Siemens S5-135U/155U appendix Removal of Power Dissipation from Cabinets

Installation Guidelines

3.7.3Removal of Power Dissipation from Cabinets

The power dissipation that can be removed from a cabinet is governed by the cabinet design, its ambient temperature and the arrangement of equipment in the cabinet.

Shown in the following figure is a diagram with guide values for the permissible ambient temperature of a cabinet measuring 600 x 600 x 2200 mm, as a function of power dissipation. These values only apply to the arrangement of equipment in the cabinet as given in Section 3.6.2. Further details can be found in Catalogs NV21 and ET1.

Ambient Temperature in o C

55

50

40

1

30

2

3

20

200	400	600	800	1000	1200	1400 W
					Power Dissipation

1Closed cabinet with heat exchanger of size 11/6 (920 x 460 x 111 mm)

2Cabinet with through-ventilation by natural convection

3Closed cabinet with natural convection and forced circulation using fan

Figure 3-16 Maximum Cabinet Ambient Temperature as a Function of Power Dissipation

Note

When fitting the subracks of the S5-135U/155U series, the maximum power dissipation which can be removed by the fans must not be exceeded. The maximum removable power dissipation per unit with a supply air temperature of 55 °C is 250 W. This value is increased by 20 W for each reduction in supply air temperature by 1 °C.

System Manual	3-37
C79000-G8576-C199-06