220 V Motors

Yes, it could run, if 220v is the designed coil voltage. But running a three-phase motor from a single-phase supply will never be the same. Look at 3-ph vs. 1-ph.

Your post is extremely confusing. I can't tell if your talking 1 phase or 3 phase when your indicating 3 wire. Residential wiring would be single phase with 3 wires, L1, Neutral, and L2. L1 to L2 is 240VAC, and 180 degrees phase apart. This is generally sourced from a center tap secondary transformer, where the center tap is neutral, and grounded at the transformer, and at the service entrance of the dwelling (depend on NEC code if this is connected here, sub panels introduce confusion, but intent is to minimize stray ground offset voltage, on neutral). As center tap to L1 or L2 is half of the 240VAC, this is where the 120VAC is derived.

Is this what you are calling 3 wire?

I hope I'm not introducing more confusion.

Ignator

Sorry. I'm talking single phase only. In the U.S. 220 motors have 2 hot wires and 1 neutral wire. In Europe (I think), 220 has only 1 hot wire and 1 neutral. If I had a motor that was 220 V, 50 hz, how would it be hooked up to 220, 60 hz, disregarding the frequency issue?

GA.

Both motors operate as single phase, 230-240V line-to-line. And yes, you cannot ignore the frequency.

A second GA!

When I saw "three wires", I immediately assumed 3 phase, and that's a whole different can of worms.

I think the safe answer here is, no.

RAEF is the right one, with emphasis.

The european 220V is single phase, Hot / neutral.

The US "110V" is the same.

The US "220V" comes from a center tapped (and grounded there) transformer, that is single phase (0deg. + gnd + 180deg). No rotating magnetic field there.

Unfortunately, US electricians customarily call it 2 phases.

While the remainder of the world (?!) and profession calls the 3 120deg differences with rotating magnetic fields phases.

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Nothing helps, as a bit of semantical confusion.

yea, like\

Bi-phase (240 CT xformer fed with a single phase primary hence single phase

Two phase - Some obsolete power system

Three Phase.

US Residential is primarily 240/120 "single phase"/BI-Phase

Residential CAN be three phase. Very rare.

Business can be supplied some wierd power that can give you 120, 277, 208, 240 with the latter two being single or three phase. It can be supplied delta and Y.

Residential 3 phase can only be done with a rotary phase converter to make the 3rd phase 120' out of phase with the other 2. Most residential will be 240VAC 3Ph 60Hz up to 200A requires a separate service and a large phase converter.

In the UK, three phase is fed down the street, and one phase is fed to each house. This can be noticed on the occasion of a single-phase drop-out, where every third house loses power.

Getting three phase into one house involves tapping into the other two lines in the street - expensive, but do-able. The most difficult part is convincing the planning department three phase is required.

It may be that a similar approach is taken elsewhere.

Three-phase, I suggest, is irrelevant. In the USA, 220v is supplied from centre-tapped transformers on three wires. A 220 v motor runs on two live 110v wires with voltage 180° opposed. In Europe a 220v supply is between a live line and a neutral line. The motor will run on US or European supplies (British supplies are at 240v, which may be OK or not - enquire of the manufacturer). The casing should be connected to a local earth.

The voltage in all of Europe conformed some years ago to the UK standard, which is NOMINALLY 240VAC. The actual voltage will be slightly variable due to the length of cable runs and loads etc., but usually it will actually be between 220-230 VAC.....

Unless you live right next to the substation, where you might see more than 230 VAC.

This should still not be a problem for a motor that is marked with 50/60 Hz., but not all are. If the motor is only lightly to medium loaded, you won't generally see problems. But for a motor that is loaded to its max, and its not wound 50/60 Hz., and is running on the "wrong" frequency, the motor may overheat, especially a 60 Hz. motor running on 50 Hz..

Do not forget that the motor will run at a different speed on the "other" frequency......

Hi Andy,

I used to think that 230 V was adopted (around 1988) as a compromise between 240 and 220. As Germans say, are you wearing your English or your German hat now?

abraços

Snel

I checked up and as far as I can tell, from this link, the Uk has dropped their nominal voltage and Europe has raised theirs......You learn something new every day!!

http://en.wikipedia.org/wiki/Mains_electricity_by_country#Voltage_ranges

Here is a good map, the fine print is shown again below (the red is a bit off color, sorry!):-

Dear Mr. ronseto,

We should not ignore V/F Ratio, as it plays a vital role, and has adverse effect, if ignored - the motor will get damaged, and concur with the views expressed in Post No.5 and Post No.6

Thanks,

DHAYANANDHAN.S

Don't disregard the 50/60 hz difference. A running motor generates a back emf that opposes the applied voltage. Since it runs slower at 50 hz, it will generate less back emf and thus draw more current. Another factor is the lower inductive impedance of the iron core, which also results in more current. The motor will run hotter on 50 hz than 60 hz.

