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10 - OPERATION AND MAINTENANCE
10.3 - Fans
10.3.1 - Direct-drive fans
Periodic maintenance
■ Every 3 months
■ Every month for ATEX units
■ Follow the instructions given in section 10.1 General recommendations for cleaning
Warning!
Follow the safety instructions (see § 2 - SAFETY INSTRUCTIONS).
■ When working inside the unit, make sure that the motors are switched off and the fans are not running.
- Follow the instructions in § 9.4 Fans.
- Check the motor/fan/mountings assembly for corrosion.
- Check for noise and vibrations from the bearings.
- Check that the fan is clean. Fouled blades may lead to imbalance and breakdown of the fan.
- If the motor has a cooling grille, check that it is clean.
- Remove any impurities using a vacuum cleaner and/or a cleaning product.
- Check the protection components (grille, crankcase).
- Check the tightness of the electrical connections (see § 7.5 Connecting the fans).
- For plug fans, check the balance of the wheel and the deviation between the wheel and the frame (see page 24).
- Check the flexible connections.
- Check the anti-vibration mounts.
- Check the tightness of all mounting bolts.
10.3.2 - Direct drive fan
- Follow the instructions and settings in § 9.4 Fans
■ Bearings:
- The maintenance frequency for the bearings depends on the fans' operating conditions.
- Most fans have lifetime lubricated bearings.
- Some fans have bearings with their own lubricators. Observe the frequency and type of lubricant recommended by the fan
manufacturer.
■ Pulleys and belts:
- The maintenance frequency for the belts depends on the fans' operating conditions.
- Check the belt tension and wear.
- Check that the motor and fan pulleys are correctly aligned.
■ Replacing the belts:
- Reduce the centre distance (diagram opposite) so that the V-belt(s) can be positioned in
the groove without forcing. It is forbidden to force them using a lever, screwdriver or other
tool.
- On pulleys with several grooves, if one of the belts is faulty or worn, all of the belts must
be replaced simultaneously. V-belts of different makes and with different production dates
must not be used in a set of belts.
- If the fans are stopped for prolonged periods (more than three months), there is a risk of
bearing damage. To prevent this, we recommend reducing the belt tension or temporarily
removing the belts from the fan. When restarting the fans, the belt tension must be
readjusted to the specified value. Likewise, monthly rotation is recommended to prevent
the formation of a flat spot on the rollers.
10.3.3 - Disassembling the fan motor assemblies
■ When disassembling the fan motor assemblies, use suitable lifting equipment and comply
with the safety standards.
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