Maintenance/troubleshooting
14
DVV 16.08.2021
10.1
Malfunctions and troubleshooting (generally)
Possible reasons
Action
The ventilator
does not run
Connection to the mains fault.
Thermal protection triggers.
Motor fault.
Check connection to the mains and thermal protection. If
ok. check electric motor (winding resistance, resistance to
ground). If two speed motor (4-6, 6-8, 8-12, 4-8, 6-12) is
installed, check all speed. If necessary get the electric mo-
tor repaired.
Air volume is
too low
Wrong direction of rotation.
Too high pressure drop in system.
Obstacles in duct.
Check the direction of rotation. If wrong, swap the supply
connection of any 2 phases. Check if current is similar all
phases. If ok. check operating point and system design.
Thermal pro-
tection of the
fan switches
off
Short-circuit.
Damage to the bearings.
Impeller blocked or grinding.
Compare connection with wiring diagram. Compare the
data of electric motor with setting of thermal protection.
If ok. check power supply and electric motor. Get the
electric motor or if necessary the complete fan repaired.
Overcurrent
Check the direction of rotation. If wrong, swap any 2
phases. Check if current is similar all phases.
Noise
Damage to the bearings.
Impeller blocked or grinding.
Get the electric motor or if necessary the complete fan re-
paired.
Loose fit on the base plate or mo-
tor support.
Tighten the bolts, look for the cause of vibrations.
Vibrations
The actual pressure drop of the
system is higher than supposed,
the fan could operate in an unsta-
ble area of the fan curve.
Check operating point and system design. Consult cus-
tomer service of the manufacturer.
Damage or dust layer on impeller.
Clean the impeller, if necessary balance it or replace it.
If the reason for malfunction cannot be clearly determined, consult the customer service of manufacturer.
10.2
Cleaning
Regular cleaning prevents unbalance.
Keep casing and impeller clean and clean them if necessary with a brush (do not use a steel brush or high-pres-
sure cleaner). Do not use any detergents for interior cleaning. Regular cleaning is particularly important, if
there are trees in the neighbourhood. The gap between casing and base plate must be kept free for water drain
and may not be covered by needles or leaves.
10.3
Maintenance, service
Basically the fan may be repaired at the manufacturer only! Exceptions are non-relevant components. For further in-
structions consult the manufacturer.
The fan is by built-in for-life lubricated ball bearings as far as possible low-maintenance product. After their life time
(app. 30.000
–
40.000 h), a replacement of the bearings is necessary. Observe attached instructions of motor manu-
facturer.
Pay attention to a non-typical noise from bearings.
For damages (e.g. damage to winding) please contact our Service Department. You will find the address on the
back of these operating instructions.
Maintenance and check points
of fans similarly to VDMA 24186-1 (type, scope and maintenance intervals to be speci-
fied in dependence of use and operating conditions).
