Carrier 69NT40-561-019, Руководство по эксплуатации и обслуживанию

Страница: 104 / 136

T-359 7–18
7.13.1 Valve Replacement
a. Removing an Expansion Valve:
NOTE
The EEV is a hermetic valve and does not have adjustable superheat (See Figure 7.10 ).
Figure 7.10 Economizer Expansion Valve
1. Pump down the compressor (refer to Section 7.3.2 ) and frontseat both suction and discharge valves.
Evacuate if unit is not equipped with service valves. Refer to Section 7.3.4 .
2. Turn unit power off and remove power from the unit.
3. Remove cushion clamps located on the inlet and outlet lines.
4. Remove insulation (Presstite) from expansion valve bulb.
5. Unstrap the bulb, located on the economizer line.
6. VALVE REMOVAL: The preferred method of removing the valve is to cut the connection between the
brazed section and the valve, using a small tube cutter. Remove valve.
Alternately, use a wet rag to keep valve cool. Heat inlet and outlet connections to valve body and
remove valve.
7. Clean the valve stem with mild cleaner, if necessary.
b. Installing an Expansion Valve:
1. The economizer valve should be wrapped in a soaked cloth for brazing. Braze inlet connection
to inlet line.
2. Braze inlet connection to inlet line.
3. Braze outlet connection to outlet line.
4. Reinstall cushion clamps on inlet and outlet lines.
c. Replace filter drier.
d. Evacuate to 500 microns by placing vacuum pump on liquid line and suction service valve.
e. Check superheat (see Section 3.2 ).
Inlet
Outlet