Installing the S7-400
2-28 AutomationSystem S7-400 Hardwareand Installation
A5E00850741-01
Example of selecting the cabinet type
The example below clarifies the maximum permissible ambient temperature at a
particular power loss for various cabinet types.
Equipment suitable for installation in a cabinet:
1 central rack 150 W
2 expansionracks, 150Watts each 300 W
1 loadcurrent powersupply under full load 200 W
Accumulated power loss 650 W
Permissible ambient temperatures at an accumulated power loss as shown in
Figure 2-2:
Typeof Cabinet Max. Permissible Ambient
Temperature
Closed, with natural convection and forced circulation
(Curve 3)
(no operation possible)
Open, with through-ventilation (Curve 2) approx. 38°C
Closed, with heat exchanger (Curve 1) approx. 45°C
Cabinet dimensions
Vital dimensional design factorsfor anS7-400 cabinet
•Space requirement of the racks
•Minimum clearance between racks and cabinet walls
•Minimum clearance between racks
•Space requirement of cable ducts or fan subassemblies
•Locations of rails