marke

Thanks Mario,

I exited in 2001, so not involved today, but a good milestone.

Hello AB2005

If the three motors are identical, and all operate at the same time, and at the same load, and are shaded pole motors, then this will work fine.

If the motors have a start winding along with a start switch to connect and disconnect that winding, then the impedance will be so variable, that the voltage applied to each motor will change and there will be issues.

It works well for shaded pole fan motors, but some of these motors do not like the PWM waveform and can overheat with increased slip losses.

There is a VFD designed for use with single phase motors, you would need one VFD per motor.

Best regards,

Mark

This page seems to have gone now.

If you provide this information to the motor manufacturer, they should be able to tell you the number of starts that is OK.

Check what the motor is capable of. If the start times are very short, then more starts are possible. It is a thermal limitation and the generic figures quoted do not represent you actual conditions.

ten 30 second starts are the same as 20 15 second starts if the start current is the same.