krishnamoorthik

Dear,

we are having a SIEMENS HARMONY ROBICON GEN IV air cooled VFD with 9 cells without cell bypass with an input transformer voltage 4.16KV in this drive we are frequently facing a issue while we starting the drive. once the drive reaches its 20% of speed or some times 80% of speed  this is the error message(A1 DC bus Over voltage) displayed on the drive display and this triggers the drive to trip off. Once we acknowledge the drive and re initiate the start command then the drive running normal. kindly support me to sort out the issue.

Below Things which we done from our side:

We are having almost 6 drives of same configuration and we tried swapping the power cell(750 V,140A) from the other drive which is running normal but still the problem remains the same.

 Hi

Is the motor shaft fixed before starting and does not rotate?

An Overvoltage Fault is usually caused by an improperly set-up or tuned drive. 

You can use the following steps to troubleshoot this type of error.

Course of Action

1. Verify that the motor and drive nameplate settings match parameters in the motor parameter

2. Reduce the regen torque limit parameters 

3. Reduce flux regulator proportional gain and flux regulator integral gain 

4. If the failure is occurring in bypass mode, increase the energy saver minimum flux parameter to at least 50%.

New question published by rindiard is split to a separate thread with the subject Robicon: "A1 DC Bus Over Voltage".

Best regards
Jen_Moderator