A1000 and EPIC David standard speed mismatch

[0nezer0]

Hello,

I'm am engineer for a plastic manufacturer. We swapped out a oem motor with one of equivalent nameplate stats made by marathon on our roll stand. The new motor was auto-tuned in the floor prior to re-assembly to the gearbox.

On machine start I noticed there was some process issues and ended up using my foot per minute tach (this how we control speed at the PLC) to find out the new motor was having a -12fpm mismatch from commanded speed.

This middle motor is the master, the bottom and top motor follow the commanded FPM of the middle. The top and bottom have the proper speed output and set-point. They are commanded to be 65fpm, and we see 65fpm.

The middle is commanded to 65fpm, and it is only seeing 52fpm. The A1000 is setup with a -10 to 10v analog on A1 and no parameters were changed only the motor. The motor nameplate is 100% identical.

Is there a parameter to scale the input vs output? How will I tune this without getting into the PLC output scalar (password protected by OEM)

 

[kamenges]

Do you have access to the back of the motor? Can you tach the motor shaft and confirm it is going the speed the drive thinks it is?

Keith

 

[0nezer0]

Do you have access to the back of the motor? Can you tach the motor shaft and confirm it is going the speed the drive thinks it is?

Keith

Negative the encoder is on the shaft, so I would have to remove it to tach the motor. I just pulled paramters off another line and compared them and I actually do have a few differences that I didn't see from the screen; now that I used drive wizard I see the Freq Reference is setup to hz on the drive with the low speed; and on the proven working one it is setup for RPM.

Freq ref #1 on slow drive = 0hz
Freq Ref #1 on good drive = 1200 rpm

Due to *o1-03 Display scaling... [M] 2
*o1-04 Unit Selection of Frequency of V... [M] 1 r/min units


They aren't set on the drive that runs slow.

 

[0nezer0]

I think I will make the changes to the slow drive and try that tomorrow; those differences may have something to do with it.

d1-01 being 0 couldn't help, so the new one setup for RPM and 1200rpm setting may fix it.