I posted this question a few months back but did not get the answer and it could be that the answer is not out there. But here it goes.
I have a PowerFlex 4 that is used for the lift/lower and travel for a bridge crane. It uses a contactors to send voltage to either the travel or the lift motor. Now to the problem.
Very intermittent problem (maybe once a month) where the VFD faults out for an I/O comms fault and right after (less than a second) for a HW overcurrent fault. It is always in that order when I look in the fault query. I have changed out the entire drive including the I/O card. I have changed out the cable from the PLC to the VFD and ensured that it is shielded right. There are two other drives on both sides of the problem drive neither of these have ever had a problem. I have monitored where the hoist is at at the time of the fault and there is no pattern.
The PLC uses the 24VDC from the drive to a relay output card for fwd reverse stop ect. Is it possable that I could somehow be inducing a spike from the relay output card into the VFD causing this? It uses an analog card for the speed referance.
I have called my vendor for AB and they are stumped.
Any idea's???
Thanks
I have a PowerFlex 4 that is used for the lift/lower and travel for a bridge crane. It uses a contactors to send voltage to either the travel or the lift motor. Now to the problem.
Very intermittent problem (maybe once a month) where the VFD faults out for an I/O comms fault and right after (less than a second) for a HW overcurrent fault. It is always in that order when I look in the fault query. I have changed out the entire drive including the I/O card. I have changed out the cable from the PLC to the VFD and ensured that it is shielded right. There are two other drives on both sides of the problem drive neither of these have ever had a problem. I have monitored where the hoist is at at the time of the fault and there is no pattern.
The PLC uses the 24VDC from the drive to a relay output card for fwd reverse stop ect. Is it possable that I could somehow be inducing a spike from the relay output card into the VFD causing this? It uses an analog card for the speed referance.
I have called my vendor for AB and they are stumped.
Any idea's???
Thanks