Robicon: "A1 DC Bus Over Voltage"

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 there,

We are having the same problem here, but the drive didn't reach 20% to trip, just when we start the drive, it's directly shows "A1 DC Bus Over Voltage", and we've done things from our side are swap and replace power cell, replace output CT, replace output attenuator resistor and even we replace all card in the control section. The motor also disconnected from the load, which still didn't solve this problem. If you've solved this problem, kindly tell me how to solve this, thank you before.

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Split from HARMONY ROBICON-A1 DC bus Over voltage.