Efficient Networks S120 manual Block protection

Monitoring and protective functions 8.3 Block protection

Reducing the output frequency has the effect of significantly reducing the converter output current which, in turn, reduces losses in the power unit.

● No reduction (p0290 = 1)

You should choose this option if it is neither possible to reduce the pulse frequency nor reduce the output current. The converter does not change its operating point once an alarm threshold has been overshot, which means that the drive can be operated until it reaches its shutdown values. Once it reaches its shutdown threshold, the converter switches itself off and the "Overtemperature, overload" fault is output. The time until shutdown, however, is not defined and depends on the degree of overload.

To ensure that an alarm can be output earlier or that the user can intervene, if necessary, in the drive process (e.g. reduce load/ambient temperature), only the alarm threshold can be changed.

Function diagrams (see SINAMICS S List Manual)

● 8014 Thermal monitoring, power unit

Overview of key parameters (see SINAMICS S List Manual)

●r0036 Power unit overload

●r0037 Power unit temperatures

●p0290 Power unit overload response

●p0294 Alarm threshold I2t overload power unit

8.3Block protection

Description

The error message "Motor blocked" is only triggered if the speed of the drive is below the variable speed threshold set in p2175. With vector control, it must also be ensured that the speed controller is at the limit. With V/f control, the current limit must already have been reached.

Once the ON delay (p2177) has elapsed, the message "Motor blocked" and fault F7900 are generated.

Drive Functions	293
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4