Powerflex 700 vector drive

[bobwithdana]

We have a Busse De-Pallitizer Hoist 10hp Motor with an allen bradley powerflex 700 vector drive with encoder and brake. During the high speed up and down movement we are geeting an F005 Overvoltage fault. This is what we have done so far to a system that has been working fine for 2 years.

Incoming voltage is in normal range
Replaced Brake Resistor
Replaced VFD
We also changed several parameters based on AB reccomened.

The Motor Megs fine but has not been changed.

Lowereing the nomonal speed helped for a little while but its getting worse and faulting more and more. Current is always withing specs.

NOTE: This F005 fault is not occuring when speed changes from high to low or when the motor is deacceling to stop. Just during the normal high speed running. In both the up and down travel.

Should we concider changing the motor or are there any other suggestings.

Thanks a lot.
Bob Low

 

[bobwithdana]

quick correction.

I was just told that this F005 Is only happening while the Hoist is going down, Not up which makes sense,

Sorry for the miss above.

 

[leitmotif]

I was just told that this F005 Is only happening while the Hoist is going down, Not up which makes sense, Sorry for the miss above.

Has the load itself changed ie is motor trying to brake a larger load
OR
have you shortened the deceleration time ie braking harder?

Dan Bentler

 

[kamenges]

Has the mechanical gearing changed or are there lower mechanical losses in the system? It almost sounds like the system is moving more freely than it used to so the mechanics of the system are not providing the "drag" they used to. All that energy now goes back to the drive and the drive needs to get rid of it.

Keith

 

[jseavers]

If you can, put a meter on the DC Bus and watch the voltage. This will show you what point you are getting a increase in bus voltage. most of the time increasing the decel will help.

 

[OkiePC]

I would carefully check the brake against specs. I the brake is electromechanical and has worn, it may operate more quickly that the parameters of the drive are set up to deal with. It also may have been damaged and be adding additional mechanical binding. Most brakes are designed to fail safe so that as they wear, they lose their ability to release. Most of them require a certain amount of attention to detail when replacing wear surfaces too. We have some drive problems that were similar and ended up being caused by the difference between a .030 and .050 gap setting...

 

[alan_505]

When checking the DC bus voltage check at the brake resistor terminal at the same time as the drive DC bus terminals, also see if the resistors are drawing current during the high DC bus voltage conditions.

Alan