We sent the drive to access and they said they found a bad capacitor. The customer has a monitor hooked up now recording data. I put the elevator on random car calls every 90 seconds for nine days and couldn't get the car to shut down. When I say this happens intermittent, I'd say once every 3 weeks. I agree with you on this being a common thing with the ovf drives. Problem I have is in my experience a drive issue isn't this intermittent. Especially as much as I ran that car testing it. Thanks for your reply.