Siemens S5-135U/155U Types of Cabinet, Clearances in Cabinets, Open Cabinets, Closed Cabinets

Installation Guidelines

3.7.1Types of Cabinet

The following table provides on overview of the most common types of cabinet. It also shows the principle of heat removal, as well as the estimated, maximum achievable power loss removal and the type of protection* .

Open Cabinets

Through-ventilation by	Increased
natural convection	through-ventilation

Natural convection

Closed Cabinets

Forced circulation using fan assembly, enhanced natural convection

Forced circulation using heat exchanger, external ventilation inside and outside

Heat removal primarily by natural thermal convection, small portion via the cabinet wall

Increased heat removal through increased air movement

Heat removal only through the cabinet wall; only low power dissipation permissible. Heat accumulation usually occurs in the top of the cabinet.

Heat removal only via the cabinet wall. Forced ventilation of the internal air results in improved heat removal and prevention of heat accumulation.

Heat removal through exchange between heated internal air and cool outside air. The increased surface of the folded-area sectional wall of the heat exchanger and forced circulation of internal and external air permit good heat output.

Type of protect. IP 20

Type of protect. IP 20

Type of protect. IP 54

Type of protect. IP 54

Type of protect. IP 54

Typical removable power dissipation under the following boundary conditions:

S S

Cabinet size 2200 x 600 x 600 mm

Temperature difference between external and internal temperature of the cabinet: 20 °C**

Up to 700 W

Up to 2700 W (1400 W with very fine filter)

Up to 260 W

Up to 360 W

Up to 1700 W

*The location and ambient conditions are decisive for selection of the type of cabinet protection

(Õ see IEC 529 and DIN 40050).

**For other temperature differences, refer to the temperature characteristics of the cabinet manufacturer.

3.7.2Clearances in Cabinets

You must first define the components to be fitted in the cabinet. Then calculate the total power dissipation of the individual components. The following stipulations must be observed:

SThe expansion units can be accommodated with the respective central controller in one cabinet, or in two or more cabinets (centralized or distributed).

SOn account of the required clearances and maximum permissible installation height for control elements, a maximum of three SIMATIC S5 devices can be arranged one above the other.

3-34	System Manual
	C79000-G8576-C199-06