Siemens 420 manual No reduction P0290 =

3 Functions Issue 07/04

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.

MICROMASTER 420	Operating Instructions
142	6SE6400-5AA00-0BP0