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#134114 - 10/25/02 08:25 AM 400V - scary or not?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
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?

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#134115 - 10/25/02 01:04 PM Re: 400V - scary or not?
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2343
Loc: Vienna, Austria
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.

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#134116 - 10/25/02 01:17 PM Re: 400V - scary or not?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
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?

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#134117 - 10/25/02 09:27 PM Re: 400V - scary or not?
CTwireman Offline
Member

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
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.
_________________________
Peter

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#134118 - 10/26/02 07:12 AM Re: 400V - scary or not?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
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.

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#134119 - 10/26/02 11:15 AM Re: 400V - scary or not?
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2343
Loc: Vienna, Austria
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.

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#134120 - 10/26/02 03:57 PM Re: 400V - scary or not?
Belgian Offline
Member

Registered: 10/10/02
Posts: 177
Loc: antwerp
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).]

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#134121 - 10/26/02 04:43 PM Re: 400V - scary or not?
CTwireman Offline
Member

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
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!
_________________________
Peter

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#134122 - 10/27/02 07:02 AM Re: 400V - scary or not?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
 Quote:

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.


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?

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#134123 - 10/27/02 10:37 AM Re: 400V - scary or not?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
 Quote:
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!


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.

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