Carrier 17/19EX - Manual (Page 252)

Oil should be visible in the compressor sight glass both during operation and at shutdown.
Always check the oil level before operating the compressor. Before adding or changing oil,
relieve the refrigerant pressure as follows:
1. Attach a pressure gage to the gage port of either compressor service valve ( Figure 34 ).
2. Close the suction service valve and open the discharge line to the storage tank or the
machine.
3. Operate the compressor until the crankcase pressure drops to 2 psig (13 kPa).
4. Stop the compressor and isolate the system by closing the discharge service valve.
5. Slowly remove the oil return line connection ( Figure 33 ). Add oil as required.
6. Replace the connection and reopen the compressor service valves.
Pumpout Safety Control Settings ( Figure 47 )
The pumpout system high-pressure switch should open at 161 psig (1110 kPa) and closes at
130 psig (896 kPa). Check the switch setting by operating the pumpout compressor and slowly
throttling the pumpout condenser water.
Click here for Figure 47 — Controls for Optional Pumpout Compressor