100 trane model e

[t2]

working on 200 ton cgwcd trane chiller. 2 model e 100 tons each 3 unloaders. Comp one keeps tripping on oil. comp 2 stays running. seperate circuits. Comp one closest to entering evap and cond water. No mater what tghe water temp or pressure are comp one trips on oil and comp 2 stays running. Change txv for comp one adjusted txv and water flows but oil just washes out. Could problem be with comp itself or evap barrel flow or load. delta p within range and comp 2 runs. 2 is on water leaving side. 1988 chiller was told comp 2 has been changed twice in 8 years. new driers, txv ,oil. seems like liqiud washout but other comp does fine during all loads.

[wolfdog]

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[absrbrtek]

Probably an unloader sleeve has bad oring. If its not flooding back and comps loosing oil, its time to pull it apart and rebuild it.

[freonrick]

unload compressor and check oil pressure. Load each one at a time and watch the oil pressure, it should drop a little and come back up. If it drops down and stays down then you have a loader problem. I take it you have electric loaders. If so and this is the case you can leave the one that leaks unwired til it can be repaired.

[jogas]

unload compressor and check oil pressure. Load each one at a time and watch the oil pressure, it should drop a little and come back up. If it drops down and stays down then you have a loader problem. I take it you have electric loaders. If so and this is the case you can leave the one that leaks unwired til it can be repaired.

Right on.
But I've been told long term out of sequence unloading can cause problems. Trane is pretty specific on the sequence they want those cylinders to unload/load (been thru that).
Isn't there a Trane Bulletin recommending disabling one of the 3 electric unloaders to improve oil return?
jogas