so i have a powerflex 525 that im controlling via the terminal blocks DigIn's. Im using DigIn 6 for my other preset frequency, which ends up being A412 and that also allows me to use accel/decel 2 with that. the motor in question runs at 30hz when the DigIn 6 input is open, and runs at 60hz when the input is closed.
P041 is 12 seconds
P042 is .2 seconds.
A442 is 8 seconds
A443 is .2 seconds.
A410 is 30hz
A412 is 60hz
Once the machine hits a certain windows within the ladder logic it then turns on the PLC output and that is what controls my DigIn 6 on the drive.
If the machine is running in the 60hz range and i let off the pushbutton on the HMI the machine stops as it should immediately. My issue is when the machine is running at 30hz, it sometimes acts just as it does in the 60hz window, but then sometimes the brake engages and the motor sounds like it trying to pull 'through' the brake.
Whats throwing me for a loop is that fact that this in only happening intermittently. and i am unable to recreate the issue with any consistency. There is a dynamic brake resistor installed on the VFD, and A437 is set to 1. I have also set A550 to 0 since i am trying to stop the motor quickly. I can watch the ladder OTE turn off on my laptop, as well as see the light on the PLC screen itself turn off thats goes to the VFD for the FWD or REV command, BUT when this issue happens i can watch on the VFD screen that the RUN command on the display is still showing up. I thought perhaps it was noise that could have possibly somehow been keeping that input on the VFD hot for longer then needed, i pulled the control wiring out of the panduit and far away from any high voltage and nothing changed. Im perplexed and open to question comments and concerns.
P041 is 12 seconds
P042 is .2 seconds.
A442 is 8 seconds
A443 is .2 seconds.
A410 is 30hz
A412 is 60hz
Once the machine hits a certain windows within the ladder logic it then turns on the PLC output and that is what controls my DigIn 6 on the drive.
If the machine is running in the 60hz range and i let off the pushbutton on the HMI the machine stops as it should immediately. My issue is when the machine is running at 30hz, it sometimes acts just as it does in the 60hz window, but then sometimes the brake engages and the motor sounds like it trying to pull 'through' the brake.
Whats throwing me for a loop is that fact that this in only happening intermittently. and i am unable to recreate the issue with any consistency. There is a dynamic brake resistor installed on the VFD, and A437 is set to 1. I have also set A550 to 0 since i am trying to stop the motor quickly. I can watch the ladder OTE turn off on my laptop, as well as see the light on the PLC screen itself turn off thats goes to the VFD for the FWD or REV command, BUT when this issue happens i can watch on the VFD screen that the RUN command on the display is still showing up. I thought perhaps it was noise that could have possibly somehow been keeping that input on the VFD hot for longer then needed, i pulled the control wiring out of the panduit and far away from any high voltage and nothing changed. Im perplexed and open to question comments and concerns.
