Siemens SINAMICS S120 Device Manual page 40

System overview
2.11 Derating data
Reducing the ambient temperature and the output current
Due to the reduced cooling efficiency, it is necessary, on the one hand, to reduce the
ambient temperature and, on the other, to lower heat loss in the Cabinet Module by reducing
the output current, whereby ambient temperatures lower than 104 °F (40 °C) may be offset
for compensation purposes. The following tables specify the permissible output currents as a
function of the installation altitude and ambient temperature for the various degrees of
protection. The specified values already include the permitted correction in respect of
installation altitude and ambient temperatures lower than 104 °F (40 °C) (inlet air
temperature at the air inlet of the Cabinet Module). The values apply under the precondition
that the cooling air flow through the devices – as specified in the technical data – is
guaranteed as a result of the cabinet installation.
Table 2- 5 Current derating factors as a function of the ambient temperature (inlet air temperature at the air inlet of the
cabinet unit) and installation altitude for cabinet units with degrees of protection IP20 / IP21/ IP23 (NEMA1 fil-
tered) / IP43
Installation altitude
above sea level
0 ... 6600 ft (0 to 2000 m)
... 8250 ft (... 2500 m)
... 9900 ft (... 3000 m)
... 11550 ft (... 3500 m)
... 13200 ft (... 4000 m)
... 14850 ft (... 4500 m)
... 16500 ft (... 5000 m)
Table 2- 6 Current derating as a function of the ambient temperature (inlet air temperature at the air inlet of the cabinet
unit) and installation altitude for cabinet units with IP54 enclosure (NEMA12 ventilated)
Installation altitude
above sea level
0 ... 6600 ft (0 to 2000 m)
... 8250 ft (... 2500 m)
... 9900 ft (... 3000 m)
... 11550 ft (... 3500 m)
... 13200 ft (... 4000 m)
... 14850 ft (... 4500 m)
... 16500 ft (... 5000 m)
40
at an ambient temperature (air intake temperature) of
68 °F 77 °F
(20 °C) (25 °C)
100 % 100 %
100 % 100 %
100 % 100 %
100 % 100 %
100 % 100 %
100 % 97.5 %
98.2 %
at an ambient temperature (air intake temperature) of
68 °F 77 °F
(20 °C) (25 °C)
100 % 100 %
100 % 100 %
100 % 100 %
100 % 100 %
100 % 96.3 %
97.5 % 92.1 %
93.0 %
Current derating factor
86 °F 95 °F
(30 °C) (35 °C)
100 % 100 %
100 % 100 %
100 % 98.7 %
100 %
96.3 %
Current derating factor
86 °F 95 °F
(30 °C) (35 °C)
100 % 100 %
100 % 96.3 %
98.7 % 92.5 %
94.7 %
90.7 %
104 °F 113 °F
(40 °C) (45 °C)
100 % 93.3 %
96.3 %
104 °F 113 °F
(40 °C) (45 °C)
93.3 % 86.7 %
89.8 %
Cabinet Modules NEMA
Manual, 04/2014, A5E03586450A
122 °F
(50 °C)
86.7 %
122 °F
(50 °C)
80.0 %