Carrier 48TJ016-028 - Manual (Page 42)

9. Slide out the motor and motor mounting plate.
10. Disconnect wiring connections and remove the 4 mount­
ing bolts.
11. Remove tlie motor.
12. To instiill the new motor, reverse Steps 1-11.
Belt Tension Adjustment — To adjust belt tension:
1. Loosen fan motor bolts.
2. a Size 016 Units:
Move motor mounting plate up or down for proper
belt tension
('/2 in. deflection with one finger),
b. Size 020-028 Units:
Turn motor jacking bolt to move motor mounting
plate up or down for proper belt tension (^/g in.
deflection at midspan with one finger [9 lb force]).
3. Tighten nuts,
4. Adjust bolts and nut on mounting plate to secure motor in
fixed position.
Condenser-Fan Adjustment
48TJ01 6,020 UNITS (Fig. 5.3)
1. Shut off unit power supply.
2. Remove access panel(s) closest to the fan to be adjusted.
3. Loosen fan hub setscrews.
4. Adjust fan height on shaft using a straightedge placed
across the fan orifice.
5. Tighten setscrews and replace panel(s).
6 . Turn on unit power.
48TJ024,028 UNITS (Fig. 54)
1. Shut off unit power supply.
2. Remove fan top-grille assembly and loosen fan hub
screws.
3. Adjust fan height on unit, using a straightedge placed
across the fan orifice.
4. Tighten setscrews and replace mbber hubcap to prevent
hub from rusting to motor shaft,
5. Fill hub recess witli permagum if mbber hubcap is
missing.
Powor Failuro — Dampers have a spring return. In event
of power failure, dampers will return to fully closed position
until power is restored. Do not manually operate economiz,er
motor.
Refrigerant Charge — Amount of refrigerant chiu-ge is
listed on unit nameplate and in Table 1. Refer to Carrier
NOTE: Dimensions are in inches.
Fig. 53 — Condenser Fan Adjustment, 48TJ016,020
GTAC II; Module 5; Charging, Recoveiy, Recycling, and
Reclamation section for chiu'ging methods and procedures.
Unit panels must be in place when unit is operating during
chiU'ging procedure.
NOTE: Do not use recycled refrigerant as it may contain
contaminants.
NO CHARGE — Use standard evacuating techniques. After
evacuating system, weigh in the specified amount of refriger­
ant (refer to Table 1).
LOW CHARGE COOLING — Using cooling charging chart
(see Fig. 55), add or remove refrigerant until conditions of the
chaif are met. Note that chtu'ging chtuf is different from those
nonnally used. An accurate pressure gage and temperature­
sensing device is required. Charging is accomplished by ensur­
ing the proper amount of liquid sub-cooling. Measure liquid
line pressure at the liquid line service valve using pressure
gage. Connect temperature sensing device to the liquid line
neitr the liquid line service valve and insulate it so tliat outdoor
ambient temperature does not affect reading.
TO USE THE COOLING CHARGING CHART — Use the
above temperature and pressure readings, and find the intersec­
tion point on the cooling charging chart. If intersection point
on chart is above line, add refrigerant. If intersection point on
chiu't is below line, carefully recover some of the charge.
Recheck suction pressure as charge is adjusted.
NOTE: Indoor-air cfm must be within normal operating range
of unit. All outdoor fans must be operating.
Tlie TXV (thermostatic expansion valve) is set to maintain
between 15 and 20 degrees of superheat at the compressors.
The valves are factory set and should not require re-adjustment,
MOISTUREMISERTM SYSTEM CHARGING —- The sys­
tem charge for units with the MoistureMi$er option is greater
than that of the standard unit iilone. Tlie chtuge for units with
this option is indicated on the unit nameplate drawing. To
chaige systems using the MoistureMi$er dehumidification
package, fully evacuate, recover, and re-chtuge the system to
the nameplate specified charge level. To check or adjust
refrigerant charge on systems using the MoistureMi$er dehu­
midification package, chaige per the standard subcooling
chiu'ts. The subcooler MUST be deenergized to use the charg­
ing chiufs. The charts reference a liquid pressure (psig) and
temperature at a point between the condenser coil and the sub­
cooler coil. A tap is provided on the unit to measure liquid
pressure entering the subcooler (leaving tlie condenser).
BOTH CIRCUITS
ALL OUTDOOR FANS MUST BE OPERATING
Fig. 55 — Cooling Charging Chart
Fig. 54 — Condenser-Fan Adjustment, 48TJ024,028
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