Roof Supply Fan
6
®
IMPORTANT
Supply fans should be operated only when attached
to the completed system. Without proper static
pressure loading, the motor may be overloaded and
burnout may occur.
Units with motor and drives shipped separate, refer to
Motor Mounting Instructions included in hardware bag.
Check all fasteners and set screws for tightness. Rotate
the fan wheel by hand to assure it turns freely and is
centered between the inlets. Check pulleys and belts for
proper alignment to avoid premature belt wear, noise,
vibration and power loss. Motor and fan pulleys must be
parallel and in alignment, see Figure 2.
Adjustable motor pulley is set at the factory for the fan
RPM specified. Fan speed can be increased by closing
or decreased by opening the adjustable motor pulley.
Two groove variable pitch pulleys must be adjusted an
equal number of turns open. Any increase in fan speed
results in an increase in horsepower required for the
motor. Motor amperage should always be checked
and compared to nameplate rating when changing fan
speed.
DANGER
Disconnect and secure to the “off” position all
electrical power to the fan prior to inspection or
servicing. Failure to comply with this safety precaution
could result in serious injury or death.
DANGER
Pour écarter les risques de blessure grave ou de mort,
débrancher et verrouiller l’alimentation électrique en
position « Arrêt » avant tout contrôle ou entretien.
CORRECT
WRONG
WRONG
WRONG
Figure 2
Pre-Starting Checks
Direction of fan wheel rotation is critical. A fan wheel
rotating in the wrong direction will result in reduced
airflow, motor overloading and
possible burnout. Check wheel
rotation by momentarily turning
the fan on.
Rotation should be in the same
direction as airflow at the outlet.
See housing and wheel example
in Figure 3.
Airflow
Rotation
Figure 3
