Carrier 19XL - Manual (Page 165)

Charge Refrigerant into Machine
The standard 19XL machine will have the refrigerant already charged in the vessels. The
19XL may be ordered with a nitrogen holding charge of 15 psig (103 kPa). Evacuate the entire
machine, and charge machine from refrigerant cylinders.
19XL Machine Equalization without Pumpout Unit
CAUTION CAUTION
!
The transfer, addition, or removal of refrigerant in spring isolated machines may
place severe stress on external piping if springs have not been blocked in both
up and down directions.
When equalizing refrigerant pressure on the 19XL machine after service work or
during the initial machine start-up,
do not use the discharge isolation valve to
equalize . The motor cooling isolation valve or charging hose (connected between
pumpout valves on top of cooler and condenser) is to be used as the equalization
valve.
WARNING
!
WARNING