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AKD Bus Over Voltage | 19 Jul 2018 | |

AKD Bus Over Voltage


I have an AKD-P02407 drive and have some strange behaviour while executing a wake and shake on a motor. The motor has an external braking resistor.

The wake and shake was very noisy and the drive faulted with bus over voltage.

I didn't have a spare motor that didn't require wake and shake, so instead I set the drive into Torque mode and set the feedback to none. When I enable the drive (with torque command of zero), I can watch the bus voltage steadily climbing until the drive faults on bus over voltage.

Would it be fair to assume that the drive is faulty? (I didn't have a spare drive to swap to at the time)

Comments & Answers

Joerg Muslewski | Thu, 07/19/2018 - 08:59
maybe you should exclude other causes before you exchange the drive.

Do you check the wiring ?
I guess "the motor has an external braking resistor" means, that you connect the resistor to the drive as it is described in the AKD installation manual and not anywhere to the motor phases.

Do you measure the DC-bus voltage ?
Does the measured value match the displayed one of  <VBUS.VALUE> or are they different, when the fault occurs 
If the measured value stuck at a level according to main power supply voltage (e.g.:560 Vdc @ 400 Vac), the drive is probably faulty. 

Gary_A | Thu, 07/19/2018 - 21:16
Hi Joerg,

Thanks for your comments.

The wiring looks correct. I will measure the DC-bus voltage and see how that compares to the VBUS.VALUE.
I might also try my test with the internal resistor.

Michael Brown_455 | Wed, 08/08/2018 - 18:07
Look at the drive GUI, Workbench.  Connect to the drive and ensure that parameter REGEN.TYPE is set to 1, indicating to the drive that there is an EXTERNAL regen resistor connected, then ensure the correct resistor wattage / resistance is selected in parameter REGEN.REXT.

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