47
Blower Wheel Removal and Re-installation (see
Fig. 32)
Refer to Fig. 28 for 40UH200 units only, Fig. 29 for 40UV050-
150 and 40UH075-125 units with PSC motors, Fig. 30 for
40UV050-125 and 40UH075-150 units with ECM motors.
To remove blower wheel:
1. Turn off all power to the unit.
2. Remove blower section per service instructions in
Blower Assembly Section Removal and Re-installation.
3. Use
5
/
32
-in. hex tool to loosen setscrews on all blower
wheels (two per wheel).
4. Loosen inboard/center bearing setscrews (only on
40UV,UH150 and 200 size units).
5. If unit has ECM motor, remove motor shroud (sheet
metal cover — Fig. 28, Item 6; Fig. 30, Item 4) by
removing two
5
/
16
-in. hex nuts.
Do not discard cooling
shroud.
6. Loosen
5
/
16
-in. motor mount (Fig. 28, Item 7; Fig. 29,
Item 2; Fig. 30, Item 2), nut (Fig. 28, Item 3; Fig. 29,
Item 5; Fig. 30, Item 6), and bolt (Fig. 28, Item 4; Fig.
29, Item 4; Fig. 30, Item 5), until motor housing (Fig. 28,
Item 5; Fig. 29, Item 3; Fig. 30, Item 3) moves freely.
7. Slide shaft-coupling-motor assembly (Fig. 26, Items 3, 2,
1; Fig. 28, Items 5, 2, 10) out of wheels and unit until
shaft clears inboard/center bearing assembly (30-in.
maximum clearance required from edge of frame end).
8. Remove four
1
/
4
-in. head screws (Fig. 32, Item 6) securing
blower housing(s) (Fig. 32, Item 7) to blower deck
(Fig. 32, Item 3) and remove blower and wheel assembly.
9. Remove five
1
/
4
-in. head screws (Fig. 32, Item 5) secur-
ing blower inlet ring (Fig. 32, Item 4) to blower housing
and remove inlet ring.
10. Remove blower wheel(s) (Fig. 32, Item 8).
To re-install blower wheel:
1. Install new blower wheel(s) (Fig. 32, Item 8). Ensure that
the fan blades are installed in the correct orientation (cup
of blade towards discharge).
2. Install inlet ring (Fig. 32, Item 4) and install five ¼-in.
head screws (Fig. 32, Item 5) securing blower inlet ring
to blower housing (Fig. 32, Item 7).
3. Install four
1
/
4
-in. head screws (Fig. 32, Item 6) securing
blower housing(s) (Fig. 32, Item 7) to blower deck
(Fig. 32, Item 3).
4. Slide shaft-coupling-motor assembly (Fig. 26, Items 3, 2,
1; Fig. 28, Items 5, 2, 10) back into bearing and wheels.
Do not use excessive force. Damage to wheels may
occur.
5. Insert shaft-coupling-motor assembly into wheels until
motor clearance is as specified for motor type (PSC or
ECM). See Fig. 31 or Fig. 24.
6. Ensure that motor shaft is perpendicular to motor blower
endplate. Tighten
5
/
16
-in. motor mount (Fig. 28, Item 7;
Fig. 29, Item 2; Fig. 30, Item 2), nut (Fig. 28, Item 3;
Fig. 29, Item 5; Fig. 30, Item 6), and bolt (Fig. 28, Item
4; Fig. 29, Item 4; Fig. 30, Item 5), until motor (Fig. 28,
Item 5; Fig. 29, Item 3; Fig. 30, Item 3) is secure.
7. Install motor shroud (sheet metal cover — Fig. 28, Item
6; Fig. 30, Item 4) using two
5
/
16
-in. hex nuts if using
ECM motor. Align “window” with receptacles on motor.
Motor control module could overheat and fail if oper-
ated without cooling shroud.
8. Re-install blower section into frame assembly. See
Fig. 25.
9. Tighten the four
5
/
16
-in. nuts retaining blower section to
frame.
10. Tighten the two
5
/
16
-in. (Fig. 26, Item 6) nuts retaining
the inboard bearing bracket to the pipe chase (only on
40UV,UH150 and 200 size units).
11. Re-install two carriage bolts (Fig. 25, Item 6) that attach
the front brace to the frame sides.
12. Re-attach green ground wire that connects the motor to
the frame with
1
/
4
-in. head screw if unit has a PSC motor.
The ECM motors are grounded through the harness.
13. Re-attach wiring harness connector(s) to motor.
14. Center each wheel in its respective housing and tighten
wheel setscrews (two for each wheel).
15. Re-install one
1
/
4
-in. head screw (Fig. 25, Item 1) at cen-
ter of blower deck attaching blower deck to pipe chase.
16. Re-install the four
1
/
4
-in. head screws (Fig. 25, Item 2)
holding the blower section sides to the coil section sides.
17. Rotate the fan shaft by hand to ensure that fans are
unrestricted and can rotate freely. Check for any fan
obstructions.
18. Remove lockout and operate unit for approximately
60 seconds to let inboard/center bearing mount self-
adjust (only on 40UV,UH150 and 200 size units).
19. Lock out and tag all power supplies to equipment and
controls. Tighten the two bearing setscrews (only on
40UV,UH150 and 200 size units). See Fig. 26, 28 or 32.
20. Re-install the coil baffle using the six
1
/
4
-in. head screws
that attach the coil baffle to the coil section. See Item 4 in
21. Re-install
1
/
4
-in. head screws along length of unit secur-
ing coil baffle to the blower section. See Item 5 in
Fig. 25.
22. Re-install optional vanes and screens and install top
panel (40UV). re-install top (40UV) or front (40UH) dis-
charge plenum and ductwork if required or discharge
grille.
23. Re-install front (40UV) or bottom (40UH) panels. re-
install end panels.
Ensure that tag on each right front
panel (40UV) or middle bottom panel (40UH)
matches unit tag.
24. Restore power to unit.
WARNING
Lock out and tag all power supplies to equipment and con-
trols prior to servicing unit. Follow all safety codes. Failure
to do so could result in personal injury.
CAUTION
The assembly order of the bearing installation is critical. Be
careful with all components during removal and installa-
tion. Any excessive force applied to these components can
cause unintended damage and void unit warranty.
IMPORTANT: Tag each right front panel (40UV) or
middle bottom panel (40UH) for each unit. Panels have
electrical information specific to each unit.
