DC Motor Drifting/Speed Issue
DC Motor Drifting/Speed Issue
(OP)
I have a 1HP DC Motor driving a fleeter that reverses direction upon command. I am using a speed reference from another dc drive to control the speed of the fleeter (through discrete adapter board). Both of these are driven with an older model AB 1395 Drive. With a 0 speed reference coming into the fleeter drive I am commanding the fleeter motor to be at 0 speed but the motor will drift. I can remove the speed reference cable at the drive and it will still drift. I can adjust the offsets in the drive and eliminate the drifting but that causes the motor to run faster in one direction than the other. All of this just started after replacing the discrete adapter board. I tried another board - same thing. Is there anyway this could be a motor issue and not a drive issue?





RE: DC Motor Drifting/Speed Issue
Keith Cress
kcress - http://www.flaminsystems.com
RE: DC Motor Drifting/Speed Issue
RE: DC Motor Drifting/Speed Issue
I don't know how hard it would be, but a test would be to swap the drives. If the drift follows the drive you have it.
I can think of no mechanism thru which the motor could cause this. And your prox as described shouldn't be doing it either.
Older drives relied on lots of analog circuitry that can start shifting as the components age.
The fact that it started after the I/O board change is either pure coincidence or you static zapped the drive during the work. This kind of problem is typical of 'zapped' analog circuitry.
Keith Cress
kcress - http://www.flaminsystems.com
RE: DC Motor Drifting/Speed Issue
RE: DC Motor Drifting/Speed Issue