NCF
EN
20
Problem
Reason
Cause
High power absorption
Excessive air flow
•
Excessive rotational speed.
•
Pressure resistance offered by the system lower than the
design value.
•
Fluid density higher than the design value.
High power absorption
•
Air flow already rotating in the opposite direction to the fan
rotation direction.
•
Motor power supply voltage lower than the value indicated
on the identification plate.
•
Faults in the motor windings.
Insufficient pressure
•
Rotational speed too low.
•
Fluid density lower than the design value.
Fluctuating fan operation
Unstable air flow
•
Low air flow.
•
Fluctuations in air flow due to fans working in parallel.
•
Vortices in the air induced by equipment near the air intake.
Vibrations
Fluctuating fan
operation
•
(see previous cause)
Vibrations
Unbalanced
rotating
components
•
Fan rotor wear.
•
Deposits on the fan rotor.
Vibrations
Mechanical
malfunction or
defects
•
Contact between moving and stationary components.
•
Intrinsic fault in the bearings.
•
Malfunction of the bearings due to unbalanced rotor.
Excessive noise
•
Contact between moving and stationary components.
•
Fluctuating fan operation.
•
Electromagnetic fault in motor.
•
Orifices or sharp angles in tubing.
5
Maintenance
CAUTION!
Risk of equipment damage.
Use only Nederman original spare parts and accessories.
Read Chapter 2 Safety before carrying out maintenance.
Installation, repair and maintenance work is to be carried out by qualified
personnel using only original Nederman spare parts. Contact your nearest
authorized distributor or Nederman for advice on technical service.
CAUTION!
Risk of equipment damage.
During any maintenance procedure, the fan must be disconnected and
insulated
from the electric power supply.
5.1
Checking and cleaning parts in contact with the fluid
The fan rotor should be cleaned regularly to prevent vibration caused by
dust accumulating on the blades during operation. If the fan is used to pump
even slightly dusty air, air containing abrasive powders or for the pneumatic
transport material, the cleanliness and wear of the fan rotor must be