7.1
Operation of the fans on a frequency inverter
7.1.1
Frequency inversion with sine fi lter with all-pole effect
NOTE
Do not confuse the all-pole sine fi lters with motor fi lters (often also called damping or du/dt fi lters).
In external rotor motors, an all-pole sine fi lter has to be fi tted between the motor and the frequency inverter for operation on fre-
quency inverters. We recommend the use of sine fi lters with an all-pole effect for operation of all Systemair fans on frequency invert-
ers.
Sine fi lters with an all-pole effect provide sine-shaped output voltages phase to phase and phase to protective conductor coming close
to the requirements of DIN EN 61000, part 2-2.
If your regulate by a frequency inverter, install an all-pole sine fi lter between the motor and the frequency inverter (all-pole:
phase to phase, phase to earth).
7.1.2
Frequency inversion without a sine fi lter with all-pole effect
In frequency inverters without a sine fi lter with an all-pole effect, particular measures are necessary in the installation and connection
of the motors. These measures can be seen from the operating instructions from the manufacturer of the frequency inverter.
In speed control via frequency inverter, please remember that voltage peaks on the motor terminals must be less than 1000 V
and voltage increase velocities less than 500 V/μs (IEC 34-17).
If you have a long motor feed line, use an output fi lter between the frequency inverter and the motor.
7.2
Protect the motor
Avoid two-phase running:
At 3-phase motors, use an all-pole C- or K-safety cut-out (current consumption, see name plate). (Current con-sumption see name
plate).
7.3
Connection of thermal protection
If motor provided with built-in thermal protection, it must be connected to a triggering device and/or a motor-protection device.
8
Commissioning
8.1
Preconditions
•
•
Mounting and electrical connection have been correctly performed.
•
•
Installation residuals and foreign objects have been removed from the fan and ducts.
•
•
Inlet and outlet are free.
•
•
The safety devices have been fi tted (protection against contact).
•
•
Grounding connected.
•
•
The thermo-contacts (temperature monitors) have been properly connected to the motor protective device.
•
-
The motor protective device is functional.
•
-
The thermal protection is functional.
•
•
The cable glands are tight.
•
•
Provided mains connection complies with the data on the name plate. Voltage tolerances are admissible pursuant to IEC 38
at a maximum of +6% or -10%. The nominal current may only exceed the nominal voltage by a maximum of 5 %.
•
•
Nominal current (from the name plate) does not exceed the mains data.
•
NOTE
If the speed is regulated by voltage reduction, the engine current can exceed the nominal current at low voltages. In
such a case, the motor coil is protected by thermo-contacts.
»
However, make absolutely show whether a minimum static back pressure has been stated for the fan.
46
Commissioning
Roof fans - V 1.0
