6
Upblast Centrifugal Roof Exhaust Fans
Model CUBE
Pre-Starting Belt Tension Checks
4. Always loosen tension enough to install belts without
stretching, see figure 9.
5. For units with two groove pulleys, adjust so the
tension is equal in both belts.
6. If adjustments are made, it is very important to check
the pulleys for proper alignment. Misaligned pulleys
lead to excessive belt wear vibration, noise and
power loss, see figure 10.
7. Belt tension can be adjusted by loosening four
fasteners on the drive frame, see figure 11. The
motor plate slides on the slotted adjusting arms and
drive frame angles in the same manner.
WARNING
The fan has been checked for mechanical noises at
the factory prior to shipment. If mechanical noise
should develop, suggested corrective actions are
offered in the Troubleshooting section.
IMPORTANT
Over tightening will cause excessive bearing wear and
noise. Too little tension will cause slippage at startup
and uneven wear.
Fig. 10
Do not force belt(s). Forcing the
belt(s) will break the cords and
cause belt failure
Belts
Fig. 9
Wheel Overlap and Gap Dimensions
Fig. 7
G
H
Model
G - Overlap in (mm)
H - Gap in (mm)
CUE 060-095
–
3/32
(2)
CUE 098-161
1/4
(6)
–
CUE 180-200
1/2
(13)
–
CUBE 098
–
3/32
(2)
CUBE 099-161
1/4
(6)
–
CUBE 180-300
1/2
(13)
–
CUBE 360-480
3/4
(19)
–
WARNING
Correct direction of wheel rotation is critical. Reversed
rotation will result in poor air performance, motor
overloading and possible burnout.
Pre-Starting Checks
1. Check all fasteners and set screws for tightness. The
wheel should rotate freely and be aligned as shown
in figure 7.
2. Wheel position is preset and the unit is test run at the
factory. Movement may occur during shipment and
realignment may be necessary.
CUE unit - Centering height alignment can be
accomplished by loosening the set screws in the
wheel and moving the wheel to the desired position.
CUBE unit - Centering can be accomplished by
loosening the bolts holding the drive frame to the
shock mounts and repositioning the drive frame.
CUBE unit - Wheel and inlet cone overlap can be
adjusted by loosening the set screws in the wheel
and moving the wheel to the desired position.
3. Check wheel rotation (viewing from the shaft side)
by momentarily energizing the unit. Rotation should
correspond to the rotation decal on the unit, see
figure 8. If wheel rotation is incorrect reverse two
of the wiring leads or check motor wiring for single
phase.
Wheel Rotation
All CUE Models
All CUBE Models
Fig. 8
Clockwise Airflow
Fasteners
*Identical fasteners on
opposing side must also be
loosened.
Fig. 11
(4) *Fasteners
®
