Posted: 11/19/2008 1:44:57 PM EDT
[Last Edit: 11/20/2008 10:42:05 AM EDT by HELOBRAVO]
I have a rotary phase converter that I bought new from a reputable company to provide three phase power for a Bridgeport Mill I aquired.
My phase converter is rated for 5 hp, the "pony" motor I am using to generate 220v 3 phase is a new 220/440 3 hp induction motor. (I will be running a 220v 3 phase 1 hp motor on the mill.)
My problem is this: After about 45 seconds or so the 3 hp pony motor started smoking a bit, and of course I turned it off. It had smoke in the case and the shaft was hot, so it wasn't just buring something off.
It is a new motor and I have ohmed my windings and they are all the same even after the over heating.
(I did not turn the mill on so it's no consideration now.)
The motor is a nine wire induction motor which is wired correctly for 220 according to the sticker on it. .
If I remember correctly (After the rush to shut it down when I smelled smoke) I was only getting 110 volts to each of the poles on the mill.
Could my motor not be big enough to signal the converter to shut off the start capacitors?
Any help appreciated. Thanks.
Let me do some research and see what I can come up with. We just installed a rotary phase converter, so I will check up on it for ya, in case we end up having the same problem down the road.
ETA: Best I can come up with is that you smoked the windings. Scare up a megohmmeter and test the windings properly. The start capacitor should still be run on a centrifugal switch, so there is a chance that did go bad, since the capacitor cutting out is based on motor RPM and not load conditions.