60 hz motor question

Given adjustments for heat, torque, and rpm, yes. (Depends on "ok")

All AC motors are just electromagnets - they may be designed for an optimum frequency, power, and voltage, but as motor controllers show, you can run them on just about anything AC, if you reduce output or otherwise adjust for losses and don't exceed voltage. Of course, if the adjustments are bad enough, you might end up having to settle for 1 hp out of a ten hp motor.

check with the mfg.....

Thanks for the reply.

NO! You are asking for problems.

"Smog" wrote in message news:d6icpv$foq$ snipped-for-privacy@newsg1.svr.pol.co.uk... Will a 30kw 440v (delta) 60hz motor run ok at 415v 50hz please ? Thanks.

It would be happy at 367V but not at 415 as, at the latter voltage the required flux density would be about 13% high and this would cause saturation and a high magnetising current. Not desirable. Voltage proportional to frequency is OK at frequencies below the design frequency

in article d6icpv$foq$ snipped-for-privacy@newsg1.svr.pol.co.uk, Smog at snipped-for-privacy@burrilllj.fsnet.co.uk wrote on 5/19/05 8:53 AM:

To prevent saturation of the iron, you should run at 367V. You will take a licking on speed and output torque and power.

Bill

Thanks you for all of your reply's.

The reason I ask is that I have a number of 60Hz 440v Motors ranging from

30kw, 22kw & 18.5Kw for sale. I have only seen them packed in a container at the moment but I believe there to be 4x 30s, 3x 22s and 2x 18.5kw. Any idea on what sort is price I should ask for them and what market to approach. I believe they where destined for Afghanistan several years back but where never sent. All the motors are brand new and unused. I presume that if wired through an sutiable Inverter set up they would be ok for UK use, in the assuption that frequency and voltage could then be tailored to suit ? If anyone on here is interested in them then please email me. They are destined for EBay eventually.

BINGO!

That's the key: make voltage proportional to frequency and you are "in the ballpark."

That's a fairly good sized motor he has!

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|> Smog |>

| It would be happy at 367V but not at 415 as, at the latter voltage the | required flux density would be about 13% high and this would cause | saturation and a high magnetising current. Not desirable. | Voltage proportional to frequency is OK at frequencies below the design | frequency

What's the possibility of running that motor on 480 volts 60 Hz?

If I were to control a motor with an inverter, I would specifically want an inverter-duty rated motor. Are yours? I am told US Electric were generally ok with their motors being controlled by speed drives as long as they were high efficiency motors, and they had insulation Class F. Do you know if your motors meet this?

j

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Licking on speed and power, but not on torque at 367V, 50 Hz. Torque will be determined by the load characteristics and typically full load torque will not vary much if V/f is constant. An example 60 Hz 240V 3 phase induction motor has a peak torque of 164Nm at 1349 rpm At 50Hz 200 V the peak torque is 160Nm at 1051 rpm but the starting torque is about 15% higher. At rated torque the current will be nearly the same in both cases but the speed will be proportional to frequency.

Are the motors rated for 440V or 480V? If rated at 480V, 50/60*480V is 400V, which is only 4% low.

No Mike, they are rated at 440v @ 60hz, well that's what it says on the motor reference plate.

It will worj at 20% lower speed and may run hotter

I guess they're old. Correct? Newer motors in that power range are rated for 480V nominal in the US market.

They are marked as 1996 when made but have all NEVER been used. They will be on EBay very shortly, just as soon as I get the write up's & pictures done for them.

I looked at one of your motors, and I see "Made in EU" on it. Where is "EU"? I thought that was Europe, and such a label would mention the individual country (Germany or whereever). Isn't all of Europe 50 Hz anyway?

I believe the motors where made in the EU for shipment to Afghanistan but the order did not complete.