12
10.2. Fans with variable speed
Warning
Resonant frequencies can result in increased vibrations in certain speed ranges. These vibrations can destroy
components.
•
Only operate the fan outside these speed ranges.
•
Let these speed ranges run through so fast that no oscillation can exceed the values for theResonance frequency.
•
The operating instructions of the frequency inverter must be observed.
Caution
Damage resulting from incorrect commissioning of the frequency inverter.
•
The fan and frequency converter must be installed as close as possible to each other.
•
Use shielded cables.
•
All components (fan, frequency converter and motor) must be grounded.
•
All-pole sine filters must be used. (Exceptions are fans with IEC standard motors. This is not mandatory for these
motors, but is recommended by Walpol)
•
Avoid fan operation with frequency converter below 10 Hz.
•
The heating of the motor when using a frequency converter must be checked by the customer in the application.
•
Never exceed the maximum impeller speed specified on the fan nameplate.
11. Commissioning
The warranty is only valid if commissioning has been carried out correctly and written proof of this has been
provided.
Safety instructions
Commissioning may only be carried out by appropriately qualified persons, for details, see table Qualification
Requirements
• Assembly and electrical connection are profession-
ally completed.
• Inlet and outlet are free.
• Residual material from the installation and foreign
bodies were removed from the fan and ducts.
• The cable glands were tightened firmly.
• Check the fan for visible damage before switching it
on and ensure that the protective devices are
functioning properly.
• The data on the nameplate correspond to the
connection data.
• Use all locking screws.
• The safety devices have been installed.
• Install a permanent disconnecting device in the
electrical installation (all-pole contact opening min.
3 mm).
Tests
