Crown/Wilton 440v grinder

L

Lordbeezer

Forum Guest
Register Today
Picked up a 8 or 10" bench-pedestal grinder.tag says 440v.3 phase.motor has 9 wires coming out.3 pairs of wires joined together .other 3 go to toggle switch.goggling says MOST of the time 9 wire motors are dual voltage.tag has one set of values.I have a 3 phase motor to make a rpc.have a lenze vfd 3 phase 400-480 in and out.dont think that's going to help.can I rewire to run on 220v.or is transformer better.thanks.Phil

image.jpeg

image.jpeg

image.jpeg

image.jpeg
 
Best option is probably a 220 to 440 step-up transformer in front of the VFD that you have.
It's either that or reconfigure the motor for 220 volt and buy a 220 volt VFD- probably a wash as far as price goes-
Mark
ps Simplest way, Phil, would be to make a static phase converter with a capacitor and reconfigure the motor for 220. However, it requires phasing of the windings properly and I'm not sure I could talk you through that. Other issue is that the motor would only develop about 2/3 power.
 
Last edited:
It sounds to me that the motor can be reconnected for low volts with those 9 wires. I cannot find my book that tells which numbers go together, or I would tell you how to connect it. There are two different motor types, Star and Delta windings and the connections differ. A motor shop should be able to tell you how to connect it for 240V or look at another 3 phase motor with a nameplate for dual voltage.
 
here are the schematics for star and delta wiring of 3-phase motors, they can be supplied by lower voltage in delta connection and in higer voltage in star connection. The wide lines represent the jumpers on the connection board.

Star_Delta_Schematic.jpg
 
for low voltage WYE connection:
1-7,2-8,3-9 are paired and get the 3 power legs
4,5,6 are shorted together
 
Back
Top