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IOM_ACVBA-ACVA_351a2402_207958_180109_EN
ACVBA-ACVA
PACKAGED VERTICAL COMPACT UNITS
AIR-AIR
OPTIONAL
EC MOTOR FANS
Diagnosis / Faults
Trouble shooting
Type of error
Possible cause
Solution
Fan does not run
(anymore)
Failure line voltage. Failure of one
phase. Under
– or overvoltage.
Check line voltage.
Earth fault.
Check motor connection and line voltage.
Short circuit winding.
Replace fan.
The thermal protection of the motor has
triggered (motor is overheated)
Check for free air passages; remove foreign bodies if necessary "Impeller
blocked or dirty". Check temperature of supply air. Check voltage.
Impeller blocked or dirty
Switch off power to the motor and secure against switching back
on.
Check safe isolation from supply.
Remove safety grille.
Remove foreign bodies or soiling.
Remount the safety grille.
Fan will not start
Temperature too low for bearing
grease.
Insert bearing with cold greasing.
Air stream wrong direction (Motor turns
in wrong direction at high speed)
Check air stream.
Behaviour in rotation by air current in reverse direction.
Fan
turns
too
slowly
Impeller / blade scrapes / brushes.
When indicated clear foreign bodies / dirt from the fan.
Active
temperature
management
effective (Motor or electronics over-
heated).
Check for free air passages; remove foreign bodies if necessary. "Impeller
blocked or dirty". Check temperature of supply air. Check installation
space (air speed overheat sink).
Air flow too low
Fan turns too slowly
“Fan turns too slowly”.
Airways blocked
Check for free air passages (supply/exhaust air vents, filters) “Impeller
blocked or dirty”
Pressure loss different to planned.
Check fan selection.
Vibrations
Imbalance.
Check blades for damage, soiling or ice. “Impeller blocked or dirty”
No or wrong vibration dampers (only in
radial)
Install correct vibration dampers
Unusual noises
Bearing damaged / worn.
Change bearings.
Impeller / blade scrapes / brushes.
When indicated clear foreign bodies / dirt from the fan. “Impeller blocked
or dirty”
Operation beyond stall point (for axial
fans)
Check for free air passages (supply / exhaust air vents, filters)
Wrong overlap on nozzle ( for
centrifugal fans)
Observe the installation instructions.
