Ncg249
Member
Hello everyone, I'm new here.
First of all I just want to say that you guys are very knowledgeable and reading your posts on here has saved my butt a couple times. I'm a young guy, new to the industry, and basically the only person in my facility with any controls experience at all on my shift. I'm by no means helpless but I do have a question for you all.
I have a powerflex 40 VFD that kept giving us an "FO4" fault. Undervoltage. The root cause for this in my opinion, is the fact that the contactor connected to the safety circuit for this machine is on the line side of the VFD. Whenever an operator opens the safety doors, the contactor opens and the VFD loses power. Sometimes they don't have the door open for very long though, and the bus capacitor drains just enough to give us our "FO4" fault. Then maintnence has to be called out to manually reset it.
Anyway, I was tasked with fixing it. The cabinet is a mess and there's no prints for it anywhere. After talking to a controls tech on another shift, we decided to change the auto restart tries to 3, and the auto restart timer to 0. This way the fault has been clearing on its own, and we haven't had to send anyone out to clear it manually. BUT, a controls tech on another shift has recommended that we set the restart timer back to 1.0. When I try that, instead of restarting the VFD it simply gives me an "F33" fault which appears to be the auto restart failing. I have tried this from .1 to 1.0. It only works when the timer is set to 0. Do any of you experienced guys have an explanation for this? I am not quite understanding why it is behaving this way.
Thanks, and happy to be here. Hope to become an active member of this community.
First of all I just want to say that you guys are very knowledgeable and reading your posts on here has saved my butt a couple times. I'm a young guy, new to the industry, and basically the only person in my facility with any controls experience at all on my shift. I'm by no means helpless but I do have a question for you all.
I have a powerflex 40 VFD that kept giving us an "FO4" fault. Undervoltage. The root cause for this in my opinion, is the fact that the contactor connected to the safety circuit for this machine is on the line side of the VFD. Whenever an operator opens the safety doors, the contactor opens and the VFD loses power. Sometimes they don't have the door open for very long though, and the bus capacitor drains just enough to give us our "FO4" fault. Then maintnence has to be called out to manually reset it.
Anyway, I was tasked with fixing it. The cabinet is a mess and there's no prints for it anywhere. After talking to a controls tech on another shift, we decided to change the auto restart tries to 3, and the auto restart timer to 0. This way the fault has been clearing on its own, and we haven't had to send anyone out to clear it manually. BUT, a controls tech on another shift has recommended that we set the restart timer back to 1.0. When I try that, instead of restarting the VFD it simply gives me an "F33" fault which appears to be the auto restart failing. I have tried this from .1 to 1.0. It only works when the timer is set to 0. Do any of you experienced guys have an explanation for this? I am not quite understanding why it is behaving this way.
Thanks, and happy to be here. Hope to become an active member of this community.