Expansion Valve Bulb Installation

035-18496-000-C-1102

Suitable hangers, brackets or clamps should support the refrigerant lines.

Braze all copper-to-copper joints with Silfos-5 or equivalent brazing material. Do not use soft solder.

Never braze or solder the liquid and suction lines together.

The complete suction line should be insulated with no less than ½ " Armaflex or equivalent.

If it is desirable to tape or wire the liquid and suctions lines together for support purposes, they must be completely insu- lated from each other.

EVAPORATOR SECTION PIPING

The units are shipped with a holding charge of R-22. The connections are terminated with a copper disc brazed over the ends.

Before starting installation of the mains, be sure the unit has not developed a leak in transit by connecting a pressure gauge to the service access port. If pressure still exits, the circuit may be considered leak free. If pressure does not exist, the unit must be evacuated along with the field installed refrigerant piping.

NOTE: To minimize the possibility of system failure due to dirt and moisture, a filter-drier must be installed in each liquid line as close to the evaporator as possible. Filter-driers are not supplied with the evaporator blowers. They are supplied with the matching HA/HB series condensing units.

The temperature required to make or break a brazed joint is sufficiently high to cause oxidation of the copper unless an inert atmosphere is provided.

The liquid, suction and drain connections inside the unit must be piped to the outside. Refer to 17 and 23 for unit dimen- sions or the locations and the dimensions of the access openings in the unit panel.

Remove the evaporator holding charge and any caps or discs on the liquid and suction connections that will not permit a free flow of nitrogen.

Connect a supply of dry nitrogen through a reducing regulator to an access valve or charging tail. Choose a procedure that will allow nitrogen to flow continuously through the system and reach all joints to be brazed.

Begin the refrigerant main piping by installing the liquid line from the condensing unit to the evaporator liquid connection, maintaining a flow of nitrogen during all brazing operations. The filter drier and sight glass must be located in this line, close to the evaporator. Make the suction line connection at the evaporator and run the line to the condensing unit.

After puncturing the sealing caps with a small drill bit, unbraze the condensing unit suction disc and connect the line. Maintain a flow of nitrogen through the liquid line to the evaporator, through the evaporator, back to the condensing unit and out the suction connection and service port.

NOTE: Size the suction line outside the evaporator casing per the line sizing information provided in the condensing unit instruction form 035- 18499-000.

LA300

The bulbs for the thermal expansion valve on the blower units are not factory-installed in its final location; it's only tempo- rarily taped for shipment. They must be fastened in a 4 o'clock and 8 o'clock position to the common suction line out of the evaporator coil after piping connections are made. Use the bulb clamps from the bag taped to the suction connection inside the blower unit.

LB360/LB480/LB600

The bulbs for the thermal expansion valve on the blower units are not factory-installed in its final location; it's only tempo- rarily taped for shipment. The bulbs for system one must be fastened in a 4 o'clock and 8 o'clock position to the system one suction line of system one leaving the evaporator coil after piping connections are made. Repeat the procedure for system two, locating the bulbs in a 4 o'clock and 8 o'clock position to the system two suction line. Use the bulb clamps from the bag taped to the suction connection inside the blower unit.

NOTE: Ensure the TXV bulbs are not crossed between systems. Undesirable performance and possible compressor damage may occur.

LIQUID LINE SOLENOIDS

The unit is shipped with factory installed, normally closed, liq- uid line solenoid valves. When the solenoid coil is energized with a 24-volt signal, the valve will open.

During brazing operations, the valves should be placed in the OPEN position by removing the stem cap with a 9/16” wrench, then rotating the exposed valve stem inward (CLOCKWISE), approximately 10-12 full turns (from the fully CLOSED position), using a 4” adjustable wrench.

The valve stems should be returned to the CLOSED (COUNTER-CLOCKWISE) position prior to the unit’s opera- tion. The “Pump-out” procedure is detailed in the following section.

The sequence of operation applies to the HA/HB condensing units and LA/LB air handlers when applied as a matched sys- tem. Non-matched systems will have to be field wired to oper- ate in a similar fashion as described on page 19.

NOTE: See Liquid Line Solenoid Wiring on page 22.

Unitary Products Group