Protection Functions; Inverter Temperature Monitoring - Siemens SINAMICS G120D Operating Instructions Manual

Advanced commissioning

7.7 Protection functions

7.7 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.
7.7.1

Inverter temperature monitoring

The inverter temperature is essentially defined by the following effects:
● The ambient temperature
● The ohmic losses increasing with the output current
● Switching losses increasing with the pulse frequency
Monitoring types
The inverter monitors its temperature using the following monitoring types:
● I
● Measuring the chip temperature of the Power Module (alarm A05006, fault F30024)
● Measuring the heat sink temperature of the Power Module (alarm A05000, fault F30004)
Inverter response to thermal overload
Parameter Description
r0036
r0037
p0290
p0292
p0294
226
t monitoring (alarm A07805, fault F30005)
2
Power unit overload I
The I t monitoring calculates the inverter utilization based on a current reference value
2
defined in the factory.
Actual current > reference value: r0036 becomes higher.
•
Actual current < reference value: r0036 becomes lower or remains = 0.
•
Power unit temperatures [°C]
Power unit overload response
Factory setting and the ability to be changed depends on the hardware. The dependency
is described in the List Manual.
A thermal overload is present if the inverter temperature is greater than that specified in
p0292.
You define how the inverter responds if there is a risk of thermal overload using this
parameter. The details are described below.
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.
Power unit warning at I2t overload (factory setting: 95 %)
t [%]
2
Operating Instructions, 04/2015, FW V4.7.3, A5E34261542B AB
Converter with control units CU250D-2