IV. EVAPORATOR FAN PERFORMANCE ADJUSTMENT (Fig. 32 and 33)
Fan motor pulleys are factory set for speed shown in Table 1.
To change fan speeds:
1.Shut off unit power supply.
2.Loosen nuts on the 4 carriage bolts in the mounting base. Using adjusting bolts and plate, slide motor and remove belt.
3.Loosen
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.
See Table 24 for air quantity limits.
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.)
6.Replace and tighten belts (see Belt Tension Adjust- ment section below).
7.Restore power to unit.
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 plate.
V.BELT TENSION ADJUSTMENT
To adjust belt tension:
1.Turn off unit power.
2.Slide out fan deck to service position as shown in Evap- orator Fan Service and Replacement section above.
3.Loosen fan motor bolts.
4.Move motor mounting plate to adjust to proper belt tension. See Table 30. Motor adjuster bolts may be used to tighten belts. See Fig. 32.
5.Check for proper belt alignment. Adjust if necessary.
6.Tighten motor mounting plate bolts to lock motor in proper position.
7.Return fan deck back into operating position.
8.Restore power to unit.
Table 30 — Belt Tension Adjustment
581A |
|
| BELT TENSION (lb) |
| |
UNIT | VOLTAGE |
| Fan Type |
| |
SIZE |
|
|
|
|
|
| Low Vert | High Vert | Low Horz | High Horz | |
|
| ||||
| 230 | 4.9 | 5.1 | 4.7 | 5.0 |
210 | 460 | 4.9 | 5.1 | 4.7 | 5.0 |
| 575 | 3.9 | 5.2 | 3.8 | 4.7 |
| 230 | 5.1 | 5.6 | 5.0 | 5.5 |
240 | 460 | 5.1 | 5.6 | 5.0 | 5.5 |
| 575 | 5.1 | 5.6 | 5.0 | 5.5 |
| 230 | 5.9 | 4.5 | 5.9 | 4.5 |
300 | 460 | 5.9 | 4.5 | 5.9 | 4.5 |
| 575 | 5.9 | 4.5 | 5.9 | 4.5 |
LEGEND
Horz — Horizontal
Vert — Vertical
VI. CONDENSER-FAN ADJUSTMENT (Fig. 34)
1.Shut off unit power supply.
2.Remove
3.Adjust fan height as shown in Fig. 34.
4.Tighten setscrews and replace
5.Turn on power to unit.
| MOTOR | |
FAN | PULLEY | |
(HIDDEN) | ||
PULLEY | ||
| ||
| MOTOR | |
| MOUNTING | |
| BASE | |
| ||
| FAN DECK |