Powerflex 40 stumped me!
Powerflex 40 stumped me!
(OP)
I have a AB powerflex 40 VFD that is running a belt. The Operator controls the speed of this belt with a dial that inputs a analog 0-10v into the analog input of the drive. The drive is terminated with the factory jumper at the "stop" input, and the start input is run thru an auxilary contact from the motor starter that is between the drive and the motor. No other digital inputs are used. This thing drops to 5htz randomaly with out a fault. And then comes back to the desired speed just as randomaly as it went out. My analog is good and I have 24v at the start input. Has anybody experenced this and can tell me what the heck is going on?






RE: Powerflex 40 stumped me!
5Hz is about 3/4V variation.
You could have a dirty pot.
The pot could be under-rated.
The pot could be coarsely wound and be vibrating between winds.
If you aren't using a pot you could be having a ground loop problem.
Or a strong local radio source could be imposing a voltage onto the control wires when say, a hand radio is transmitting.
Are the 0-10V lines properly twisted?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Powerflex 40 stumped me!
RE: Powerflex 40 stumped me!
RE: Powerflex 40 stumped me!
RE: Powerflex 40 stumped me!
I'd be more likely to say the drive is set to a minimum operating speed of 5hz and that the analog is being lost giving a 0V input which tells it to run at 5hz.
RE: Powerflex 40 stumped me!