8.23 Converter protection using temperature monitoring
Overview
The converter temperature is essentially dened by the following eects:
• The ambient temperature
• The ohmic losses increasing with the output current
• Switching losses increasing with the pulse frequency
Monitoring types
The converter monitors its temperature using the following monitoring types:
• I
2
t monitoring (alarm A07805, fault F30005)
• 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)
Function description
Overload response for p0290=0
The converter responds depending on the control mode that has been set:
• In vector control, the converter reduces the output current.
• In U/f control, the converter reduces the speed.
Once the overload condition has been removed, the converter re-enables the output current
or speed.
If the measure cannot prevent a converter thermal overload, then the converter switches o
the motor with fault F30024.
Overload response for p0290=1
The converter immediately switches o the motor with fault F30024.
Overload response for p0290=2
We recommend this setting for drives with square-law torque characteristic, e.g. fans.
Advanced commissioning
8.23Converter protection using temperature monitoring
SINAMICS G120C Converters
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK 337