Instructions for Direct Drive Tube Axial, Venturi & Upblast/Hooded Roof Fans
If motor is three-phase type, reverse rotation (if required) by interchanging any two of the three power leads. If
two-phase, interchange stator leads of either phase, being careful not to change leads from one phase to the
other. If motor is single-phase, refer to the instructions on the motor nameplate.
After installation is completed, but before fan is put in regular service, make an initial start as follows:
Visually check the blade tolerances to see that they are equal around the fan. Hand turn the impeller to
determine that the motor has not shifted in shipment and/or erection. Be sure no blades are touching the
housing when spun.
Check that motor, starting, and control device connections agree with wiring diagrams.
Check that voltage, phase and frequency of line circuit (power supply) agree with fan nameplate.
Check that all bolts on your fan supports are tight and no objects are left in the fan housing.
Check motor service record and tag accompanying motor to be certain bearings have been properly lubricated.
When shipped from the factory, relubricable ball bearings have been lubricated to give six (6) months
satisfactory service. Sealed ball bearings are lubricated for life and require no maintenance.
Bump start the fan to determine if the fan is turning the correct way in accordance with the rotation arrow on the
outside of the fan casing.
Repeated trial starts can overheat the motor (particularly for across-the-line starting) or the resistance of external starting
equipment. If repeated trial starts are made, allow sufficient time between trials to permit heat to be dissipated from
windings or external resistance and prevent overheating. Starting currents are several times running currents, and
heating varies as the square of the current.