Carrier PC211 Start-Up, Operation And Maintenance Instructions Manual page 184

Pumpout and Refrigerant Transfer Procedures
Preparation
The 19XL may come equipped with an optional storage tank or pumpout system, or a
pumpout compressor. The refrigerant can be pumped for service work to either the cooler/
compressor vessel, or the condenser vessel by using the optional pumpout system. If a storage
tank is supplied, the refrigerant can be isolated in the external tank. The following procedures
are used to describe how to transfer refrigerant from vessel to vessel and perform machine
evacuations.
Operating the Optional Pumpout Compressor
1. Be sure that the suction and the discharge service valves on the optional pumpout
compressor are open (backseated) during operation. Rotate the valve stem fully
counterclockwise to open. Frontseating the valve closes the refrigerant line and opens the
gage port to compressor pressure.
2. Make sure that the compressor holddown bolts have been loosened to allow free spring
travel.
3. Open the refrigerant inlet valve on the pumpout compressor.
4. Oil should be visible in the compressor sight glass under all operating conditions and during
shutdown. If oil is low, add oil as described under
section. The pumpout unit control wiring schematic is detailed in
Optional Pumpout System Maintenance
Figure 36.