Trane CSAA User Manual

Piping and Connections
114 CLCH-SVX07K-EN
Figure 145.Typical dual-circuit condensing unit: evaporator coil with eight distributors
1. Pitch the liquid line slightly—1 inch/10 feet —so
that the refrigerant drains toward the
evaporator.
2. Provide one expansion valve per distributor.
3. Slightly pitch the outlet line from the suction
header toward the suction riser— 1 inch/10 feet
in the direction of flow. Use the tube diameter
that matches the suction-header connection.
4. This looks like a trap, but is actually due to the
requirement that the refrigerant gas leaving the
coil flows downward, past the lowest suction-
header outlet, before turning upward. Use the
double-elbow configuration to isolate the TXV
bulb from other suction headers.
5. Use the “horizontal” tube diameter as specified
in the condensing unit application manual.
6. Use the tube diameter recommended for a
vertical rise as specified in the condensing unit
application manual. Ensure that the top of the
riser is higher than the evaporator coil.
7. Pitch the suction line slightly—1 inch/10 feet —
so that the refrigerant drains toward the
evaporator.
8. Insulate the suction line.
9. The top of the Circuit 1 suction riser must be
higher than the bottom evaporator coil. Use the
tube diameter recommended for a vertical rise
as specified in the condensing unit application
manual.
10. The top of the Circuit 2 suction riser must be
higher than the top evaporator coil. Use the tube
diameter recommended for a vertical rise as
specified in the condensing unit application
manual.
11. Only use a “trim” solenoid valve for constant-
volume, humidity-sensitive applications. For all
other applications, install a single solenoid
valve (the “pumpdown” solenoid valve)
between the liquid-line filter drier and the sight
glass.
Note: Due to reduced coil volume in condensing
units with microchannel heat exchanger
condenser, do not use trim solenoid valves
for these units.
Liquid line
(Circuit 1)
Thermal expansion
valves (TXV)
Distributor
“Trim”
solenoid valve
Thermal expansion
valves (TXV)
Distributor
(Circuit 1)
(Circuit 2)
Filter drier
Liquid line
(Circuit 2)
Sight
glass
“Pump-down”
solenoid valve
Suction line
(Circuit 1)
(Circuit 2)
Suction line
Liquid line
(Circuit 1)
Filter drier
Liquid line
(Circuit 2)
Sight
glass
“Trim”
solenoid valve
“Pump-down”
solenoid valve
Suction lines
Evaporator Coil
with Horizontal-Split (Standard) Circuiting
Evaporator Coil with Intertwined Circuiting

Trane CSAA Specifications

General

Brand	Trane
Model	CSAA
Category	Air Handlers
Language	English