Lenze 8400 - Manual (Page 244)

5 Motor control (MCTRL)
5.10 Parameterisable additional functions
244
Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
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Lowering of the switching frequency depending on the output current
"Variable" switching frequencies can be selected for the controller in
C00018 , where the controller
automatically lowers the switching frequency depending on the controller output current. The
modulation mode will not be changed.
When a "fixed" switching frequency is selected, no switching frequency changeover takes place. In
case of fixed frequencies, the controller output current is limited to the permissible value of the
corresponding switching frequency. In case of larger load impulses, the overcurrent interruption
may be activated, to which the controller responds with "Error".
Limiting the maximum output frequency
The maximum output frequency ( C00910 ) of the controller is not limited depending on the
switching frequency. Therefore, adapt the maximum output frequency according to our
recommendation:
• At a switching frequency of 4 kHz, for instance, 500 Hz for the maximum output frequency
should not be exceeded.
Carry out further measures:
• If required, deactivate the switching frequency changeover by the heatsink temperature via
C00144 .
• If required, ensure that the changeover threshold of the controller output current to the next
switching frequency below will not be exceeded. If required, select a constant switching
frequency in C00018 .
Operation at an ambient temperature of 45°C
The controller is designed so that operation at an ambient temperature of 45° C without derating is
permissible at a switching frequency of 4 kHz.

The switching thresholds are given in the rated data in the 8400 protec hardware
manual.
• The hardware manual has been stored in electronic form on the data carrier supplied
with the 8400 drive controller.

Note!
If the servo control mode (SC) is selected, the drive assumes the 'maximum current
limitation' state if the maximum output frequency ( C00910 ) has been reached.
 Defining current and speed limits ( 145)
Maximum output frequency 1
8
--- Switching frequency ≤