastic) rails the Diazed elemnts and other stuff were mounted, and with a surface-mount assembly you could cut these rails just as long as you wanted to. They're stiil on sale, because metal ones have to be replaced when any work is done. The diazed elements were linked with flat brass straps with holes that fit under the screws of the element.
Din-rail panels are a plastic box with one or more rails, neutral and ground bus bar in it. (Neutral commonly unused, as 2 pole breakers are used) Insulated fork bus bars are available, but the norm are short wire links from load side of main GFI (on the rail as well) and the breakers.
4 pole GFIs cost 4 euro less than 2 pole ones (no joke). Each and every service here is 3ph, just sometimes 2 of the phases are terminated at the main fuses or all 3 taken to the meter.

C-H,
The primary reason is that 3 phase equipment is typically better quality (re: more rugged, built with higher AIC raitings, etc) than residential grade eqpt. Though in recent years, our commercial/industrial stuff has been arriving from Mexico, Puerto Rico, etc and the quality has suffered.

A lot of residential stuff is now sold though mass merchandisers like Home Depot and Lowes, which have pushed the prices (and quality) down even further.

A few examples:
Square D "Homeline" 20 amp SP breaker $3.50
Square D 277 volt 20 amp SP breaker $57.00

These are wholesale prices off the top of my head.

I can dig up my catalogs to find out more if you like.

Paul,
Or I can just convince the poco to run a few more high voltage legs and transformers down my street! I'm sure they will....

$3.50 is what you pay here for the Chinese breakers. Don't know anything about the quality and I'm not sure I want to know...

$6 for a single pole, $11 for double pole austrian made F&G breaker (only type they sell at Baumax), $42 for a 4pole main GFI, $45 for double pole (same manufacturer).
These are known as high quality stuff (ours have lasted for 25 years now and still work perfectly, some newer, cheaper ones failed after 2 years, wouldn't properly reset, just because it has been turned on and off manually a few times.)

That $3.50 breaker is assembled in Mexico.

<threadjack>
I avoid any electrical product "Made in China" like the plauge. Chinese made crap seems to be flooding the market these days, and I don't like it a bit. In fact, I just threw away a bag of Chinese made wirenuts that were knockoffs of our Ideal brand that I got for free to try out.
Well, they were junk and nowhere near as good as Ideal.

What did you expect?

But, in all fairness, I have to admit that the Chinese-made extension cords I've seen were just as good as the European ones, with shutters and all.

>But, in all fairness, I have to admit that the Chinese-made extension cords I've seen were just as good as the European ones, with shutters and all.
The only difference is that the chinese sutters break or get blocked after inserting 3 times a plug in it. I've seen a huge difference in quality.

I just noticed what Belgian wrote:

>The exception being rangers which can also be wired as 400V.

You better look out Ranger, or Belgian will wire you to 400V!

Help! And I don't even like being wired up to 230! Think I gotta watch out if I ever meet him! Or at least hope this meeting takes place in a 120V country, or even Japan.

I just saw a 25m extension cord made in Romania (10 Euro). It's pretty nice stuff (very flexible rubber-like sheathing, unbreakable cord caps), but the ratings are a bit strange. The tag shows 1 mm2 wires (which seems to be true) and a max. current of 16A.
Hmmmm.

>The tag shows 1 mm2 wires (which seems to be true) and a max. current of 16A.

Ahh! There is nothing wrong with the rating. It just doesn't mention that it's valid only when the cord is submerged in water.

Seriously: A 1.0 mm2 cord is good for 13A under ideal conditions. In many cases, 6A is closer to the truth.

Personally, I would not like to have 400V
inside a house over here.
For one thing, there is no need for voltages like this, in the largest appliance(the Range), this would only be spread over two Phases + Neutral, this is still only 230V, but this is only in rural areas where the voltage regulation is poor.
With the advent of a lot of dairying out in the rural areas, we find ourselves using 3 Phases+ Neutral, because of the submersible pump, normally using 3 Phase, this is the only 3 Phase load, but the rest of the installation is balanced over the 3 Phases.

I have 400 volts here at home - never use it. it was put in a long time ago for a spa pool. I am currently doing a lot of alterations at home so may well utilise it.
Like Trumpy said Normally its rural or a BIG house.
CW

Better watch it Ranger! Looks like he's getting ready for you....


Trumpy,
But even though each heating element may be only 230V, there is still 400V in the range between phases.

Each 13A outlet here is only 240V, but the Regs. specify that all sockets in the same room should be on the same phase to avoid having 415V between them.

