Siemens SINAMICS G130 Engineering Manual page 213

Ambient
temperature
10 ℃
T
20 %
a
20 ℃ < 0 °C < 0 ℃
25 ℃ 0.6 ℃
30 ℃ 4.7 ℃
35 ℃ 8.7 ℃
40 ℃
45 ℃ 12.8℃
50 ℃ 16.8℃
20.8℃
Dew point T as a function of ambient temperature T
dp
According to the table above, the difference between the dew point T
virtually constant for a given relative air humidity Φ when the ambient temperature T
temperature rises, the difference between the dew point T
particularly under conditions of relatively low air humidity.
As a result of this correlation, it is possible to use the 3rd line from the above table (applicable to an ambient
temperature of 25°C) in order to calculate the temperature difference ΔT
in order to keep the coolant temperature setpoint T
ambient air.
Relative air humidity Φ 20 %
Dew point at ambient
0.6℃
temperature of 25℃
Difference between dew
point and ambient
-24.4℃
temperature T – T
dp a
Addition of 4°C as
safety margin to the
-20.4℃
dew point:
ΔT = (T – T ) + 4°C
L dp a
Calculation of the temperature difference ΔT
condensation
The diagram below shows the temperature difference ΔT
air according to the last line in the table above.
Temperature difference ΔT
L
Fundamental Principles and System Description
< 0 ℃ < 0 ℃ 0.2 ℃
30 % 40 % 50 %
2.0 ℃ 6.0 ℃ 9.3 ℃
6.3 ℃
10.5℃ 13.8℃
10.5°C 14.9℃ 18.4℃
14.8℃ 19.3℃ 22.9℃
19.1℃ 23.7℃ 27.5℃
23.3℃ 28.2℃ 32.0℃
27.5℃ 32.6℃ 36.6℃
and relative air humidity Φ
a
30 % 40 % 50 %
10.5°C 13.8°C
6.3℃
-18.7℃ -14.5℃ -11.2℃
-14.7℃ -10.5℃ -7.2℃
that must be added to the ambient temperature T
L
as a function of relative air humidity Φ
Relative air humidity Φ
2.7 ℃ 4.8 ℃ 6.7 ℃
60 % 70 % 80 %
12.0℃ 14.3℃ 16.4℃
16.7℃ 19.1℃ 21.2℃
21.3℃ 23.8℃ 26.1℃
26.0℃ 28.6℃ 30.9℃
30.6℃ 33.4℃ 35.8℃
35.3℃ 38.1℃ 40.6℃
40.0℃ 42.9℃ 45.5℃
and the ambient temperature T
dp
and the ambient temperature T
dp
to be added to the ambient temperature T
L
always at least 3°C to 5°C higher than the dew point of the
set
60 % 70 % 80 %
16.7°C 21.2°C
19.1℃
-8.3℃ -5.9℃ -3.8℃
-4.3℃ -1.9℃ +0.2℃
as a function of the relative air humidity Φ of the ambient
L
SINAMICS Engineering Manual – November 2015
Engineering Information
7.6 ℃ 8.4 ℃ 9.2 ℃
85 % 90 % 95 %
17.4℃ 18.3℃ 19.1℃
22.2℃ 23.2℃ 24.1℃
27.1℃ 28.1℃ 29.0℃
32.0℃ 33.0℃ 34.0℃
36.9℃ 37.9℃ 38.9℃
41.8℃ 42.9℃ 43.9℃
46.6℃ 47.8℃ 48.9℃
a
is ≤ 25°C. As the ambient
a
increases slightly,
a
85 % 90 % 95 %
22.2°C 23.2°C 24.1°C
-2.8℃ -1.8℃ -0.9℃
+1.2℃ +2.2℃ +3.1℃
in order to prevent
a
213/528
Ó Siemens AG
100 %
10.0℃
20.0℃
24.9℃
29.9℃
34.9℃
39.9℃
44.9℃
49.9℃
remains
a
100 %
24.9°C
-0.1℃
+3.9℃