Greenheck G/GB (471558) - Manual (Page 7)

Downblast Centrifugal Roof Exhaust 7
®
9. For GB units: 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.
Four (4) fasteners in
total.
Identical fasteners on
opposing side must
also be loosened.
Figure 11
Model GB Pre-Starting Belt Tension Checks
6. Always loosen tension enough to install belts
without stretching, see Figure 9.
Do not force belt(s). Forcing the belts will break the
cords and cause belt failure.
7. For units with two groove pulleys, adjust so the
tension is equal in both belts.
8. 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.
Pre-Starting Checks
1. Check all fasteners and setscrews 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.
3. Only G model - Centering height alignment can
be accomplished by loosening the set screws in
the wheel and moving the wheel to the desired
position.
4. Only GB model - Centering can be accomplished
by loosening the bolts holding the drive frame
to the shock mounts and repositioning the drive
frame.
Wheel and inlet cone overlap can be adjusted by
loosening the set screws in the wheel and moving
the wheel to the desired position.
Fan RPM should be checked and verified with a
tachometer.
5. Check wheel rotation (viewing from the shaft side)
by momentarily energizing
the unit. Rotation should be
clockwise as shown in Figure
8 and correspond to rotation
decal on the unit.
If wheel rotation is incorrect,
reverse two of the wiring leads
or check motor wiring for
single phase.
Model Size
Overlap
in. (mm)
Gap
in. (mm)
G 060-095 – 3/32 (2)
G 097-163 1/4 (6) –
GB 071-161 1/4 (6) –
G 183-243 3/8 (10) –
GB 180-240 3/8 (10) –
GB 260-540 1/2 (13) –
Overlap Gap
Figure 7
Clockwise Rotation
Figure 8
Figure 9
Figure 10
WARNING
Correct direction of wheel rotation is critical.
Reversed rotation will result in poor air performance,
motor overloading and possible motor burnout.
AVERTISSEMENT
La turbine doit impérativement tourner dans le bon
sens. Une rotation en sens inverse entraînerait
de mauvaises performances de soufflage, une
surcharge du moteur voire un grillage du moteur.
IMPORTANT
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.
CORRECT WRONG WRONG WRONG