Carrier 48MPD, MPE62L-10R, 50MP62L-10R Lubrication, Refrigerant Circuit, Manufacturer Lubricant

MAIN BURNERS (48MP Only) Ð At the beginning of each heating season, inspect for deterioration or blockage due to corrosion or other causes. Observe the main burner ¯ames. Refer to Main Burners section on page 52.

FLUE GAS PASSAGEWAYS (48MP Only) Ð The ¯ue col- lector box and heat exchanger cells may be inspected by re- moving heat exchanger access panel (Fig. 3 and 4), ¯ue box cover, and main burner assembly (Fig. 52). Refer to Main Burners section on page 52 for burner removal sequence. If cleaning is required, remove heat exchanger baffles and clean tubes with a wire brush.

Use caution with ceramic heat exchanger baffles. When installing retaining clip, be sure the center leg of the clip extends inward toward baffle. See Fig. 53.

COMBUSTION-AIR BLOWERS (48MP Only) Ð Clean pe- riodically to assure proper air¯ow and heating efficiency. In- spect blower wheel every fall and periodically during heat- ing season. For the ®rst heating season, inspect blower wheel bi-monthly to determine proper cleaning frequency.

To inspect blower wheel, remove heat exchanger access panel. Shine a ¯ashlight into opening to inspect wheel. If cleaning is required, remove motor and wheel assembly by removing screws holding motor mounting plate to top of com- bustion fan housing (Fig. 54). The motor and wheel assem- bly will slide up and out of the fan housing. Remove the blower wheel from the motor shaft and clean with a deter- gent or solvent. Replace motor and wheel assembly.

Lubrication

COMPRESSORS Ð Each compressor is correctly charged at the factory. Refer to 06E Compressor Service Manuals if additional information regarding compressor lubrication sys- tem is required. See Compressor Oil section on page 29 and Table 3.

FAN SHAFT BEARINGS Ð Lubricate fan shaft bearings at least once a year with suitable bearing grease. Extended grease lines are provided on pulley side of blower. Typical lubri- cants are given below:

MANUFACTURER	LUBRICANT
Texaco	Regal AFB-2*
Mobil	Mobilplex EP No. 1
Sunoco	Prestige 42
Texaco	Multifak 2

*Preferred lubricant because it contains rust and oxidation inhibitors.

FAN MOTOR BEARINGS Ð The condenser- and evaporator- fan motors have sealed bearings so no ®eld lubrication is required.

DOOR HINGES Ð All door hinges should be lubricated at least once a year.

Coil Cleaning Ð Clean the coils with a vacuum cleaner, compressed air, water, or a non-wire bristle brush.

Refrigerant Circuit

LEAK TESTING Ð Units are shipped with a full operating charge of R-22 (see Table 1). If there is no pressure in the system, introduce enough nitrogen to search for the leak. Repair the leak using good refrigeration practices. After leaks are repaired, system must be evacuated and dehydrated using methods described in GTAC II, Module 4, System Dehydration.

REFRIGERANT CHARGE (Refer to Table 1) Ð At the liq- uid line connection point on each circuit is a factory- installed liquid line service valve. On each valve is a 1¤4-in. Schrader connection for charging liquid refrigerant.

All units are shipped with a complete operating charge of R-22. See unit nameplate and Table 1 for amount of charge. When adding a complete charge, evacuate system using stand- ard evacuating procedures and weigh in the speci®ed amount of charge. All units have charging charts for each refrigerant circuit. See Fig. 55-59.

Fig. 52 Ð Burner Section Detail

CERAMIC

BAFFLE

CLIP

HEAT EXCHANGER

TUBES

NOTE: One baffle and clip wll be in each upper tube of the heat exchanger.

Fig. 53 Ð Removing Heat Exchanger Ceramic

Baffles and Clips

Fig. 54 Ð Combustion Blower Removal

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