Ouch! Think I should stay clear of him!
Situation seems to get tense!

In a recent US teevee broadcast of "The Green Mile" the officers placed separate electrodes on each leg of the inmate plus the skull cap. Also, the "switch" was a beefy multibladed live-front 3-pole version--maybe 400-600 amperes.

The movie proved that the human body is highly capacitive. When anyone was "paralleled," the lites in the prison consistanty got brighter and, naturally, some exploded from obvious overvoltage.

Read it again. It doesn't say Rangers but ranges. By the way the death peanalty is not practiced in Belgium as in the USA. Texas Ranger, you don't have to worry, unless, of course we meet in the USA!

Ok, not much danger. I don't think I'll get to the US the next years
typos can always happen..

Paul, thanks for that, I do realise that it is still 400V.
Voltages like 400V, are pretty tame, compared to some of the voltages that I work with, admittedly the short-circuit arc,is normally not experienced in a domestic situation, but I can vouch for a number of
serious line accidents.

It just illustrates some of the problems that would need to be argued out if we were to get a common European wiring code. On the Continent, 3-phase ranges are accepted in residential applications, but in the U.K. many people reel in horror at the thought of somebody having 400V in a kitchen appliance.

Makes a change from all the movies where the lights dim so much that you wonder just how small the main service cable is!

All of the free-standing stoves (ranges) that I connected up in South Africa can be supplied with 3 phase and their live terminals are marked L1, L2, L3. A busbar connects all three and is wired to the single (40-50A) phase that I have only ever seen supplied in a RSA house. The 3 phase split is used purely to balance the load although a higher phase to phase voltage would be present within the stove in these circumstances.

Interestingly, the wiring method for a free-standing differs from Province to Province as in the old Transvaal (now Gauteng, Mpumalanga, Northern and parts of Northwest) a house had, by Regulation, to be sold or rented with a stove installed. In these areas, all stoves are hard-wired to flexible conduit sheathed cables that emerge near the floor, behind the stove and under the double-pole isolator switch. Elsewhere in the country, a house comes without a stove, and in Natal where I once lived, there was a special 40A - 230V socket in the stove space. This socket was a strange round, white metal beast that protruded from the wall and faced downwards at 45 degrees and was threaded on its outer ring. It accepted a similar plug with short stubby L,N,E pins and an outer captive ring that screwed onto the socket once the pins were inserted. This plug was connected to 6sq mm cables in flexible conduit which led to the stove.

This was my first serious wiring job as a stove was never sold in Natal with the necessary cable, conduit and plug!

Don't like the idea of 415V for standard residential installations.
I have seen it occasionally, in really big houses or where there is electric storage heating with a load over 20Kw.

A lot of houses in the older parts of Inverness (pre 1930's) have a 2 phase & neutral supply. I am told this stems from the days when the supply was DC 3 wire. When conversion to 240/415V ac was carried out the existing paper/lead underground cables were re-used & many of these cables are still in service. Only 1 phase & neutral are normally taken from the service fuse to the meter, the other phase is left un-used.

Most imported stoves here also have 3 phase connections with copper links between the phases for 240V 1 ph use. I expect it enables the manufacturers to sell the same model in all EU countries & beyond.

David,

Seeing you’re a Scottish electrician, I wonder if you could answer a Scottish inquiry. My brother-in-law’s house in Glenfarg, Perthshire has an immersion heater in a closet off the landing which uses an old round-pin 15A plug as a disconnect. The house must be around 1970’s vintage. Is this normal as the set-ups I’ve known in England and South Africa are hard-wired into a double-pole isolator?

What struck me as unusual in this case was that South African immersion heaters that I am familiar with are on dedicated 30A circuits which would exceed the capacity of this connector. PaulUK said that standard UK heaters pulled about 13A. Sorry for being so far off-topic!

Interesting on the 2-phase services in Inverness. It begs another question though: Why were these houses fed with all 3 lines of the old DC service instead of the usual 2-wire tapped from 3-wire?

Are we talkng about really big homes here, which would have had very heavy loads by 1930s standards? Or was this a localized example of a 120/240 (or thereabouts) DC system instead of the usual ~240/480V?

>Stoves have the L1, L2, L3 terminals linked together.
How does that work? I learnt that electric ranges work on a 400V delta, each element fed by 2 phases.

Just remembered this one: You might like to compare the DC to 2-ph AC Inverness conversion with Ranger's post about a DC to 3-ph AC conversion in Vienna. Go here.

