Firmware 03.00 - DMS EN 5.0 - 07/2009
L
95
8400 BaseLine D | Software Manual
Motor control (MCTRL)
Selection of the switching frequency
Lowering of the switching frequency depending on the output current
"Variable" switching frequencies can be selected for the controller in
controller automatically lowers the switching frequency depending on the controller
output current. The changeover threshold is included in the rated data of the Hardware
Manual. (The Hardware Manual can be found on the CD supplied with the device.)
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", see code
Tip!
The Lenze setting "8 kHz
var
value "2") is the optimum value for standard
applications.
Limiting the maximum output frequency
The maximum output frequency of the controller is not limited depending on the
switching frequency.
For this reason, adapt the maximum output frequency according to our recommendation:
Carry out further measures:
If required, deactivate the switching frequency changeover by the heatsink
temperature
If required, ensure that the changeover threshold of the controller output current to
the next smaller switching frequency will not be exceeded. If required, select a fixed
switching frequency using code
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.
Note!
For operation with a switching frequency of 16 kHz,
• the controller output current must not exceed the current limit values given
in the technical data. Reduce the output current using the codes
• the Ixt evaluation
is considered with the required derating to 0.67 I
rated
(I
rated
- rated device current) at switching frequencies of 2, 4 and 8 kHz.
At a switching frequency of 4 kHz, for instance,
125 Hz for the maximum output frequency should
not be exceeded.
Maximum output frequency
1
32
------
Switching frequency
≤
