Arrow 750 Z axis fault

[Ivan57]

I have a '94 Arrow 750 CT controller that will fault out the drive if "Z" motor is not warmed up to at least 100 degrees before initializing movement. Inductance on motor is compatable with my other machine, brake is dissengaging properly, and Maxax200 works fine in both machines. Motor spins freely (blocked head, removed coupler, applied 24vdc to brake) and sound fine. Any way it could be encoder?
Thanks, Ivan

[harvey wallbang]

Hi there. I work on a Cincinnati Arrow 750 with CT control,and by the sound of your problem i may have come across this myself.I was told this fault is caused by condensation forming in or around the drive encoders.Our machine was powerd down overnight in the winter,and no heating on in the machine shop overnight,so when i powerd up the machine in the morning it would throw up all kinds of alarms to do with X,Y and Z signal phase faults and encoder failures. We were told to put some heat on to the back of the machine in order to get it running again,and not to turn it off for no longer than a couple of hours,thus stopping condensation forming in the first place.
We used a propane space heater (set at a safe distance away) to blow some heat around the back of the machine.This took a good few hours,but it seemed to do the trick,and it started working again.I hope this helps,and good luck.