TR,
With the way many appliances are now sold in the same model across Europe, I've seen plenty of ranges wired for 3-phase here as well which are starpped L1-L2-L3 for use on our 1-ph residential services.

The elements are still regular 230V types, but wired on different phases to distribute the load.

Are you by any chance thinking of American 240V range elements which would be wired across the two 120V hots?

I was jsut quoting my physics teacher. I never actually checked that (we have a gas range at home, way cheaper and more effective).
Must be that way then.
I've once seen an electric range connected via simple red-grey CEE plug and receptacle at acountry fair.
Was a nice thing. They tapped off the OH service of the nearest house and ran OH cable over some trees to the big tent. One support was a long board they bound to the lavatory trailer with some insulated copper wire. They drove 2 drywall screws into the top of the board facing upwards, laid the cable between and fastened it with some wire. From the main panel they ran literally kilometers of extension cord. (Was a tent for several thousand people). I saw that work while doing some minor helper-jobs (mostly standing around and cheering up people)

On the Wye versus Delta thing on stoves:

Traditionally, our ranges have 400V rings. Thus, the range has four wires: L,L,L,PE and is hard wired. (You can also wire it L,L,PE and thus run it on 400V single-phase.)

Some new ranges are fitted with five pin (Perixlex) 3-ph plugs with a neutral. I think they are wye and can be wired to 230V too. (I should know this!) I forsee problems for many homeowners, as there are only four (1.5 mm2) wires coming out of the wall...

Today 400V only ranges have a Perilex plug where the neutral pin has been left out.

Thanks C-H, that's what I thought. All our ranges (except for the one mentioned) are hardwired to a 16A (2.5 mm2) 3ph supply.

>All our ranges (except for the one mentioned)
>are hardwired to a 16A (2.5 mm2) 3ph supply.

Why hardwire them when there are 16A Perilex plugs?

[This message has been edited by C-H (edited 11-03-2002).]

Dunno. Maybe Tradition. Most bigger aplliances are hard-wired here. (space heaters, ranges,...)

Hutch,

Re Brother-in-law's immersion heater.
UK domestic immersion heaters do not normally exceed 3Kw @ 240V (12.5A).
It is considered bad practice to use a 13A socket or connection unit for the final connection to an imm. as it may overheat due to the high continuous load & ambient temp. in the airing cupboard.
I have seen the 15A plug & socket used as the final connection to imm. htrs. in many homes built in the 60's & 70's.
I should point out that it is only installed as a local isolator for anyone working at the imm. or hot water cylinder. A control switch (20A DP & neon labelled water heater) is installed in a convenient position, usually the kitchen for normal control of the imm. by the householder. This is another minor difference in practice from England, where I understand (correct me if I'm wrong Paul) they do not install a control switch in the kitchen.
Nowadays we use a 20A DP switch as the final connection for imm htrs, with a control switch in the kitchen.
Hope this answers the question.

Paul,
Yes these are large houses with a 3 wire service.
I am told that in the days of DC the voltage was around 120V, but I really don't know much about it. I think conversion to 240/415V AC was around 60 years ago.

[This message has been edited by David UK (edited 11-03-2002).]

C-H,
Re the 400V range elements, it just goes to show how accepted practice differs from one country to another. What about some of the ancillary apparatus found in a modern range? Do your appliances use 400V timers, clocks, lights, fan motors, and so on? Or is a 400V-230V transformer fitted inside for these?

David,
I've seen both BS1363 (fused 13A) and the old BS546 15A plug/socket combination used as an immersion disconnect in properties wired in the 1950s/1960s as well. (I once had someone who was convinced he could buy the "special 15A fuses" for 13A plugs for just this use!) Unfortunately, I see a lot of DIY immersion wiring where somebody has run 2.5 T&E straight into the heater instead of going to heat-resistant flex for the final loop.

Thinking about the location of the switch for the water heater, there doesn't seem to be much consensus in England on where it's placed. Some houses have it in the kitchen, but the hallway is another favorite. Inside the airing cupboard itself is also very common, usually then using a combined switch/flex outlet.

It would be interesting to find out just how long some of the 120/240V DC services survived. I'd always thought that this utilization voltage was very much confined to the very early days of home electricity in Britain and that they were soon converted to 240/480V. It sounds as though some lower voltage systems survived for much longer.


[This message has been edited by pauluk (edited 11-04-2002).]

Good question! Unfortunately, I cannot answer it. I go since I've sold cookers and fridges...

