Nidec c200-021 VFD rotating at zero reference

[sharkyh2o]

Lesson Motor 230VAC-1.2A-1700RPM-62.5PF

I am having trouble understanding this. My motor rotates at 0vdc reference with the run forward command. Even in pad. I can correct this by increasing the RPMs to 1800. it took me quite a bit of time to track down a remedy but i do not know what the relationship would be to cause this.Nidec service is unavailable right now so i was hoping for some explanation or advice on something I am missing. Thanks for any consideration.

 

[widelto]

Can it be that your minimum speed is not zero, I mean, that is written in a parameter.

 

[sharkyh2o]

Thanks for the reply widelto
Min speed at zero. I unwired all reference and still rotation.
I used keypad reference and started the drive also. Same result when 0 reference was given, slow rotation.
Defaulted back to factory settings at least a dozen times and finally put in each parameter at a time. When setting rpm parameter is when the drift occurs.

 

[widelto]

Can you observe commanded speed on your keypad ?, it must be zero.

 

[cidchase]

I'm guessing the VFD has a problem. BUT, where is Snow Shoe?

 

[sharkyh2o]

Yes I can observe 0 Reference. Changing parameter 0.007 from 1800 to 1700 causes it to drift. i can do it under enable and run Forward commands and see it happen. Wished i could upload a video.Snow Shoe, Pennsylvania is in the center of the state,24 miles away from Penn States campus, right off of Interstate 80.

 

[L D[AR2P#0.0]]

How about 3.001, that is the speed demand to the speed controller?


Use ScreenRec - you can record your screen and then post a link in your post.

 

[sharkyh2o]

I do see a bounce even without a reference wire into the drive.

 

[sharkyh2o]

Im not sure where this could be coming from

 

[sharkyh2o]

This is my real confusion. At 1700 RPM in pad 0 Reference on parameter 3.0001 but 1.78 output frequency on parameter 5.0001. At 1800 RPM both parameters are at 0

 

[GaryS]

The first question is did this just start or has it always been this way from the original installation.
As was said before what it the minimum speed parameter in the vfd
I often set the minimum speed up a little above 0 I have found the some operators will turn the speed pot down to 0 and leave the vfd in rum mode. I consider this to be a safety issue. if the pot gets bumped later it could lead to unexpected movement. if a drive is on I expect to not only see the status on the drive panel but also the motor in motion. the exception would be if I an using the vfd to hold position
you definitely identify what's going on there and take care of it

 

[sharkyh2o]

GaryS
Fresh out of the box. 110vac to 3 phase to check functionality compared to Unidrive M. Emerson supposedly ended the Commander series. and brought everything under Unidrive M 100-700 and you bought what you needed under one drive name. M200 was open loop, now the M200 is being phased out and the C200 is introduced. Everything is the same, just had to update my "Connect" software. The example i am using is for a press dancer and when full will cut the run forward signal and this would not be an issue, but right now it is just a motor on my desk and i am trying to understand why this is happening and why a change in rpm settings changes the output voltage.
Min clamp set to 0 in 0.0001

 

[GaryS]

What is the output frequency at 0 reference ?
you stated that you disconnected the pot reference
try to connect the reference input to the pot low terminal
you may have some floating voltage their also some pot don't go completely to 0 there may be a little resistance at the bottom.
I would never use a Unidrive
I lost a good client because of a bad one from the factory
but that's another story we can't get into here

 

[sharkyh2o]

GaryS
Reference Set To Voltage
@1700 RPM
0.05 Input Reference jumped to 0v
1.86 Output Frequency
@1800 RPM
0.05 Input Reference jumped to 0v
0.05 Output Frequency

Reference Set To Keypad
@1700 RPM
0.00 Input Reference set to zero on keypad
1.79 Output Frequency
@1800 RPM
0.00 Input Reference set to zero On keypad
0.00 Output Frequency

Liked the idea of jumping Ov but same results.

 

[Steve Bailey]

Could the problem be due to round-off error within the drive when the motor rated speed is set at 1700? Why would you want to set it to 1700 instead of 1800 in the first place?