Siemens CU240B-2 Operating Instructions

6.27 Inverter protection using 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
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)
Inverter response to thermal overload
Parameter Description
r0036 Power unit overload I
2
t [%]
The I
2
t monitoring calculates the inverter utilization based on a current reference value
defined in the factory.
● Actual current > reference value: r0036 becomes higher.
● Actual current < reference value: r0036 becomes lower or remains = 0.
r0037 Power unit temperatures [°C]
p0290 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 pa‐
rameter. The details are described below.
p0292 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.
p0294 Power unit warning at I2t overload (factory setting: 95 %)
Overload response for p0290 = 0
The inverter responds depending on the control mode that has been set:
● In vector control, the inverter reduces the output current.
● In U/f control, the inverter reduces the speed.
Once the overload condition has been removed, the inverter re-enables the output current or
speed.
Advanced commissioning
6.27 Inverter protection using temperature monitoring
Converter with the CU230P-2 Control Units
322 Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE

Siemens CU240B-2 Specifications

General

Brand	Siemens
Model	CU240B-2
Category	Inverter
Language	English