The only feature on a standard range is a lamp inside. I suppose a 230V bulb can be run on 400V using a diode. The high-end ranges with all those extras have a neutral. Therefore, I find it likely that the features are powered by 230V.

I have written to Electrolux to find out for sure.

[This message has been edited by C-H (edited 11-04-2002).]

As all the ranges I know have a neutral as well I suppose all the auxiliary stuff runs on 230V.
Maybe also a 230V lamp hooked up with a resistor, but I don't think so. The cable emerging our ranges (flex) are always 5 wire (Don't know about 1950ies and so stuff), 3 phases, neutral and ground, wired into a box with special cover with 5 strip connectors and strain relief. (It's a metal frame with the electrical stuff mounted on that's put into the box, and then a blank cover with a hole for the cord goes on)

I doubt they'd use a series diode. A 230V bulb connected to 400V through a diode would still be severely overrun and probably wouldn't lasy very long.

Be interesting to hear the response from the manufacturer, but by bet is on a small transformer.

Is Electrolux a popular make in Sweden? Their base in the U.K. is near to where I grew up; they're most closely associated with refrigerators here.

I did get a response from Electrolux. It was unintelligble. Anyone who is surprised?

Electrolux is pretty much the only manufacturer selling ranges, fridges and the like in Sweden. They have >90% of the market, but use different brands to make it less obvious. AEG, Husqvarna, Electrolux and a number of other brands.

C-H,
A range with no Neutral, even though it has
3 Phases feeding it, pure 400V.
It just makes any short-circuit fault, all that much larger!.

I think we may have a glitch in the software, as there was a post here with a null message, no user ID field, and a completely scrambled date. I've deleted it to get the thread back where it belongs.

If somebody did indeed try to post to this thread recently, then please try again.

bonsoir paul: yeah that the link i am looking for anyway one of you guys metion about north american stove burner rings almost all north amercaian stove are wired straght 240 volts ( but have handfull rated for 208 volts ) but do have nuturel line there also for 120 v lightbulb and timer etc.. but i will cut to chase somewhere on the forms i dont remember where it was but it did mention about dryer on 240 volts too if someone can find the link please do that for me unforetealy most N.A. stove are wired single phase using 40 or 50 amp lines typically about 9.5 kw to 12 kw or so depend on what it have it


merci marc


(p.s. paul i did try to find this forms and many thanks to find it )

From what i've seen of French cookers/stoves sold here they're wirable for either 230V or 400V. I think the way they actually work is to split the elements over different phases they're actually 230V but different parts of the cooker will be supplied by different phases sharing out the load.

Our hob for example came with a full 5-wire lead on it and if you're connecting it in Ireland to 220/230V you simply connect all of the lives together using a specially supplied junction box (3 X lives on a bus bar) to a single 220V live. So at the very most all it's doing is shifting each plate/group of plates to different phases.

Yes, now that we have many models being sold in the same form right across Europe, I've seen many such ranges arranged in this way. All the individual elements are 230V wired phase to neutral, but distributed between the 3 phases.

When we use them in a British domestic kitchen we just strap the L1, L2, L3 terminals together.

I've also seen quite a few older U.K. made ranges (say early 1970s) which were wired internally to a single pair of L1 and N terminals, but the terminal block had empty positions clearly labeled L2 and L3, which must have been used for export versions.

If you have ever cut a 3phase+Earth cable that was supposed to be dead, and had your cable-cutters wrecked by the flashover,
my case in point.

I really can't see the advantage of 3-phase in anything other than industrial situations where the smooth starting and running of large-scale electric motors is a concern. 230V single phase supplies quite obviously can and do work perfectly effectively and safely in UK/Ireland for everything including heating and cooking. 380/400/415 volt 3phase systems just add extra shock hazzards and excessively complicated wiring for no good reason.

In heavy load domestic situations here where electric space heating is used a second 80 - 100amp supply (not necessarily from a different phase) is sometimes added specifically for that purpose. The heating system would be metered seperately, fused seperately and treated as a completely seperate supply.

The IEE in Britain seems to have always been quite opposed to 3-phase in residential environments. Where 3-ph is used (and it would be a VERY big house, maybe a large guest-house or something like that), then they have rules regarding such things as the placement of phase barriers in boxes, ensuring that all sockets in one room are on the same phase, etc.

Our friends across the Big Pond may well feel uneasy at residential being 240V to ground, nevermind 415V 3-phase!



[This message has been edited by pauluk (edited 03-21-2003).]