mcclary's electrical
Senior Member
- Location
- VA
Today, I worked on removing a 40 hp diesel motor and converting it into a 30 hp electric motor. 240 volt single phase. Feeding a rotary phase converter (40 hp converter).
At the motor I mounted controls and wired starter. 240 coil on starter. I used control voltage from b&c phase, and tried to run it. When the starter pulled in, it was short cycling very quickly, chattering. If I determed the motor leads from the bottom of starter, the starter would engage fine, hook leads back up to motor, and the starter chatters.
After verifying there were no loose control connections, I changed my control voltage taps to a&b phase. The starter performs perfectly.
I'm trying to understand why the coil doesn't perform off of b&c phase, but it performs perfectly on a&b phase. I read 240 volts at the coil either way.
What is it about the rotary phase, that the coil does not like?? What does such a voltage look like on an oscilloscope?
At the motor I mounted controls and wired starter. 240 coil on starter. I used control voltage from b&c phase, and tried to run it. When the starter pulled in, it was short cycling very quickly, chattering. If I determed the motor leads from the bottom of starter, the starter would engage fine, hook leads back up to motor, and the starter chatters.
After verifying there were no loose control connections, I changed my control voltage taps to a&b phase. The starter performs perfectly.
I'm trying to understand why the coil doesn't perform off of b&c phase, but it performs perfectly on a&b phase. I read 240 volts at the coil either way.
What is it about the rotary phase, that the coil does not like?? What does such a voltage look like on an oscilloscope?