I'm continously getting "cant pump down" alarms on Circuit B. The alarm is more of an alert it doesnt shut the machine down. I discovered this on a pm when I went into alarm history. Anyway this particuliar unit uses the exv for pumpdown, I confirmed proper operation of exv. My thoughts are that there is some internal problem with compressor, because even when calling for cooling this circuit doesnt have the capacity that circuit A has. Circuit A holds the load at 50 percent while circuit B cant hold the load at 100 percent. beside my suction pressure being a little high about 73psi and my subcooling being a little low about 5 degrees everything else appears normal.

My question is does anyone have any info on these Mcquay scews that I could trouble shoot the compressor further???