Help!! Strange machine shutdown. No idea

Here is a strange one. Older VF1 was running fine a long run part. I was near the back of the machine when it all of a sudden made a slight growl, then totally shut off. The main breaker in our service panel also popped. I would swear that the breaker popped after the machine shut off. I fired it back up, have a 123 spindle drive fault but machine runs and is running parts right now.

I have no idea on this one. I could understand a power glitch maybe causing a machine issue but kicking out the breaker is really confusing me. My breaker runs up to about 80% of rating most of the time and will spike to 100% at peak spindle loads. Basically I sized the breaker perfect for the application and I really do not think that is the issue.

Also, Nothing else in the shop shut down but no other CNC machines were running at the time. Ideas? Haas thinks it was a power glitch and to just roll on. I am a bit worried but I have never seen a spindle drive trip hard enough to kill the machine, then just fire back up and go so I tend to think the machine was not the issue. Luckily when the machine shut down, it was not on a finish pass and did not damage a part.


hmmm....

Mine does the same thing and we are still sratching our heads.