Siemens SIMATIC S7-400 Hardware And Installation Manual page 45

Removable Power Dissipation from Cabinets (Example)
The removable power dissipation from a cabinet is governed by the type of
cabinet, its ambient temperature, and the arrangement of equipment in the cabinet.
Figure 2-2 shows a diagram with guide values for the permissible ambient
temperature of a cabinet measuring 600 x 600 x 2000 mm as a function of power
dissipation. These values only apply if you observe the specified installation
dimensions and clearances for racks. Further information can be found in Siemens
catalogs NV21 and ET1.
Ambient temperature
o
in C
60
50
40
30
20
Figure 2-2
Legend for Figure 2-2:
1. Closed cabinet with heat exchanger; heat exchanger size 11/6 (920 x 460 x
111 mm)
2. Cabinet with through-ventilation by natural convection
3. Closed cabinet with natural convection and forced circulation by equipment fans
Warning
!
Modules can be damaged.
Modules can be damaged by subjecting them to excessively high ambient
temperature.
In the case of modules with hard drives, in particular, ensure that they are not
subjected to an excessively high ambient temperature.
S7-400 and M7-400 Programmable Controllers, Installation Manual
C79000-G7076-C424-01
www.gkbpx.com
2
3
200 400 600 800
Max. Cabinet Ambient Temperature as a Function of Power Dissipation of
Equipment in the Cabinet
Installing the S7-400
1
1000 1200 1400 W
Power dissipation
2-25