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CU MANUAL
IOM-14
12 of 46
Feb 06 R4
Hot Gas Solenoid Valves (Required When Equipped With A Hot Gas Bypass Valve)
Whenever a system is equipped with hot gas bypass valve, a hot gas solenoid valve is required. The valve
will open and close with the liquid line solenoid valve. The hot gas bypass solenoid valve must be installed
at the condensing unit, close to the discharge line tee.
NOTE:
Liquid line solenoid valves must be installed at the evaporator coil, close to the TX valve.
Hot gas solenoid valves must be installed at the condensing unit, close to the discharge line
tee.
Thermostatic Expansion Valve (TX Valve) (Required)
The thermostatic expansion valve is sized to match the capacity of the system. The
TX valve should be balanced or dual ported and must be externally equalized. One
valve is required per distributor. The equalization tube connects to the suction line
at the outlet of the evaporator downstream of the bulb. The TX valve sensing bulb
is installed at the same location tightly strapped to the suction line. Suggested
positioning is at the 4:00 o’clock or 8:00 o’clock position. It is good practice to insulate the TX bulb after
installation.
EngA Intercooler (Optional)
The EngA Intercooler is a small liquid heat exchanger installed
between the TX valve and the distributor. The heat exchanger
provides, “just in time”, subcooling to liquid refrigerant
entering the TX valve. This adds stability to systems that
experience occasional flashing in the liquid line.
TX VALVE
UPFL OW DISTRI BUTOR
SIGHT GLASS
(OPTIONAL)
LIQUID OU T
LIQUID LIN E
SIGHT GLASS
(OPTIONAL)
HOT GAS BY PASS
CONNECTION
(OPTIONAL)
LIQUID I N
