Carrier 19XL - Manual (Page 181)

Extended Shutdown
The refrigerant should be transferred into the storage vessel (if supplied; see Pumpout and
Refrigerant Transfer Procedures ) in order to reduce machine pressure and possibility of leaks.
Maintain a holding charge of 5 to 10 lbs (2.27 to 4.5 kg) of refrigerant to prevent air from leaking
into the machine.
If freezing temperatures are likely to occur in the machine area, drain the chilled water,
condenser water, and the pumpout condenser water circuits to avoid freeze-up. Keep the
waterbox drains open.
Leave the oil charge in the machine with the oil heater and controls energized to maintain the
minimum oil reservoir temperature.
After Extended Shutdown
Be sure that the water system drains are closed. It may be advisable to flush the water
circuits to remove any soft rust which may have formed. This is a good time to brush the tubes if
necessary.
Check the cooler pressure on the LID default screen, and compare to the original holding
charge that was left in the machine. If (after adjusting for ambient temperature changes) any
loss in pressure is indicated, check for refrigerant leaks. See Check Machine Tightness section.
Recharge the machine by transferring refrigerant from the storage tank (if supplied). Follow
the Pumpout and Refrigerant Transfer Procedures section. Observe freeze-up precautions.