Types Of Cabinet; Clearances In Cabinets - Siemens S5-135U/155U System Manual

Installation Guidelines
3.7.1

Types 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
Heat removal primarily Increased heat removal
by natural thermal through increased air
convection, small movement
portion via the cabinet
wall
Type of protect. IP 20 Type of protect. IP 20
Typical removable power dissipation under the following boundary conditions:
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)
*
The location and ambient conditions are decisive for selection of the type of cabinet protection
(
**
For other temperature differences, refer to the temperature characteristics of the cabinet
manufacturer.
3.7.2

Clearances 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:
3-34
Natural convection
Heat removal only
through the cabinet
wall; only low power
dissipation permissible.
Heat accumulation
usually occurs in the
top of the cabinet.
Type of protect. IP 54
Up to 260 W
see IEC 529 and DIN 40050).
The expansion units can be accommodated with the respective central
controller in one cabinet, or in two or more cabinets (centralized or
distributed).
On 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.
Closed Cabinets
Forced circulation Forced circulation
using fan assembly, using heat exchanger,
external ventilation
enhanced natural
convection inside and outside
Heat removal only via Heat removal through
the cabinet wall. Forced exchange between
ventilation of the heated internal air and
internal air results in cool outside air. The
improved heat removal increased surface of the
and prevention of heat folded-area sectional
accumulation. wall of the heat
exchanger and forced
circulation of internal
and external air permit
good heat output.
Type of protect. IP 54 Type of protect. IP 54
Up to 360 W Up to 1700 W
System Manual
C79000-G8576-C199-06