Nuance Plc fault

[David_Emmerich]

Hello again!!!
I have an interesting problem in our Boilerhouse control system...almost every morning when the sawmill starts to bring all of their large loads online, the 6 feedscrews on our fuel system drop out. We have run a recorder on the incoming 480 lines but only see a 1 or 2 volt drop. I put a recorder on the 120volt feed to the PC rack (AB logix5571) and saw it dip to 115 vac when the 6 drives shut down this morning. Any ideas?

 

[g.mccormick]

Are the feedscrews motors VFD controlled? What is the fault mode when "the 6 feedscrews on our fuel system drop out"?

 

[Manglemender]

Are the feedscrews motors VFD controlled?

Yep, sounds like noise to me too. i experienced something similar many years ago on a machine with loads of automatic positioning. Every time a big extruder nearby started and stopped, I would lose half of my encoder cards. The situation was resolved by moving the extruder to a different transformer.

Nick