Greg, my guess is a VFD is designed for run current. The instant inrush of current to start a motor is more than one can handle based on it's usage ratings. Any motor has a high inrush if started on the mains. Think of the momentary dimming of the lights when a well pump or compressor starts, and thats ON the mains.
I can set my accel and decel times down to 1/2 second and the lathe motor will start and stop in that time once I got all the parameters set correctly. The only 'problem' with setting the times so short is that the weight/mass of the spindle/chuck and drive train can't keep up with the motor and it will squeal the drive belt. Sort of akin to getting a fully loaded freight train rolling from a dead stop, or trying to stop one (quickly) when it's at full speed.
12-31-2015, 12:51 AM (This post was last modified: 12-31-2015, 12:56 AM by Hawkeye.)
It doesn't seem to make any difference how I set the ramps times. Sometimes, if I've disconnected and reconnected, the auto-tune will go far enough to run the motor (the manual says up to 80%) but always returns an error message.
I did megger the cable and motor. The lowest it would go on any lead is 186 Meg-ohms at 500 VDC. Plenty solid enough.
Good. This should let you generate plenty of questions. I took the week off and have pretty much wasted it on messing with this VFD. (That and picking up a Roland TD-12 drum kit.)
Mike
If you can't get one, make one.
Hawkeye, proud to be a member of MetalworkingFun Forum since Jan 2013.