Step 9 - Adjust Evaporator-Fan Speed; Direct Drive Motors; Belt Drive Motors - Carrier 48TJE Series Installation, Start-Up And Service Instructions Manual

Fig. 31 — PARABLADE Economizer Barometric
Relief Damper Characteristics
Step 9 — Adjust Evaporator-Fan Speed —
evaporator-fan speed to meet jobsite conditions. Table 3 shows
fan rpm at motor pulley settings. Table 4 shows motor
performance. Refer to Tables 5-18 to determine fan speed
settings.
DIRECT DRIVE MOTORS — The evaporator-fan motor fac-
tory speed setting is shown on label diagram affixed to base
Fig. 32 — Direct Drive Motor Mounting
unit. If other than factory setting is desired, refer to label
diagram for motor reconnection. See Fig. 32 for direct drive
motor location.
BELT DRIVE MOTORS — Fan motor pulleys are factory
set for speed shown in Table 1. See Fig. 33 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.
2. Loosen belt by loosening fan motor mounting nuts. See
Fig. 33.
3. Loosen movable pulley flange setscrew (see Fig. 34).
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 maxi-
mum 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.)
Adjust
Fig. 33 — Belt Drive Motor Mounting
Fig. 34 — Evaporator-Fan Pulley Adjustment
18
MOTOR MOUNTING
NUTS AND BOLTS