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Siemens S5-135U/155U User Manual

Page 64

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3-38

System Manual

C79000-G8576-C199-06

!

Caution

Modules with a hard disk drive can only be used at an ambient temperature
of up to 50

°

C.

3.7.4

Examples for Determining the Type of Cabinet

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

200 W

2

Expansion units, 250 W power dissipation each

500 W

1

Load PS, 24 V/40 A, 6EV1 362-5BK00 (full load)

200 W

Total power disspation

900 W

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

Max. Permissible Ambient
Temperature

Closed, with natural convection and forced
circulation (Curve 3)

(Operation not possible)

Open with through-ventilation (Curve 2)

Approx. 33

°

C

Closed, with heat exchanger (Curve 1)

Approx. 42

°

C

Installation Guidelines