Powerflex 755 current doesn't go zero after stop

bornwild

Member
Join Date
May 2010
Location
Riyadh
Posts
429
Hi guys,
We have PF 755 induction Flux vector control. When the drive stops the current doesn't drop to zero. It stays for 20 seconds. What parameter I need to set.
 
Is tourque proving enabled? That sounds like the brake set process on a hoist with torque proving enabled. If so I don’t think you have any issue.
 
Is tourque proving enabled? That sounds like the brake set process on a hoist with torque proving enabled. If so I don’t think you have any issue.

The drive is used on the pumps to pump hyrdaulic oil. Which parameter is torque proving? Do I need torque for this kind of application?
 
How is the drive controlled (PLC comms, hard I/O, HIM)?
What does the drive display read when the motor reaches zero speed but there is still current being generated (Stopping, Stopped, At Speed, etc)?
What level of current is being generated as a percentage of full load current?
Is the drive being stopped using the stop command/input?

Keith
 
Depending on the type of pump, this may be something that the original designed programmed on purpose. It may be that there is a DC Braking routine implemented on stopping, to prevent back-flow or for some other reason. We cannot address this for you from afar, you need to see what it is doing and why. Disabling it my have dire consequences.
 
According to your screenshots the VFD is still running, just at 0.231 Hz.
The "Commanded Forward" indicator shows that whatever is controlling the drive is still telling it to run, just at a very low speed.

This doesn't appear to be something that can be changed from the drive parameters.

As jraef stated, there may be a good reason it is doing this during shutdown and its hard for us to tell from here.
 

Similar Topics

We have 4 PowerFlex 755 drives that have been running for years. Each drive runs two motors. Recently, two of the eight motors began cogging at...
Replies
3
Views
705
I have a powerflex 755 , every time the power is cycled on the drive the overload current changes from the setting of 1581 to 33. We have to go in...
Replies
3
Views
2,090
Hi All, I have a lifting/hoist application that I am using a powerflex 755 1hp drive. I am using a 1/3hp SEW gear motor that is rated at 0.57A...
Replies
3
Views
4,960
Powerflex 755, running 2 weeks, and faulting with code 17 input phase loss.
Replies
3
Views
145
Hi All, This is my first PowerFlex 755 drive setup and I am having an issue with when I start the drive it runs at my minimum speed 5Hz, but...
Replies
10
Views
343
Back
Top Bottom