I have a laboratory installation with a 230 volt corner grounded delta system. The lab users will be plugging in 220 volt single and three phase instrumentation from Euorpean manufacturers. The installation has 220 volts wired to the receptacles, without regard to the phases. In other words, some single phase, two pole, three wire receptacles are connected between A and C phases (line to line). Other receptacles are wired between A (or C) and the grounded B phase (line to neutral). Will there be a problem with 220 volt appliances connected between the A&C hot phases (line to line)? I am concerned about a possible lack of internal fusing on both lines if the appliance is expecting to see a neutral connection. (On US appliances, I see a sinlgle fuse on the polarized hot conductor only.) Also, is there a possible problem with chassis grounds or other connections to the hot conductor?
In general terms, you shouldn't have any problems, as all modern European appliances provide equal protection/insulation on both hot and neutral conductors, and certainly do not allow a chassis connection to be made to the grounded conductor.
In fact throughout most of Europe normal domestic-type connectors are unpolarized, even grounding types, and therefore there is no way to guarantee which wire will be hot and which the neutral in any case.
Re the fusing, any internal equipment fuse will provide protection against overload. The equipment relies upon the branch circuit fuse/breaker for protection against shorts to ground. As most European countries wire their standard receptacles on 16A branch circuits, you should obtain an equal degree of protection to the cords so long as your lab recepts are on 15A breakers (double-pole for those wired phase A-C, of course).
On the 3-phase equipment, you might need to look at that a little more closely. Some parts of Europe used to have 127/220V distribution, so 3-ph equipment designed for that should run all right, so long it doesn't need a neutral connection (i.e. it was designed to be connected 220V delta only).
However, all modern European 3-ph equipment is designed for 220/380V (or more officially, 230/400V these days), so you wouldn't be able to connect this directly to a 230V corner-grounded delta. If the equipment contains only 230V single-phase loads within it, then you might be able to rewire it internally.
Re: Does 220 volt European appilances need a neutral connection?#135187 12/24/0201:19 PM12/24/0201:19 PM
fklusek: Echo all that Paul wrote. In fact, 230V without neutral is used in some countries in Europe. (e.g. Norway and Belgium) All single-phase equipment shall be designed to work with this system. Also the US 240V should be within the European 230V voltage tolerances. Therefore, the only problem I can see is the different frequency, but this is so obvious that I assume that you have already taken it into account.
Some 3-ph motors can be wired in both Delta and Wye to make it possible to run them on both 230 3-ph or 400V 3-ph. (And as you now, in some cases switching from wye to delta also be used as a way of starting motors, but that wasn't what I was thinking of.) If this is some other type of 3-ph equipment, it is likely to be 230/400V.
lyledunn: The US has unlike most other countries not standardized the electric supply. Instead the most suitable situation for each case is choosen. This means that just about any system you can imagine is used in the US. If I'm not mistaken a corner grounded delta system will give you a ground and three lines with only three wires. As one wire is at ground potential, a 3-ph circuit will only need two fuses or one double-pole breaker instead of three fuses (breakers).
Re: Does 220 volt European appilances need a neutral connection?#135189 12/24/0204:55 PM12/24/0204:55 PM
Lyle, Although 4-wire wye systems are now commonly installed in the U.S. for 3-phase service, from a historical perspective delta systems were very common and there are still many in use.
A corner-grounded delta is simply a 3-wire delta service in which one phase is grounded (earthed). Thus if phase B is grounded, you have 240V to ground on each of phases A and C, and 240V between phases.
Another very American system which you'll see mentioned in the General area on a regular basis is the 4-wire delta. This is formed by taking a 240V delta service and putting a ground on the mid-point of the winding between phases A and C. This system evolved as a convenient way to obtain 120V from a 240V delta service. A consequence is that although phases A and C are 120V to ground/neutral, phase B ends up at 208V.
As C-H said, the U.S. uses various systems. The modern wye service is generally available as 120/208V and 277/480V, for example (also 347/600V in Canada).
[This message has been edited by pauluk (edited 12-24-2002).]
Re: Does 220 volt European appilances need a neutral connection?#135190 12/27/0205:17 PM12/27/0205:17 PM
On a standard American service there is no separate earth line supplied by the utility company.
The neutral busbar in the main distribution panel is bonded to the casing, and is connected to a local ground rod, forming what in the U.K./Europe would now be classified as a TN-C-S system, i.e. basically the same as British PME except that the bond is at the main panel instead of before the meter.
Re: Does 220 volt European appilances need a neutral connection?#135192 01/05/0311:41 AM01/05/0311:41 AM
C-H wrote “In fact, 230V without neutral is used in some countries in Europe. (e.g. Norway and Belgium) All single-phase equipment shall be designed to work with this system.”
Do I assume right that houses in those places would be supplied with three phases as standard (this has been covered elsewhere (by Tex R, et al.) and that stoves/ranges/ovens/hobs etc. in those places would utilise all three phases without a neutral; i.e. they would be wired in a 230V delta arrangement plus earth (3+E)? This would be different than the 230V wye (4+E) referred to by Tex R in Austria.
BTW, where is Belgium (the correspondent, not the country ), I’ve not heard from him for some time.
Re: Does 220 volt European appilances need a neutral connection?#135193 01/05/0311:58 AM01/05/0311:58 AM
Hutch: I have also been curious about this, and have tried to find information. Came up empty handed. In fact, I think these systems could be too rare to have "tailor-made" appliances. Norway doesn't manufacture much equipment at all. (Ever since they found oil other industries has slowly disappeared, to the dispair of the government)
Belgian disappeared from ECN sometime early december: Perhaps he took an extended Christmas vaction? Or even a trip to the holy land: He did ask about Israeli wiring
[This message has been edited by C-H (edited 01-05-2003).]
Re: Does 220 volt European appilances need a neutral connection?#135194 01/05/0303:34 PM01/05/0303:34 PM
I suppose one could on these systems connect phase 1 and 2 to line 1 and 2 on the stove, and connect phase three to the stove's neutral lug. Line 2 and 3 on the stove could be bonded together. As long as the insulation on the stove's 'neutral' is fine (I can't see why it shouldn't be) this could substitute for a 230V delta, but it is not well balanced.
[This message has been edited by Hutch (edited 01-05-2003).]