Rough Starting/Running Variable Speed DC Motor

[bronzeo]

Yesterday, I recieved a 1 1/2 hp DC Dayton motor with controller. It requires 220 ac input and is a permanent magnent motor. It was listed as new, by seller and looks unused with some sitting age on it. As we try to operate it it doesn't start very easy, and requires the dial (l-10) to be turned to about 4 to get motion to start. The motor has a heavy pulsing or surging sound which deminishes somewhat,at it highest speeds. High speeds are attainable. It runs without bad vibration, and the problem is obviously not bearing related. The motor sells through Grainger for near a thousand dollars. I am not real experienced with motors, though understand them some. How bad would you "assume" that I am burned? Bronzeo

 

[azzmi]

Hi,
First of all if you have an oscilloscope, I recommed, check the motor's armature voltage waveform. This will help to point the problem comes from the controller or the motor. Ah, I missed a thing, is your motor a brushless PM motor or a classical commutator DC motor without excitation windings?

Regards