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Siemens D 21.4 · 2017
SINAMICS S120 drive system
Chassis format
Liquid-cooled units in chassis format
7
■
Characteristic curves
(continued)
Derating
Liquid-cooled SINAMICS S120 chassis format units are rated for
an ambient temperature of 45 °C (113 °F) and installation alti-
tudes up to 2000 m (6562 ft) above sea level. At ambient tem-
peratures > 45 °C (113 °F), the output current must be reduced.
Ambient temperatures above 50 °C (122 °F) are not permissible.
At installation altitudes > 2000 m (6562 ft) above sea level, it
must be taken into account that the air pressure, and therefore
air density, decreases as the height increases. As a conse-
quence, the cooling efficiency and the insulation capacity of the
air also decrease.
Current derating as a function of the temperature of the cooling liquid
1)
Current derating as a function of ambient temperature
1)
1)
The factors of the two curves must not be multiplied. The highest value
in each case must be assumed for the purposes of calculation, so that
the derating factor in the worst-case scenario is 0.9.
Permissible ambient temperature as a function of installation altitude
Voltage derating as a function of installation altitude
Coolant temperature
G_D213_EN_00037b
without antifreeze
with antifreeze
Output current
(23) (32)
(50)
(68)
(86)
(104)(113)(122)
(140)
(°F)
10
20
°C
0
-5
30
40
50
10
0
20
30
40
%
50
45
60
100
60
70
80
90
Ambient temperature
G_D213_EN_00038
Rated current
(50)
(68)
(32)
(23)
(86)
(104)
(122)
(140)
10
20
°C
0
-5
30
40
50
10
0
20
30
40
%
50
60
100
60
70
80
90
110
Installation altitude above sea level
G_D213_EN_00072
Permissible ambient temperature (air)
°C (°F)
Ambient temperature
T
max
at I = 100 %
Ambient temperature
T
max
at I = 90 %
(3281)
(6562)
(9843)
(13124)
(122)
(50)
(32)
(68)
(86)
(104)
m (ft)
1000
2000
0
3000
4000
50
10
0
20
30
40
Installation altitude above sea level
G_D213_EN_00080
Permissible input voltage in %
of rated voltage
(3281)
(6562)
(ft)
(9843)
(13124)
1000
2000
m
0
3000
4000
100
90
80
70
1)
The factors of the two curves must not be multiplied. The highest value in
each case must be assumed for the purposes of calculation, so that the
derating factor in the worst-case scenario is 0.9.
© Siemens AG 2017