—36—
5. Remove the belt drive.
6. Remove jacking bolt and tapped jacking bolt plate.
7. Remove the 2 screws that secure the motor mounting
plate to the motor support channel.
8. Remove the 3 screws from the end of the motor sup-
port channel that interfere with the motor slide path.
9. Slide out the motor and motor mounting plate.
10. Disconnect wiring connections and remove the
4 mounting bolts.
11. Remove the motor.
12. To install the new motor, reverse Steps 1-11.
V. BELT TENSION ADJUSTMENT
To adjust belt tension:
1. Loosen fan motor bolts.
2. Turn motor jacking bolt to move motor mounting
plate up or down for proper belt tension (
3
/
8
in. deflec-
tion 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.
VI. CONDENSER-FAN ADJUSTMENT
A. 580F180, 210, 300 UNITS (Fig. 40)
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.
B. 580F240 Units (Fig. 41)
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 rubber hubcap to pre-
vent hub from rusting to motor shaft.
5. Fill hub recess with permagum if rubber hubcap is
missing.
VII. POWER FAILURE
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 economizer motor.
VIII. REFRIGERANT CHARGE
Amount of refrigerant charge is listed on unit nameplate and
in Table 1. Refer to GTAC II; Module 5; Charging, Recovery,
Recycling, and Reclamation section for charging methods
and procedures. Unit panels must be in place when unit is
operating during charging procedure.
NOTE: Do not use recycled refrigerant as it may contain
contaminants.
A. No Charge
Use standard evacuating techniques. After evacuating sys-
tem, weigh in the specified amount of refrigerant (refer to
Table 1).
B. Low Charge Cooling
Using cooling charging chart (see Fig. 42), add or remove
refrigerant until conditions of the chart are met. Note that
charging chart is different from those normally used. An
accurate pressure gage and temperature-sensing device is
required. Charging is accomplished by ensuring the proper
amount of liquid subcooling. Measure liquid line pressure at
the liquid line service valve using pressure gage. Connect
temperature sensing device to the liquid line near the liquid
line service valve and insulate it so that outdoor ambient
temperature does not affect reading.
Fig. 38 — Evaporator-Fan Pulley and Adjustment
NOTE: A 3
1
/
2
-in. bolt and threaded plate are included in the installer’s
packet. They should be added to the motor support channel below the
motor mounting plate to aid in raising the motor. The plate part number
is 50DP503842. The adjustment bolt is
3
/
8
-16 x 1
3
/
4
-in. LG.
Fig. 39 — 580F180-300 Evaporator-Fan Motor Section
