Electrician Talk banner

Powerflex 400 25HP wird amp behavior

1K views 5 replies 3 participants last post by  Demetrio urrea 
#1 ·
Hello I have a powerflex 400 of 25HP for a 60amp 25HP motor, the motor have a belt that move the clarifier of milk. It is a process that requires strength to move.

So I try with the motor without the clarifier the vdf works well with a constant amp of 12 to the max of 50hz that is set up with a ramp of 600 sec.

Then I try with the belt that move the clarifier... The vdf start the ramp with a wird amp behavior like 10 sec 100 amp and then 13 amp for 10 sec.

When it gets to 50hz (the max) it starts the same behavior 13 amp when it reach the max RPM and when it decrease a little bit it gets 100 amp to get to the max RPM again.

In this vdf powerflex 400 I didn't see the % of torque options that the last one Fuji had.

Someone told me that powerflex 400 is not for power processed, they are focus in pumps and blowers more alike, and that I need a vdf vectorial like a powerflex 725.

What do you think...

PD: as the 100 amp is like 10 sec the protections dont show up.

¿What do you think?
 
See less See more
#2 ·
Amp readings on a vfd are only half of the puzzle. The vfd can adjust voltage so you need both numbers to make sense of whats going on.
Its easier to watch output torque.

Im guessing you did not replace the vfd for fun so did the original vfd fail when the clarifier was on production which means the disk stack could be dirty. Is the piston seal on the disk stack is leaking then the disks are dropping (hovering) leading to the motor hunting speed control.
Have you adjusted the vfd response to speed control. I believe the 400 is reading feedback from the motor to calculate speed control so if the machine is dragging then it gets a shot of water to push the disk stack backup the load suddenly drops and the vfd responds. Programming the vfd to be more flexible with the speed control may smooth this out.
95% of vfd problems i have dealt with on classifiers ended up being mechanical problems with the machine.
 
#3 ·
Amp readings on a vfd are only half of the puzzle. The vfd can adjust voltage so you need both numbers to make sense of whats going on.
Its easier to watch output torque.

Im guessing you did not replace the vfd for fun so did the original vfd fail when the clarifier was on production which means the disk stack could be dirty. Is the piston seal on the disk stack is leaking then the disks are dropping (hovering) leading to the motor hunting speed control.
Have you adjusted the vfd response to speed control. I believe the 400 is reading feedback from the motor to calculate speed control so if the machine is dragging then it gets a shot of water to push the disk stack backup the load suddenly drops and the vfd responds. Programming the vfd to be more flexible with the speed control may smooth this out.
95% of vfd problems i have dealt with on classifiers ended up being mechanical problems with the machine.
Well, no for fun, but to make another machine more important to run, so the clarifier have not been in any fault. the powerflex 400 dosnt read the RPM of the machine it dosnt even have their inputs active, so this is just its form of work. The voltage varies with the Amps its goes up and then down.

Some VFD allow to modify the torque they are working with, but this model dosnt, the last one that was a fuji does allow me to modify torque and it was like 110%
 
#5 ·
The drive is going into Current Limit in order to protect itself. As I said in the other thread, you have the wrong type of drive for this type of machine. The PF400 is an HVAC drive that is only for use on centrifugal pumps and fans that have variable torque requirements an no overload possibility. This machine needs a "Constant Torque" drive like the PowerFlex 753 or 755.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top