Siemens Automation System S7-400 - Manual (Page 43)

Installing the S7-400
2-27
Automation System S7-400 Hardware and Installation
A5E00850741-01
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.
200 400 600 800 1000 1200 1400 W
Power dissipation
20
30
40
50
60
Ambient temperature in °C
1
2
3
Figure 2-2 Max. Cabinet Ambient Temperature as a Function of Power Dissipation of
Equipment in the Cabinet
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
Risk of damage to the modules.
Modules may be damaged as a result of excess ambient temperature.