VFD skipping accel rate intermittently
VFD skipping accel rate intermittently
(OP)
MGM (italian) Motor on Duff Norton Actuator
230v 3phase 50/60Hz
0.66kW (~1HP) @60Hz
Leeson 174276 1HP VFD
3ph 208vac input
Accel 2s (0-60Hz)
Decel 1s (60-30Hz)
Stop 0.1s (30Hz-0)
Been running this actuator in and out for a day & 1/2 w/o a problem. Was getting some data points and increased the accel time to 5.0 seconds, and when it retracted, the VFD started to ramp, then jumped to full speed (60Hz). I tried about 5 more times, and it did it 4 out of 5 times, the one time it didn't do it.
I reduced the accel to 1s and then 2s, and it still does it intermittently. The motor is suitable for inverter duty, is not hot, nor is the VFD. No error codes. I'm just running the actuator, no load.
Any ideas why my VFD is skipping the bulk of the accel ramp intermittently? Only on retract stroke, has not happened on extend stroke yet...
Thanks
230v 3phase 50/60Hz
0.66kW (~1HP) @60Hz
Leeson 174276 1HP VFD
3ph 208vac input
Accel 2s (0-60Hz)
Decel 1s (60-30Hz)
Stop 0.1s (30Hz-0)
Been running this actuator in and out for a day & 1/2 w/o a problem. Was getting some data points and increased the accel time to 5.0 seconds, and when it retracted, the VFD started to ramp, then jumped to full speed (60Hz). I tried about 5 more times, and it did it 4 out of 5 times, the one time it didn't do it.
I reduced the accel to 1s and then 2s, and it still does it intermittently. The motor is suitable for inverter duty, is not hot, nor is the VFD. No error codes. I'm just running the actuator, no load.
Any ideas why my VFD is skipping the bulk of the accel ramp intermittently? Only on retract stroke, has not happened on extend stroke yet...
Thanks





RE: VFD skipping accel rate intermittently
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: VFD skipping accel rate intermittently
RE: VFD skipping accel rate intermittently
Keith Cress
kcress - http://www.flaminsystems.com
RE: VFD skipping accel rate intermittently
Motor OL Current
Motor NP FLA
Of course I was operating from last years startup and did not change one and would not you know it that the other needs the same info. WTF? Why would some insane firmware designer make two parameters that do the same thing?
The mechanical checkout guy was looked over his stuff and said its my fault that the drive is overloading. Of course I look over my stuff since I know that Mr Murphy is right beside me. And stick the nameplate in the other parameter.
RE: VFD skipping accel rate intermittently
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: VFD skipping accel rate intermittently
JRAEF, I control it with discrete PLC outputs (dry relay op) which were only a few inches away. It was a really simple PLC program I wrote just to test the actuator, so I cannot rule out an out-of-sequence input that my program didn't handle well, but I didn't have a lot of time to troubleshoot, and it seemed fairly insignificant in relation to the test at hand. I wanted to be sure that there's no way the actuator motor could have had anything to do with it, I'd never seen one do that before, and never seen this motor (MGM) before.