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7.0 MAINTENANCE AND PERIODIC CONTROL
Unintended start-up during installing, controlling, maintenance or repair of
the fan has to be prevented!
The following must be controlled periodically (once a year):
1. Check if screws between impeller and hub got loose and tighten them if needed;
2. Tighten the screw between wheel hub and shaft if needed;
3. Remove dirt from the fan impeller if there is any;
4. Check the functionality of protective devices;
5. Check the functionality of control devices;
6. Current during operation;
7. Eventual vibrations;
8. Noise which might appear in el. motor bearings.
The function of the system and control devices has to be checked according to system
maintenance book, minimum every 3 months. Operation at least 15 minutes each time,
once a year 3 hours recommended, if possible.
Checking points 1 to 4 can be done only if the supply voltage is switched off
and possibility of unintended start-up is excluded.
Parameters of points 5 to 8 must not deviate from the starting values (at installation). In
case that parameters deviate, the electric motor or the impeller have to be replaced or
repaired. This must only be done by an authorised customer service, otherwise the
manufacturer's guarantee is invalid.
The electric motor has to be maintained according to the attached instructions of the
manufacturer of the electric motor.
8.0 SYSTEM MALFUNCTIONS DURING OPERATION
For all inspections, point 4.2. must be considered.
Possible malfunctions and solutions:
The fan does
not operate
Check connection to the mains in service switch. If ok. check connection
to controller.
Air volume is
too low
Check operating point and system design.
Under-,
overvoltage,
overheating,
overcurrent,
locked rotor
etc.
Please see chapter “Troubleshooting” in the instructions of controller.
Noise
Damage to the bearings, impeller blocked or touching the casing.
Get the electric motor or if necessary the complete fan repaired.
Vibrations
Check operating point and system construction. If the actual pressure
drop of the system is higher than supposed, the fan could operate in an
instable area of the fan curve. Inform customer service of the
