Siemens MICROMASTER 420 - Manual (Page 142)

3 Functions Issue 07/04
MICROMASTER 420 Operating Instructions
142 6SE6400-5AA00-0BP0
No reduction (P0290 = 1)
This option should be selected if neither a reduction in the pulse frequency nor
a reduction in the output current is being considered. In this case, the drive
inverter does not change its operating point after the warning threshold has
been exceeded so that the drive can be further operated until the shutdown
values are reached. After the shutdown threshold has been reached, the drive
inverter shuts down (trips) with fault F0004. The time which expires up to
shutdown is however not defined and depends on the magnitude of the
overload. Only the warning threshold can be changed in order to obtain an
earlier warning and, if required, externally intervene in the drive process (e.g. by
reducing the load, lowering the ambient temperature).
NOTE
If the drive inverter fan fails, this would be indirectly detected by the
measurement of the heatsink temperature.
A wire breakage or short circuit of the temperature sensor(s) is also monitored.