My old York R-11(converted to 123) Seems happiest when operating with 65-70 condensor water temps. We have had no problems with oil migration, but occasionally the oil will foam a few minutes after startup when the equalizing valve first opens.
At first, some operators were thinking we had oil migration and the sump was too low.
To remedy the oil foaming problem, we programed it to startup @ 45% FLA and remain there for 30 minutes, then allow it to increase load in 10% increments as required to satisfy LCW setpoint. Running the chiller for long below 45% will tend to overheat the compressor....Allowing it to assume the load too fast will cause the oil to foam instantly when the EQ/vent valve opens.
If you ask the question because chiller is shutting down after start up due to low oil pressure, then do a cold start in service mode and limit FLA to 45%......Once you hear the EQ/vent valve open(3-5 minutes after startup), observe sump sightglass and oil pressure....You may see some foaming and hear the pump chatter and pressure may drop...After a 10-15 minutes if pump has stopped chattering, pressure increased to normal and oil stopped foaming, then bump it up 10% at a time until you can release it in automatic.
