View Full Version : 220 to 220?

06-15-2007, 10:31 PM
Hey there;

Ok, my cousin is in America and shopping up some Grizzly equipment for a cabinet shop in Tullemore Ireland.

He was told while 220 volts is 220 volts, that the US uses 50Hz and the Europeans 60hz (Vice versa?) He's heard that the equipment will run a bit hotter, but no more than that.

Anyone know about using 220 V US to euro?


06-15-2007, 10:55 PM
The electricity in the US is 60 Hz. Europe is 50 Hz.

The motors in the Grizzly catalog (On line) do not specify operating frequency.

That said, many motors will work on either 50 Hz or 60 Hz with little difference in performance except for rotational speed. For the machinery that your cousin may be considering, the difference in the rotational speed should be of little consequence.

An E-mail to csr@grizzly.com should get your cousin's question answered quickly.

Of greater concern to me would be getting the machinery to Ireland. If Grizzly doesn't have customs services in Ireland, importation of the machines could be a nightmare for your cousin.

06-16-2007, 08:29 AM
U.S. 220/240 Volt is two phase, we get our 240 volts by adding 120 from two legs. European 240 Volt is single phase, the juice all comes through one wire, then goes back out through a second nuetral or ground. Different motors would be the easiest conversion.

06-16-2007, 03:15 PM
In either system the difference between the two wires is never more than 220 Volts, RMS. In our system we use a grounded center tap of the transformer while the European system grounds one side of the transformer. A 50/60 Hz, 220 Volt motor will work on either system safely.

I can't see any differece between the two systems other than safety. In our system it's 110 volts maximum to ground and in the European system it's 220 volts maximum to ground.

In our system a 220 Volt shock would be very rare as one would have to get across both hot leads to receive the shock. (Maybe that's why our system is the way that it is?) Most electrical shocks in the US are between voltage and ground or 110 Volts. In the European system a 220 volt shock is the probable one.

Cannon Fodder
06-16-2007, 04:23 PM
I'll second what Rich said. There will probably be some difference in the speed, but I'm guessing it won't be very noticable. I know electric clocks won't keep the right time due to the Hz difference, but microwaves work fine, and so should machines like saws... but I would definitely contact Grizzly and see what they have to say. I would also ask if this will effect the warranty on the machines.

Education: that which reveals to the wise, and conceals from the stupid, the vast limits of their knowledge. -- Mark Twain

06-16-2007, 10:48 PM
Interesting question.

I was told that my computer monitor failed due to the frequency differences.
Most power supplies are switchable, so I thought it would be fine to ust switch it to 120...I was told no.


06-17-2007, 10:03 AM
I was under the impression that the opposing sine waves of the two legs of U.S. 220V were taken advantage of to create magnetic fields to simultaneously push and pull the rotating part of the motor, where-as the European version of 220V has only the single sine wave, albeit a stronger one.

06-17-2007, 03:37 PM
The Grizzly motor, getting 220 V from the line might seem to be happy, but there are two things to keep in mind.

The lower frequency reduces the internal impedance of the whole motor by 17%, That means it will draw 20% more current for the same voltage (1.20 = 1/0.83). That extra 20% current means 44% more heat (1.2 squared).

The blade tip speed will be 17% slower, so for the same torque, you get 17% less power. The 3 hp motor just became 2.5 hp. So, you get less horsepower and more heat. You lose on both counts.

You really want to get a 50 Hz motor for this one...


Regarding the European 220 V wiring vs. ours... It should make no difference as far as the applied voltage goes. I do not know, but one leg of their 220 may be grounded in the same sense our neutral (white) wire is grounded. That is never true in the US 220 V (both leads being hot).

BTW, our 220 can be 230 or more...

06-17-2007, 08:46 PM
Nope, their 240 looks just like our 240 on an o-scope, after you take the different frequency into account.

-- Tim --

When I get to feeling guilty about my own excess and waste...
...I need only visit any large city.
On my return, I feel like a monk.

06-17-2007, 08:53 PM
Of course... a 50hz motor will run at exactly the same speed at a 60hz motor will running on 50hz...

While in the USA that's a nominal 3600 RPM for a two-pole motor (1800 for a four-pole), it'd be a nominal 3000 RPM anywhere the power frequency is 50hz.

It's possible (I don't know here) that those 240-volt motors may be wound for a resonance of something like 55hz. The impedance drop figure at lower frequency may not apply if their resonance is lower than 60hz. Impedance is a freaky thing, and may not track as we expect it to - you can have, for example, lower impedance than DC resistance, if you try for it. It's not common, but it can happen.

-- Tim --

When I get to feeling guilty about my own excess and waste...
...I need only visit any large city.
On my return, I feel like a monk.

06-17-2007, 11:24 PM
Like Tim says no real difference. We sometimes do call our electricity two phase but it isn't. The way that we use our electricity is by half phases. (Half phase A, 110 Volts and Half Phase B also 110 Volts) It only looks like oposing phases when the O scope is referenced to neutral or ground. If the scope is referenced to one of the phases (like Europe) then the O scope will display a single sine wave, 220 Volts RMS.

The dual phase thing 110/220 volts confuses almost everybody. Anybody who has had grade school science understands batteries and voltage but throw the oposing AC phase at them and they get confused. It used to confuse me until a crusty electrician reminded me about center tapped transformers and Mr. Kirchoff and his laws.

06-19-2007, 06:27 PM
Well, I'm glad that I'm not the only one confused about that. Thanks for clearing up another of my mysteries about alternating current. Some time back I downloaded some pretty good textbook type stuff on 'lectricity. Naturally the first book of the stuff was on DC, and it started with some real basic stuff. I got all of the way through it just fine, hummin right along. Then I got into the book on AC and it seemed to jump right in the middle of things. Needless to say it lost me real quick.

Steve Wilson
06-20-2007, 08:53 AM
Your monitor failed due to frequency? Unless your monitor is very, very, old or very, very cheap I kind of doubt that. Most fairly modern monitors are multifrequency if not multivoltage.