Anyone out there ever had an intermittent phase loss problem on these drives? 208v, 40HP motor, Not motor, not motor contactor, does have an overload attach, it’s an EC Controller, and it does not have a C1 adjustment on it, so I can’t even change the sensitivity of the phases, already went through the whole controller with EC tech support, pretty much said it’s not on there side good luck. Any suggestions? Thanks

I think the only move here is to put a 3 phase power quality analyzer on it. If it’s building power it’s not your problem. If it isn’t building power it’s the drive.

Had a similar problem with a hospital performing monthly testing of their backup emergency power. It had no provision for a pre-test signal to the controller. If the unit was traveling and the power was transferred, the drive was trashed. Found the problem as Dirt said. We rented an analyzer. The hospital was then liable for all the costs.

Drive is failing or one of the phase adjustments are out of tolerance. Is this on a newer machine or an old machine?

also are you running an encoder?

Motor is about 10yrs old, does have an encoder, it’s very random tho, it can run a few days, or run for 2 hrs before it shuts down, I sat and watched the controller during there chow runs… it in a jail, and it never shuts down, it has never shutdown when I was there, just get the call for it, reset and it takes off

The drive has an auto reset feature per specific time frame. Make sure it is enable. The drive also will loge the fault that shut it down. What fault or faults are you getting?

how long has the drive been installed for?

Id be looking at the motor contactor contacts. If it was a building power issue, you would most likely get an under voltage fault. Is it the original Sprecher/Shu contactor? Also, is it only faulted on the drive? Are you having to ANSI reset also?

I’ve seen the overloads fail intermittently.