Carrier 69NT40-541-306, Операция и обслуживание

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7–23 T-354
1. Pump down the unit per Section 7.4 .
2. If TXV replacement is to be performed from the front of the unit, open the upper right (EFM#1) access panel
(see Figure 3.1 ) and remove the evaporator fan motor.
3. Remove cushion clamp that secures the valve body to the bracket.
4. Unbraze the equalizer connection (1/4”), the outlet connection (5/8”), and then the inlet connection (3/8”).
See Figure 7.21 . Be careful to protect the insulation on the heaters and their wires.
5. If TXV replacement is being performed from the front of the unit, remove the access panel for the bulb.
6. Open the insulation flap. Flap is secured with Velcro (Item 3, Figure 7.22 ).
7. Loosen the thumb screw and slide the bulb, out by pulling it towards the front of the unit.
Figure 7.22 Thermostatic Expansion Valve Bulb Location
Installing the Expansion Valve
1. Braze inlet connection to inlet line (see Figure 7.21 ).
2. Braze outlet connection to outlet line.
3. Braze the equalizer connection to the equalizer line.
4. Reinstall the cushion clamp.
5. Thread the thermal bulb through the opening above the evaporator coil (see Figure 3.2 ), and slide it under
the strap and secure the thumb screw. Close the insulation flap. Reinstall bulb access panel.
6. Check superheat (refer to Section 7.14.1 ).
7.15 EVAPORATOR COIL AND HEATER ASSEMBLY
The evaporator section, including the coil, should be cleaned regularly. The preferred cleaning fluid is fresh water
or steam. Another recommended cleaner is Oakite 202 or similar, following
manufacturer's instructions.
The drain pan hose is routed behind the condenser fan motor and compressor. The drain pan line must be open to
ensure adequate drainage.
7.15.1 Evaporator Coil Replacement
1. Pump unit down (refer to Section 7.4 ).
2. With power OFF and power plug removed, remove the screws securing the panel covering the evaporator
section (upper panel).
3. Disconnect the defrost heater wiring.
4. Disconnect the defrost temperature sensor (see Figure 3.2 ) from the coil.
5. Remove middle coil support.
6. Remove the mounting hardware from the coil.
Hermetic Expansion Valve Bulb
Insulation
Insulation Flap
Velco Strip
Bulb Clamp
Thumb Screw