Siemens SINAMICS G120 - Protection Functions; Inverter Temperature Monitoring

Setting functions
8.6 Protection functions
Inverter with CU230P-2 Control Units
Operating Instructions, 11/2013, FW V4.6.6, A5E02430659B AG
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8.6
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.
8.6.1
Inverter temperature monitoring
The inverter temperature is essentially defined by the following effects:
● The ohmic losses in the inverter
● The switching losses that occur when the motor is pulsed
Monitoring types
The inverter monitors its temperature using the following monitoring types:
● I
2
t monitoring (alarm A07805, fault F30005)
The I
2
t monitoring calculates the inverter utilization on the basis of a current reference
value predefined by the factory.
– Actual current > reference value: The actual value of the utilization increases.
– Actual current < reference value: The actual value of the utilization decreases or
remains = 0.
● Measuring the chip temperature of the power unit (alarm A05006, fault F30024)
● Measuring the heat sink temperature of the Power Module (alarm A05000, fault F30004)