Carrier 30HX T051 Alarms

[seawolf 1]

Went on a job yesterday with a 30HXC126R-640AA , S# 3002Q01843 water cooled machine. The customer is having T051 sub. 3.5 (Single phase current loss) alarms very regular. He has had Carrier service there since start up. They replaced the CCP and I beleive the MBB with no results. The customer asked my company to come in and look at it. The only Lit. I am finding on HVAC Partners is start up, nothing else. The comp was down when I arrived. I megged the mottor, looks good. Contactor is in need of rebuild or replacement. Customer wants quote. Checked MTA setting in navigator and the header on the CCP. Both match up with the book. For giggles I swapped the Toroid's between B & A compressor to see if the alarm will follow. This is a 460v XL start comp. All lugs were tight and no signs of wire overheating. Before I changed the Toroid's I was able to get the comp to trip once. It was unloading due to setpoint overshoot. After I swapped the Toroid's it ran about 2hrs in my presence with no issue. Called customer today and still no trip. Not satisfied at this early stage with calling it cured.

Any of yall run in to this before?

[Dallas Duster]

I would change out the contactor if you are saying that it's bad . Looks like it's across the line start , and not wye-delta.

[seawolf 1]

Just waiting on customer approval with the contactor and yes its XL start