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Why can't I run my 60hz motor on 50hz?

Why can't I run my 60hz motor on 50hz?

Why can't I run my 60hz motor on 50hz?

(OP)
I have a small dual voltage 120/230 single phase motor that I'm trying to run on 50hz but it gets hot. If I run it at 220 or 230 60hz everything is ok. If i run it at 220 or 230 50hz it slowly increases temp. I let it get to 200 degrees before I decided it wasn't going to stop increasing temp.
My power source is an "International Power Source" Model #1251 pc. Distributed by Panel Components Corp, Iowa.
The output of my power source is verified.
Whats going on?
I'm preparing this little gizmo for shipment to Spain where they use 230v/50hz.
thanks

RE: Why can't I run my 60hz motor on 50hz?

Check if this motor has a centrifugal switch. If that is the case, the starting winding is not disconnected and overheats the motor since the switch does not reach the disconnecting speed while supplied with 50 HZ.

Another concern is flux saturation. To prevent magnetic saturation of the stator and rotor laminations, the ratio Volts/Hz must be keep close to a constant.
220V/60HZ = 3.66
At 50 HZ Voltage = 50*3.66 = 183.3 Volts.
Magnetic saturation creates considerable amount of extra heat too.

RE: Why can't I run my 60hz motor on 50hz?

Short quote from Hubert, C.: Electric machines.

Operating an induction motor at significantly below rated frequency, such as operating a 60Hz motor at 50Hz, causes a significant decrease in magnetizing reactance and, because of magnetic saturation effets, an out-of-proportion increase in magnetizing current. The net result is severe overheating of the motor windings.

To prevent overheating, a reduction in applied frequency must be accompanied by a reduction in applied voltage. Simply staded, the ratio of voltts per hertz must be kept constant (like with a VFD).

RE: Why can't I run my 60hz motor on 50hz?

(OP)
Thank You.
I had been told by a motor rebuilder that the voltage wasn't the issue and that I was probably still operating in the start winding even though it tached at 5/6's (50hz vs 60 hz) of the rated motor speed (1450-1725rpm). So I disassembled the motor to ensure everything was working properly. It was. He also told me that's why you see many motors today stamped with 50hz/60hz on the motor plate. Whats up with that?
Anyway thanks alot. It's funny, ya think your pretty savy and then ya run across guys like you...

 

RE: Why can't I run my 60hz motor on 50hz?

If there's some type of cooling fan attached, it will also have less speed and less cooling at lower frequency.

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