Unusual markings on motor nameplate.

[nmark]

I have inherited a motor with a nameplate marked
Y/YY
460v
30/93A
I am not familiar with Y/YY on nameplate and also not sure why different amperage ratings with only one voltage rating any insight would be appreciated.
Thanks in advance for any replies. If it were up to me motor would be a boat anchor.

 

[davidbeach]

2 speed, 2 winding? How many leads?

 

[waross]

It is probably a two speed motor. The amperages would support that conclusion.
respectfully

 

[stardelta]

Its a 2-speed motor, single winding. here in IEC land it would be described as Series star/Parallel star. The low speed power being 25% of the high speed but with equal torque over each speed. The series star point is internal and permanent, the parallel and second star point is made externally when connected for high speed operation. It will be a 2/4 or 4/8 or 8/16 pole winding.

Assuming IEC markings.......

For high speed operation, supply 2W 2U 2V and short out 1U 1V 1W

For low speed operation, supply 1U 1V 1W and leave 2U 2V 2W open

 

[stardelta]

Sorry......Its variable torque not constant, appologies for the confusion.