Bryant 580F Ix. - Adjust Evaporator-Fanspeed, A. Direct-DriveMotors, B. Belt-DriveMotors

IX. STEP 9 — ADJUST EVAPORATOR-FAN SPEED

Adjust evaporator-fan rpm to meet jobsite conditions. Table 8 shows fan rpm at motor pulley settings. Table 9 shows motor performance. Refer to Tables 10-33 to determine fan speed settings.

A. Direct-Drive Motors

The evaporator-fan motor factory speed setting is shown on label diagram affixed to base unit. If other than factory set- ting is desired, refer to label diagram for motor reconnection. See Fig. 33 for direct drive motor location.

B. Belt-Drive Motors

Fan motor pulleys are factory set for speed shown in Table 1. See Fig. 34 for belt drive motor location.

NOTE: Before adjusting fan speed, make sure the new fan speed will provide an air temperature rise range as shown in Table 1.

To change fan speed:

1.Shut off unit power supply and tag disconnect.

2.Loosen belt by loosening fan motor mounting nuts. See Fig. 34.

3.Loosen movable pulley flange setscrew (see Fig. 35).

4.Screw movable flange toward fixed flange to increase speed and away from fixed flange to decrease speed. Increasing fan speed increases load on motor. Do not exceed maximum speed specified in Table 1.

5.Set movable flange at nearest keyway of pulley hub and tighten setscrew. (See Table 1 for speed change for each full turn of pulley flange.)

To align fan and motor pulleys:

1.Loosen fan pulley setscrews.

2.Slide fan pulley along fan shaft.

3.Make angular alignment by loosening motor from mounting.

To adjust belt tension:

1.Loosen fan motor mounting nuts.

2.Slide motor mounting plate away from fan scroll for proper belt tension (1/2-in. deflection with 8 to 10 lb of force).

3.Tighten motor mounting nuts.

4.Adjust bolt and tighten nut to secure motor in fixed position.

Fig. 33 — Direct-Drive Motor Mounting

MOTOR MOUNTING

PLATE NUTS

Fig. 34 — Belt Drive Motor Mounting

Fig. 35 — Evaporator-Fan Pulley Adjustment

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