50 Hz appliances on a 60 Hz power supply

Eriond,

If you connect a 60 Hertz motor to a 50 Hertz power supply:

The motor turns approx.17% slower;

The internal current goes up by approx. 17%;

The power (watt) goes down approx. 17 %; and

Mechanical cooling is less, because of 17% less turns.

The result is a higher current draw than designed for, and the insulation of the electrical wiring will deteriorate much more quickly - sometime resulting in a burn-out.

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Just my $0.02

Ok. How about the reverse case? A 50 Hz motor hooked up to a 60 Hz supply?

Two scenarios

A - voltage is unchanged, i.e. same as the nominal figure for 50Hz. Power output is same, current is same, torque is down by 50/60 = 0.833.

B - voltage is up by 60/50 = 1.2. Power goes up by 1.2, current is same, torque is same.

Note these figures are what the motor is capable of, what happens in practice depends on the load being driven. E.g. for a positive displacement pump (constant torque) A no good, B works. For a centrifugal pump torque increases by 1.2² = 1.44, and power by 1.2³ = 1.728 so neither works. (assuming motor is at design duty at 50 Hz). Need to consider the complete system.

Cheers......Codey

I used to work at Whirlpool in Dayton, Ohio managing our appliance testing. We had a separate 50 Hz supply for testing. Yes, it will impact your results if you do not use the correct source frequency and voltage.

However, that being said, it depends on what tests are being run. I would opt for getting the right supply voltage and frequency. If you are qualifying for any king of certification you will need to use approved calibrated equipment to do the job anyway.

Cert tests were typically managed by outside firms such as UL, etc.

Combat experience tells me that the 12 - 17% difference is trivial, Enjoy your cold beers

You said:-

Combat experience tells me that the 12 - 17% difference is trivial, Enjoy your cold beers

WRONG WRONG WRONG WRONG.

I worked for a large US computer company, and installed US equipment in europe many times - many, many problems.....till we showed them how.....

We are NOT talking MIL SPEC equipment here......

The original poster must test using the voltage and frequency of the customer. Nothing less is correct.....Foreign support trips and redesign are not cheap.....

Buy a rotary converter and.....test....test.....test....test....test....test

Eriond, If you assemble components and build a refrigerator, then ask your suppliers to provide parts that meet your specs. 50 HZ - 220 V. They will solve your problem for you.

Good luck,

James

Gentlemen,

The nominal voltage in most 50hz countries has been raised to 240 volts, I am not saying that when you measure it, it is exactly 240, but you should build at least for that voltage. Whether there is a need to build a little afety factor in too, I am not at liberty to say, but I would.

I know that over the years a lot of US equipment that I have worked on, built for Europe had only 600 or 800 PIV Triacs, all these have to be replaced replaced with 1000 volt versions for reasons of spikes and reliability in the long run on 240 volts!!!

Remember that, it will save you a lot of $$$$$$

I have seen equipment with 600volt Triacs blow 50% of them on switch on!! And all was "tested" in the lab!!! NUTS, no testing was done......

Andy is 100% correct. Working in the industry, I know the gig since we built US spec and European spec products and they need to be approved by the relevant agencies, period.

I am totally with Andy on this one, I do not know why you doubled up on the thread about this subject but maybe you did not like the first answers you got.

You will get a lot higher failure returns if you do not get the right spec equipment. Do not listen to someone promising you a cold beer which he will not bring to you himself. It is no skin of his nose if your equipment goes wrong all the time.

I'm with you too, this is SERIOUS business. I explained in a previous post of a client who destroyed a (german made) air compressor by over-speeding it with 60 hz when it was designed with a 50 hz motor. I don't think Jman's note of everything being 17% is quite accurate though, there's other variables....motor saturation, internal overload tripping etc.

Please also read:

http://cr4.globalspec.com/thread/14181/Effects-of-60-Hz-Power-On-A-Device-Rated-for-50-Hz?frmtrk=CR4digest