Trane UCCA Installation, Operation And Maintenance Manual page 42

Coil Piping and Connections
Figure 38. Dual-circuit condensing unit: evaporator coil with four distributors
suction line
(circuit 2)
suction line
(circuit 1)
suction lines
42
thermal expansion
valves (TXV)
solenoid
valve
sight
glass
distributor
thermal expansion
valves (TXV)
sight
glass
solenoid
distributor
1. Pitch the liquid line slightly—1 inch/10 feet —so
Evaporator Coil
that the refrigerant drains toward the
with Horizontal-Split
(Standard) Circuiting evaporator.
2. Provide one expansion valve per distributor.
liquid line
(circuit 2)
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.
liquid line
4. This looks like a drain trap, but is actually due to
(circuit 1)
the requirement that the refrigerant gas leaving
the coil flows downward, past the lowest
suction-header outlet, before turning upward.
filter drier
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.
Evaporator Coil with
Intertwined Circuiting
6. Use the tube diameter recommended for a
vertical rise as specified in the condensing unit
liquid line
(circuit 2)
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
valve
evaporator.
8. Insulate the suction line.
liquid line
9. The top of the Circuit 1 suction riser must be
(circuit 1)
higher than the bottom evaporator coil. Use the
tube diameter recommended for a vertical rise
as specified in the condensing unit application
filter drier
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.
CLCH-SVX009A-EN