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4
Fig. 4 —
Belt Drive Motor Mounting
Belt
Check the belt condition and tension quarterly. Inspect the belt for
signs of cracking, fraying or glazing along the inside surfaces.
Check belt tension by using a spring-force tool (such as Brown
-
ing’s “Belt Tension Checker” (P/N 1302546 or equivalent tool);
tension should be 6 lb at a
5
/
8
-in. (1.6 cm) deflection when mea
-
sured at the centerline of the belt span. This point is at the center of
the belt when measuring the distance between the motor shaft and
the blower shaft.
NOTE: Without the spring-tension tool, place a straightedge
across the belt surface at the pulleys, then push down on the belt at
mid-span using one finger until a
1
/
2
-in. (1.3 cm) deflection is
reached. See Fig. 5.
Adjust belt tension by loosening the motor mounting plate
front and rear bolts and sliding the plate toward the fan (to re
-
duce tension) or away from fan (to increase tension). Ensure
the blower shaft and the motor shaft are parallel to each other
(pulleys aligned). When finished, tighten all bolts and torque to
65 to 70 in.-lb (7.4 to 7.9 Nm).
Fig. 5 —
Checking Blower Motor Belt Tension
REPLACING THE V-BELT
NOTE: Use a belt with the same section type or similar size. Do
not substitute a FHP-type (cogged) belt. When installing the new
belt, do not use a screwdriver or pry-bar to force the belt over the
pulley flanges, this will stress the belt and cause a reduction in belt
life. Damage to the pulley can also occur.
1. Loosen the four front and rear motor mounting plate bolts
(see Fig. 6).
2. Loosen the two jack bolt jam nuts.
3. Turn the two jack bolts counterclockwise to loosen bringing
the motor closer to the blower.
4. Remove the belt by gently lifting the old belt over one of the
pulleys.
5. Install the new belt by gently sliding the belt over both pul
-
leys. and then sliding the motor and plate away from the fan
housing until proper tension is achieved.
6. Turn the jack bolts clockwise to increase the tension of the V-
belt.
7. Adjust the V-belt tension using Browning’s “Belt Tension
Checker” (P/N 1302546 or equivalent tool) to 6 lb at a
5
/
8
-in.
(1.6 cm) deflection when measured at the centerline of the
belt span. The tension can also be checked depressing the belt
at mid-span with one finger until a ½-in (1.3 cm) deflection is
reached.
8. Check alignment of the pulleys, adjust the motor mounting
base as needed. Tighten four motor mounting bolts. Torque
all bolts to 65 to 70 in.-lb (7.4 to 7.9 Nm).
9. Tighten two jack bolt jam nuts. Torque jam nuts to 65 to
70 in.-lb (7.4 to 7.9 Nm).
10. Check the tension after a few hours of runtime and re-adjust
as required.
Fig. 6 —
Replacing the V-Belt
Adjustable-Pitch Pulley on Motor
The motor pulley is an adjustable-pitch type that allows a servicer
to implement changes in the fan wheel speed to match previously
installed ductwork systems. The pulley consists of a fixed flange
side that faces the motor (secured to the motor shaft) and a mov
-
able flange side that can be rotated around the fixed flange side
that increases or reduces the pitch diameter of this driver pulley.
See Fig. 7.
BROWNING BELT
TENSION CHECKER
STRAIGHTEDGE
1/2”
(1.3 cm)
BELT
DEFLECTION
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature wear
and damage to equipment.
Do not use a screwdriver or a pry bar to place the new V-belt in
the pulley groove. This can cause stress on the V-belt and the
pulley resulting in premature wear on the V-belt and damage
to the pulley.
BLOWER PULLEY
V-BELT
MOTOR PULLEY
MOTOR
MOTOR MOUNTING
BRACKET BOLTS (4)
MOTOR MOUNTING
BRACKET (2)
JACK BOLT JAM NUT (2)
JACK BOLT (2)
Summary of Contents for WeatherMaker 50TCQ 17-24 Series
Page 35: ...35 Fig 53 RTU Open Overlay for Economizer Wiring ...
Page 36: ...36 Fig 54 VFD Overlay for W2770 Controller Wiring ...
Page 68: ...68 Fig B 50TCQD17 24 Control Wiring Diagram APPENDIX D WIRING DIAGRAMS ...
Page 69: ...69 Fig C 50TCQD17 24 Power Wiring Diagram 208 230 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 70: ...70 Fig D 50TCQD17 24 Power Wiring Diagram 460 3 60 575 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 71: ...71 Fig E RTU Open Overlay APPENDIX D WIRING DIAGRAMS ...
Page 72: ...72 Fig F PremierLink Overlay APPENDIX D WIRING DIAGRAMS ...