Siemens SINAMICS Series Operating Instructions Manual page 597

10.24 Sensor for the ambient and/or air intake temperature
For the SINAMICS DC MASTER, a sensor for the ambient and/or air intake temperature is
available as option (order code L15, see Chapter "Ordering information for options and
accessories (Page 30)"). The sensor is mounted in the cooling air intake of the device.
Please note that when ordering SINAMICS DCM, it is only possible to subsequently retrofit a
sensor in the manufacturer's factory.
● The temperature sensor is indicated as being available at r52049[1].
● The measured temperature is available at r52050[1] and at r50013[1] for example for the
following applications.
– For evaluation with "free function blocks" or "DCC charts" or
– For transfer to a higher-level automation system via fieldbus (PROFIBUS/PROFINET)
● The derating (see Chapter "Derating (Page 75)") is automatically adapted to the
measured air intake temperature.
Commissioning
If option L15 is being used, at p50077 the derating factor for the power reduction as result of
increased installation altitude (K2 according to the following table) must be set, and not the
derating factor according to the tables in Chapter "Derating (Page 75)".
Installation altitude
1000 m
2000 m
3000 m
4000 m
5000 m
Function
● Calculating the derating factor
Effective derating factor K = K1×K2
K1 = derating as a result of increased air intake temperature
K2 = derating as a result of increased installation altitude (see the previous table)
K1 is continually calculated, taking into account the measured air intake temperature
(limited to max. 1.0). The derating factor K is determined by multiplying with K2 and used
to generate the current limit r52130, see function diagram 8042 in the SINAMICS DCM
List Manual.
● Monitoring the air intake temperature
For self-ventilated (self-cooling, cooling type AN) devices, the following applies:
Alarm threshold = 52 °C
Fault threshold = 57 °C
For force-ventilated (with forced air cooling, type AF) devices, the following applies:
Alarm threshold= 47 °C
Fault threshold = 52 °C
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
10.24 Sensor for the ambient and/or air intake temperature
Derating factor K2
1.0
0.9
0.8
0.7
0.6
Descriptions of functions
595