COMBUSTION-AIR BLOWERS (48N ONLY)
Clean periodically to assure proper airflow and heating effi- ciency. Inspect blower wheel every fall and periodically during heating season. For the first heating season, inspect blower wheel bi-monthly to determine proper cleaning frequency.
To inspect blower wheel:
RETURN FAN MOTOR PLATE
Adjust using a wrench on the adjusting bolts:
BELT INSTALLATION AND TENSIONING
IMPORTANT: When installing or replacing belts, always use a complete set of new, matched belts to prevent potential vibration problems. Mixing belts often results in premature breakage of the new belts.
For proper belt life, the motor and fan pulleys must be properly aligned. To check, first turn off unit power. Place a straightedge against the motor and fan pulleys. See Fig. 52. If the pulleys are properly aligned, the straightedge should be parallel to the belts.
If they are not parallel, check that the motor shaft and fan shaft are parallel. If they are not, adjust the motor plate adjusting bolts until they are.
After verifying that the shafts are parallel, loosen the setscrews on the motor pulley. Move pulley on the shaft until the pulleys are parallel. To move the sheave on the shaft, loosen the belts. If necessary, blower sheave can also be moved on the shaft.
INSTALLING REPLACEMENT MOTOR PULLEY
To install a field-supplied replacement pulley:
CONDENSER FAN ADJUSTMENT (METAL FANS)
CONDENSER FAN ADJUSTMENT (PLASTIC FANS)
Each fan is supported by a formed wire mount bolted to a fan deck and covered with a wire guard. The exposed end of the fan motor shaft is protected from weather by grease. If the fan motor must be removed for service or replacement, be sure to regrease fan shaft and reinstall fan cover, retaining clips, and fan guard. For proper performance, the fans should be positioned as shown in Fig. 54. Tighten setscrews to 14 1 ft-lb (18 1.3 N-m).
Check for proper rotation of the fan(s) once reinstalled (counterclockwise viewed from above). If necessary to reverse, switch leads at contactor(s) in control box.
AIR PRESSURE TRANSDUCER FIELD ADJUSTMENT
All transducers have been factory calibrated and should not re- quire field adjustment. If field adjustment is necessary, follow the instructions below.
Inspect unit at the beginning of each heating and cooling season and during each season as operating conditions may require.
MICROCHANNEL HEAT EXCHANGER (MCHX) CONDENSER COIL MAINTENANCE AND CLEANING RECOMMENDATIONS
Do not apply any chemical cleaners to MCHX condenser coils. These cleaners can accelerate corrosion and damage the coils.
Routine cleaning of coil surfaces is essential to maintain proper operation of the unit. Elimination of contamination and removal of harmful residues will greatly increase the life of the coil and extend the life of the unit.
The following steps should be taken to clean MCHX condenser coils:
Excessive water pressure will fracture the braze between air centers and refrigerant tubes.
Clean or replace at start of each heating and cooling season or more often if operating conditions require. Refer to Installation Instructions for type and size.
OUTDOOR-AIR INLET SCREENS
Source: MaintainX (Community Member)