Keep in mind that also the capacitor value will change with frequency.

No it does not change its value with frequency.

Its effect may vary, but the value remains the same.

It is possible that you may need to change it out for another value for reliable starting......

With respect, if this is a (usually brush-less) capacitor started motor the value of the capacitance may not change but the capacitor has a purely reactive impedance which is inversely proportional to the supply frequency. That means the phase shift will alter and the torque will not be the same. You may need a different capacitor.

What you say is true, but what Dobi said (and I was answering) was absolutely wrong and possibly misleading....

Running a 3 phase motor on line plus ground or phase is like trying to trying to run a dog only on three legs, it will work but not correctly or well.

Even a dog with three legs can still bite one on the derrière, as can a current flowing in the ground/earth wire; it's just not the right place for a return current, on the basis of safety. The correct place for a return current on a single phase system is the neutral conductor.

But not in the USA on 220VAC.......neutral is not (technically) used to power a 220 VAC device.

A 220 VAC device is connected Phase end to Phase end and the frame is grounded. The connection marked as Neutral is NOT used to supply power. The ground connection is connected to the metal chassis of anything not double insulated.

The 220 VAC in a private house in the USA, as someone here has already posted, is a single phase transformer output, with a center tap as Neutral, often/usually at the substation. The neutral is fed to each dwelling, as is the ground, which is earth bonded, as two separate wires, though they start at the same point.

Many electricians call each hot leg a phase, its actually each half of the same phase. No change in phase angle, but it is often described as being 180°......also wrongly, and as being "a 2 phase output" which is blatantly wrong.

The big plus point is that touching any part of it will give you a maximum of 120 VAC to ground, instead of the 230 VAC in a UK installation if you touch the "hot" end. Slightly less painful.....

That damn Atlantic Ocean has caused no end of trouble over the years...

LOL!!!!

When I first arrived in Germany (1981), I was always told that British and US citizens were the same!! My blood boiled (as did that of my US colleagues!)!!!

I found the fix, I agreed with them and compared it to the similarities of Germans and Austrians......(The butt of many German jokes, like the Poles in the USA!)

They quickly changed their minds about the UK/USA comparison!!!!!

As I also pointed out that there was only a mark on the map to show where Germany ended and Austria started, whereby some 3000 miles of saltwater marked the borders of the USA/UK!!!!

Plus 60% of US citizens Families originated from Germany......not the UK!!!

The UK was somewhere in the other 40% with Italians, French, Polish, Spanish, Russian, Chinese, Japanese and more......

Andy, please excuse me but, if one connects the two legs of a centre-tapped supply to two channels of an oscilloscope with the 'neutral' as the signal ground, the two traces will be directly reversed - 180° out of phase. Why isn't that right?

You are correct that the two 120 VAC supplies are quasi "anti-phase", but it is in reality the same phase.

No phase angle as it is one and the same phase.

Not really worth describing.......or do you see a possibility that the phase angle will every vary? I do not, so I can safely ignore it.

If it were not for the neutral connection, you could not even show two traces in opposition to each other - seemingly -.........

The neutral connection is NOT used when supplying a 220 VAC device.

I suppose it is six of one and a half dozen of the other. Each to his own.....

I personally prefer to think of it as a single 220 VAC Phase, center tapped as neutral. Forgetting this can cause plenty of problems when strange effects are noticed in a house wiring system......

"Slightly less painful..."

Theoretically, that is correct. In practice, the conditions seem to be more important than the voltage. As a child I was literally knocked across a small room when my screwdriver accidentally touched a hot 120VAC (still-wet plaster splatter on the floor). Since then I've been shocked several times each (i guess I'm a little careless) by 120, 220, 240, and 208VAC, and once by 480VAC (one fiber of copper protruding through the electrician's tape). I could not detect any correlation between the voltage and the pain...

Then of course I've been shocked hundreds of times by Van de Graaff machines, at several 10's of kVs, usually on purpose, with no known ill effect. A number of Leyden jar discharges were always accidental and were commonly fairly painful, but of course of very short duration. Everything in this paragraph occurred while teaching physics...

And finally, I once stood on the very peak of a small mountain and watched St. Elmo's fire emanating several cm from my fingertip. I could not feel any pain whatsoever. I did NOT stay there long! Lightning did indeed strike the very spot a few minutes later.

You are of course fully correct.

The current (which is the part that kills) is dependent upon the resistance of the conductor and the voltage applied, and standing with bare feet up to the knee in water is a far worse scenario than on a dry floor with plastic boots on....(Rubber, to stop it decaying has considerable quantities of other chemicals that reduce its resistance considerably. Plastic usually has a higher resistance to both current and decay).

We had pure rubber boots available for when working on live switchgear in the RN, but I have forgotten how long they lasted, 6 months comes to mind.....but no guarantee.

Being that we were usually in the tropics would shorten their "life" even quicker......