Leak Test And Evacuation; Refrigerant And Additional Oil Charge; Refrigerant Charge Determination; System Refrigerant Charge - Trane RTAA-70 Installation & Maintenance Manual

46
Installation — Remote Evaporator

Leak Test and Evacuation

After installation of the refrigerant piping, thoroughly test the system for
leaks. Pressure test the system at pressures required by local codes.
Immediately before evacuation, install the liquid line filter cores. These will be
shipped with the evaporator.
NOTE: Do not install these before the circuit is ready for evacuation, as the
cores will absorb moisture from the atmosphere.
For field evacuation, use a rotary-type vacuum pump capable of pulling a
vacuum of 100 microns or less. Follow the pump manufacturer's instructions
for proper use of the pump. The line used to connect the pump to the system
should be copper and be the largest diameter that can be practically used. A
larger line size with minimum flow resistance can significantly reduce
evacuation time.
Use the ports on the compressor suction service valves and the liquid line
shutoff valves for access to the system for evacuation. Insure that the
compressor suction service valve, the liquid line shutoff valve, the oil line
shutoff valve and any field installed valves are open in the proper position
before evacuating.
Insulate the entire suction line and the suction accumulator line. Where the
line is exposed to the weather, wrap it with weatherproof tape and seal with
weather-proof compound.
Table 8

System Refrigerant Charge

Circuit Size
35
40
50
60

Refrigerant and Additional Oil Charge

Refrigerant Charge Determination

The approximate amount of refrigerant charge required by the system must
be determined by referring to
system and checking the liquid line sightglasses.
To determine the appropriate charge, first refer to
required charge without the field-installed piping. Next, determine the charge
required for the field-installed piping by referring to
NOTE: The amounts of refrigerant listed in
pipe. Actual requirements will be in direct proportion to the actual length of
piping.
NOTE: Table 9 assumes:
Liquid Temperature = 100 F
Suction Temperature = 35 F
Suction Superheat Temperature = 4 F
The approximate amount of refrigerant is therefore the sum of the values
determined from Table 8
Lbs. of R- 22
58
61
73
98
Table 8 and must be verified by running the
Table 9
and Table 9.
Table 8 to establish the
Table 9.
are based on 100 feet of
RTAA-SVX01A-EN