Hope this is the right forum for this.
I am trying to choose a motor for a belt grinder. I have a 3HP TECO VFD. I connected it to a 3HP 4-pole motor, and when I crank the RPM over 4000, I get a DC bus overvoltage, and the VFD quits on me.
It's my understanding that the motor behaves like a generator, sending power back to the VFD, and the VFD doesn't like it. My wild guess is that this is related to the speed of the motor, since I would expect a generator to pump out more juice at high speeds, and because the problem only happens at high speeds.
I turned off DC braking and deceleration; it didn't make a difference that I can detect.
Is there any difference between 2-pole and 4-pole motors when it comes to creating overvoltages? If I get a 2-pole motor and run it at the same RPM, will I have the same problem? If so, I might as well get a bigger drive pulley and keep the existing motor. If not, maybe I can squeeze higher RPM out of a 2-pole motor.
Thanks for any light you can shed.
I am trying to choose a motor for a belt grinder. I have a 3HP TECO VFD. I connected it to a 3HP 4-pole motor, and when I crank the RPM over 4000, I get a DC bus overvoltage, and the VFD quits on me.
It's my understanding that the motor behaves like a generator, sending power back to the VFD, and the VFD doesn't like it. My wild guess is that this is related to the speed of the motor, since I would expect a generator to pump out more juice at high speeds, and because the problem only happens at high speeds.
I turned off DC braking and deceleration; it didn't make a difference that I can detect.
Is there any difference between 2-pole and 4-pole motors when it comes to creating overvoltages? If I get a 2-pole motor and run it at the same RPM, will I have the same problem? If so, I might as well get a bigger drive pulley and keep the existing motor. If not, maybe I can squeeze higher RPM out of a 2-pole motor.
Thanks for any light you can shed.