Trane RAUC-IOM-15, Инструкция по установке и обслуживанию, Страница: 23 / 68

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Refrigerant Piping
Refrigerant piping must be properly sized and applied.
These two factors have a very significant effect on both sys-
tem performance and reliability.
Note: Use Type “L” refrigerant grade copper tubing
only.
Refrigerant Piping should be sized and laid out according to
the job plans and specifications. This should be done when
the system components are selected
Suction Line Piping
Proper suction line sizing is required to guarantee that oil is
returned to the compressor throughout the operating sys-
tems. Furthermore, the line must be sized so that the pres-
sure drop does not excessively affect capacity or efficiency.
To accomplish both, it may be necessary to have two sizes,
one for horizontal run and vertical drops, and another for
the vertical lifts. The suction line size pre-selected in the
Table below are independent of the line length for a prop-
erly charged RAUC unit operating in a normal air condition-
ing application.
For more information, refer to the latest edition of Applica-
tion Guide SS-APG001-EN.
1. Do not use suction line traps.
2. Do not use double risers.
3. Avoid putting liquid lines underground.
4. Route suction lines as short and direct as possible.
5. Slope suction lines toward the evaporator ¼-inch to 1-
inch for every 10 feet.
6. Insulate the suction lines.
7. The suction line filter should be as close to the com-
pressor as possible.
Note: If Suction Riser Exceeds 50 Feet, Trane Must
Review The Application.
Suction Line Interconnecting Tubing
Capacity
OD Horizontal
(Per Circuit)
OD Vertical
(Per Circuit)
80 Ton 2-5/8" 2-1/8"
100 Ton 2-5/8" 2-5/8"
120 Ton 3-1/8" 2-5/8"
Note: If risers exceed 50 feet, the application
must be reviewed by Trane.
Liquid Line Piping
Liquid line sizes are based on their ability to provide a mini-
mum of 5 degrees F (2.7
o C) of sub-cooling at the expansion
valve throughout the unit’s operating envelope. Increasing
the liquid line size does not increase the available sub-cool-
ing. The uniform liquid line size, pre-selected in the Table
below, are independent of the line length or rise with in the
permissible guidelines to maintain this minimum required 5
degree F (2.7
o C) sub-cooling at the expansion valve for a
properly charged RAUC unit operating in a normal air con-
ditioning application.
The liquid line should have a slight slope in the direction of
flow so that it can be routed with the suction line.
The unit has a liquid line check valve that prevents liquid re-
frigerant from flowing backward through the liquid line, fill-
ing the condenser, and overflowing to the compressor dur-
ing the “Off” cycle. A relief valve is also installed to prevent
the build up of high pressure in the liquid line when the unit
is off. For proper operation of the relief valve, the liquid line
service valve should not be in the back seated position but
cracked open so the relief valve (and the fan pressure
switch) is open to the condenser. The line that connects the
outlet of the 235 psig relief valve to the liquid line service
valve must not be removed.
For more information, refer to the latest edition of Applica-
tion Guide SS-APG001-EN.
1. Avoid putting liquid lines underground.
2. Route liquid lines as short and direct as possible.
3. Slope liquid lines away form the condensing unit 1-inch
for every 10 feet.
4. Only insulate liquid lines that pass through heated
areas.
5. Wire solenoid valves according to the field connection
diagram for proper pump down operation.
6. The liquid line filter drier should be as close to the sole-
noid valve as possible.
Note: If The Liquid Line Riser Exceeds 10 Feet,
Trane Must Review The Application
Liquid Line Interconnecting Tubing
Capacity
OD Horizontal
(Per Circuit)
OD Vertical
(Per Circuit)
80 Ton 7/8" 7/8"
100 Ton 1-1/8" 1-1/8"
120 Ton 1-1/8" 1-1/8"
Note: If risers exceed 10 feet, the application
must be reviewed by Trane.
Installation (Continued)