Lenze 8400 motec Series, Software Manual, Page: 99 / 376

Firmware
≤
02.00 - DMS 2.1 EN - 03/2011
L
99
8400 motec | Software Manual
Motor control (MCTRL)
Parameterisable additional functions
below when the heatsink temperature has risen to 5 °C below the maximally permissible
temperature. After the heatsink has cooled down, the controller automatically switches to
the next frequency above until the set switching frequency is reached.
Switching frequency reduction due to high heatsink temperature can be deactivated via
C00144 . If the switching frequency reduction is deactivated, the "OH1: Heatsink
overtemperature" error message will be issued when the maximally permissible heatsink
temperature is reached. An "Fault" response is the result and the motor is coasting.
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. The changeover thresholds are
included in the "Rated data" chapter of the Hardware Manual.
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 "Fault".
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:

In the Lenze setting, the output frequency is limited to the maximum value of 300 Hz.
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 .
Display of the current switching frequency
The current switching frequency applied in the controller is displayed in C00725 .
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.
Parameter Info Lenze setting
C00144 Switching frequency reduction (temp.) 1: On
Maximum output frequency 1
8
---
Switching frequency
≤