[Rocksalt]

Had some wicked rain yesterday w/thunder. Machine alarmed out 9 times with "W-75 Alarm D". It had some comments after it about voltage. I can't remember exactly what it said as I thought the alarm would be in the alarm code list. To my knowledge it was a deviance of voltage to great alarm. This is on a LU-35M with OSP5020L control. After seeing the alarm on the NC I checked out the main spindle drive. It's a VACII D30-A 37KW inverter. The alarm code on it was 34. I have the drive book for it and the number is not listed as well. I don't believe the problem has come up since the rain, but I want to make sure of the alarm and scope input voltage to make sure it's clean and steady. Before I go through that I want to be sure of the alarm so I don't waste my time looking for ghosts.

Does anyone have any reference to this alarm?

[Rocksalt]

ok, update for those interested.

The alarm says "VAC power supply change to large".

It just so happens that the drive units on the Okuma's are "VAC I,II,III" etc. I thought perhaps that "VAC" meant the incoming AC supply, wrong.

Update again... the "VAC" could in fact mean AC voltage. In any event, the problem is the drive is seeing a 6% change in input voltage during the regen of the drive for braking. Hard to see unless you have a good meter or O-Scope.

Maybe this post will help someone in the future.