Running British 230 volt/60 hertz motors in the US

[Meltrope3]

I'm looking at the possibility of acquiring a British machine with a ca. 1930 induction motor. Are there many folks in the US who regularly use machines made in Britain that run on 230 volt/60 hertz motors? Or is this simply too risky a proposition with older motors?

Is there a specific model of step-up transformer that people have found to be reliable and safe?

Has running the motor at 50 hertz caused any problems (other than reducing the maximum turntable speed)?

Thanks!

[gregbogantz]

Generally speaking, motors and transformers designed for use on 50Hz can safely be used on 60Hz with no problems. Devices made for use with lower power frequencies usually have more steel in their cores to reduce heat generation at the lower frequencies so they are quite comfortable operating at the 20% higher frequency. Operating a 60Hz designed device at 50Hz may cause it to operate a little hotter, but you can probably get away with it.

The other consideration is the effect the power frequency may have on the speed of the motor. If the motor is an torque-induction type which uses a flyball mechanical governor for speed regulation such as are typically used in the 1920s and 1930s vintage machines, you will have no problem with speed operating it at a different frequency. But if it is a more modern design with an idler wheel that couples the motor shaft to the platter, then the motor speed will change with power frequency and you will see that 20% shift in your platter speed as well. These types of drives will require that you change the motor shaft diameter (often it is a pulley that can be changed) that drives the idler wheel.

Any step up or step down transformer that is rated for the nominal motor current should work to change the operating voltage to what the motor needs. Be aware that many of the european motors had double windings (or a tapped winding) that could be operated at either 120 or 240 volts by a simple exchange of wiring to the motor. No external transformer is required to change the voltage on these motors. Most of the American 120 volt motors do not have this multi-voltage capability built into them and will require a transformer if you want to operate them on 240 volts.

[Meltrope3]

Thank you, Greg! This is very helpful!!