Examples For Determining The Type Of Cabinet - Siemens S5-155U System Manual

Selection and Installation of Cabinets with SIMATIC S5
3.7.4
Examples for Determining
the Type of Cabinet
3 - 40
Caution
Modules with a hard disk drive can only be used at an ambient
o
temperature of up to 50 C.
The following example shows the maximum permissible ambient
temperature with various cabinet types and the same power dissipation.
Example
The following equipment configuration is given:
1 Central controller
2 Expansion units, 250 W power dissipation each
1 Load PS, 24 V/40 A, 6EV1 362-5BK00 (full load)
Total power dissipation
From Figure 3-16, with a total power dissipation of 900 W, the
maximum ambient temperatures given by the table are as follows:
Cabinet Design
Closed, with natural convection and
forced circulation (Curve 3)
Open with through-ventilation (Curve 2)
Closed, with heat exchanger (Curve 1)
200 W
500 W
200 W
900 W
Max. Permissible
Ambient
Temperature
(Operation not
possible)
o
Approx. 33 C
o
Approx. 42 C
System Manual
C79000-B8576-C199-03