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

Functions

9.7 Protection functions

9.7 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.
9.7.1

Inverter temperature monitoring

The inverter protects itself against overtemperature with different monitoring functions:
1. I2t monitoring (alarm A07805, fault F30005)
2. Monitoring the chip temperature of the power unit (alarm A05006 - fault F30024)
3. Heat sink monitoring (alarm A05000, fault F30004)
Inverter response
The inverter temperature is essentially determined by the resistive losses of the output
current and the switching losses which occur when pulsing the motor. Parameter p0290
defines how the inverter responds to an excessively high temperature.
Parameter
P0290
P0292
194
The I t monitoring measures the actual utilization on the basis of a current reference
2
value. Parameter r0036 [%] displays the actual utilization as a %. As long as the actual
current does not exceed the reference value, then the utilization in r0036 = 0.
The inverter monitors the difference in temperature between the power chip (IGBT) and
the heat sink. The measured values are in r0037[1] [°C].
The inverter monitors the heat sink temperature of the Power Module. The values are in
r0037[0] [°C].
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.
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB