Trane RTAC 140-400 ton units (50 HZ) User Manual

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RTAC-SVX01F-EN
57
Installation - Mechanical 
 
Remote Evaporator Option
Suction Accumulator Sizing
Use 
 to calculate length and size of the required suction accumulator(s).
Example of Suction Accumulator Line Sizing
Use 
 and the same assumptions from the liquid line sizing example to calcu-
late the suction accumulator line size and length.
In this case the accumulator is installed at the evaporator.
1.
Use the 70 ton circuit column.
2.
From the liquid line sizing example, use a field installed liquid line of: 
 
1.375 (1 3/8”) inches
3.
The actual feet of liquid line installed is: 117 feet
4.
The size of the suction accumulator is: 3 5/8 inches
5.
The length of the suction line accumulator is: 59 feet
Piping Installation Procedures
The outdoor unit and the evaporator are shipped with a 25 psig holding pressure of 
dry nitrogen. Do not relieve this pressure until field installation of the refrigerant pip-
ing is to be accomplished. This will require the removal of the temporary pipe caps.
NOTE:
Use Type L refrigerant-grade copper tubing only.
The refrigerant lines must be isolated to prevent line vibration from being transferred 
to the building. Do not secure the lines rigidly to the building at any point.
All horizontal suction lines should be pitched downward, in the direction of flow, at a 
slope of 1/2 inch per 10 feet of run. 
Do not use a saw to remove end caps, as this may allow copper chips to contaminate 
the system. Use a tubing cutter or heat to remove the end caps.
When sweating copper joints, flow dry nitrogen through the system. This prevents 
scale formation and the possible formation of an explosive mixture of R-134a and air. 
This will also prevent the formation of toxic phosgene gas, which occurs when refrig-
erant is exposed to open flame.
 WARNING
Hazardous Gas!
To prevent injury or death, due to explosion and/or inhalation of 
phosgene gas, purge the system thoroughly with dry nitrogen while 
sweating connections. Use a pressure regulator in the line between the 
unit and the high pressure nitrogen cylinder to avoid over-pressurization 
and possible explosion.Failure to use a nitrogen purge and pressure 
regulator could result in death or serious injury or equipment damage.