Protection Functions; Inverter Temperature Monitoring - Siemens SINAMICS G120 Operating Instructions Manual

Functions

8.7 Protection functions

8.7 Protection functions
The frequency inverter offers protective functions against overtemperature and overcurrent
for both the frequency inverter as well as the motor. Further, the frequency inverter protects
itself against an excessively high DC link voltage when the motor is regenerating.
8.7.1

Inverter temperature monitoring

The inverter temperature is essentially determined by the resistive losses of the output
current and the switching losses which occur when pulsing the Power Module. The inverter
temperature falls when either the output current or the pulse frequency of the Power Module
is reduced.
I2t monitoring (A07805 - F30005)
The Power Module's I2t monitoring controls the inverter utilization by means of a current
reference value. The utilization is specified in r0036 [%].
Monitoring the chip temperature of the power unit (A05006 - F30024)
The temperature difference between the power chip (IGBT) and heat sink is monitored using
A05006 and F30024. The measured values are specified in r0037[1] [°C].
Heat sink monitoring (A05000 - F30004)
The power unit heat sink temperature is monitored using A05000 and F30004. The values
are specified in r0037[0] [°C].
Inverter response
Parameter
P0290
P0292
190
Description
Power unit overload response
(factory setting for SINAMICS G120 inverters with Power Module PM260: 0;
factory setting for all of the inverters: 2)
Setting the reaction to a thermal overload of the power unit:
0: Reduce output current (in vector control mode) or speed (in V/f mode)
1: No reduction, shutdown when overload threshold is reached (F30024)
2: Reduce pulse frequency and output current (in vector control mode) or pulse
frequency and speed (in V/f mode)
3: Reduce pulse frequency
Power unit temperature warning threshold (factory setting: Heat sink [0] 5°C, power
semiconductor [1] 15°C)
The value is set as a difference to the shutdown temperature.
Operating Instructions, 01/2011, FW 4.4, A5E02999804A AB
SINAMICS G120C Inverter