Table of Contents
Advertisement
Fig. 15 — Fan Pulley Adjustments
Fig. 16 — Concentric Alignment
Fig. 17 — Fan Shaft Bearings
MAINTENANCE
Cleaning —
The unit should be thoroughly cleaned inside
and out. Frequency of cleaning will depend on unit location
and area conditions. Drains must be kept free of dirt and trash.
Coils can be cleaned with a stiff brush, vacuum cleaner, or
compressed air. Coil can be reached through access panels.
Inspection —
Check coil baffles for tight fit to prevent air
from bypassing the coil. Check panels for air leakage, particu-
larly those sealing the fan and coil compartments. Check for
loose electrical connections, oil level, proper refrigerant
charge, and refrigerant piping leaks. The fan motor and fan
shaft bearings are permanently lubricated. Further lubrication
is not required. Before start-up, be sure all service valves are
open (backseated).
Air Filters —
Air filters may be installed on the condenser
air inlet. Air filters should be replaced or cleaned on a regular
basis depending on how dirty the operating environment is.
Failure to clean air filters regularly will result in loss of unit
performance and possible nuisance tripping of the high-pres-
sure switch.
Condensate Drain —
sate drain to remove rain water, the drain pan and trap should
be cleaned at least twice per year. After cleaning, test the con-
densate drain for proper operation by pouring a bucket of water
into the condensate drain pan. The water should flow out im-
mediately and evenly.
Checking System Charge
NOTE: Condenser airflow must be properly set before
checking system charge.
50BYN units are shipped with full operating charge. If re-
charging is necessary:
1. Insert thermometer bulb in insulating rubber sleeve on
liquid line near filter drier. Use a digital thermometer for
all temperature measurements. DO NOT use a mercury
or dial-type thermometer.
2. Connect pressure gage to discharge line near compressor.
3. After unit condition have stabilized, read head pressure
on discharge line gage.
NOTE: Operate unit a minimum of 15 minutes before
checking charge.
4. From standard Pressure-Temperature charge for R-22,
find equivalent saturated condensing temperature.
5. Read liquid line temperature on thermometer; then sub-
tract from saturated condensing temperature. The differ-
ence equals subcooling temperature.
6. Compare the subcooling temperature with the normal
temperature listed in Table 5. If the measured liquid line
temperature does not agree with the required liquid line
temperature, ADD refrigerant to raise the temperature or
REMOVE refrigerant (using standard practices) to lower
the temperature (allow a tolerance of ± 3° F).
Example:
Head pressure (from gage). . . . . . . . . . . . . . . 220 psig
Saturated condensing temp (from chart) . . . . . . .108 F
Liquid line temp (from thermometer) . . . . . . . . . .96 F
Subcooling (by subtraction) . . . . . . . . . . . . . . . . . .12 F
(add charge)
21
If the unit is used with a conden-
Advertisement
Table of Contents
