General Information On Ventilation - Siemens SINAMICS S120 Manual

Cabinet design
6.11 Notes on control cabinet cooling
6.11.2

General information on ventilation

SINAMICS components are force-ventilated using integrated fans, and in some cases
through natural convection. The fans are not equipped with temperature-dependent speed
control; only the states "on" or "off" exist.
Fan operation up to firmware version 2.5
The fans are switched on and off as a function of the heat sink temperature.
The fans start up at a specific heat sink temperature for the particular device. They switch
themselves off with a small hysteresis as soon as the heat sink temperature falls below this
threshold. The run-on time of the fan depends on various factors such as ambient
temperature, output current, duty cycle and, therefore, cannot be determined directly.
Fan operation as of firmware version 2.6
The fans can be controlled as a function of the heat sink temperature.
The fans start up at a specific heat sink temperature for the particular device – or when a
pulse enable is set. They switch themselves off with a small hysteresis as soon as the heat
sink temperature drops below the stored temperature value and there is no pulse enable.
The fan run-on time can be parameterized (see SINAMICS S120/S150 List Manual).
Air guidance
The cooling air must flow through the components vertically from bottom (cooler region) to
top (region heated by operation).
If filter fans, heat exchangers, or air conditioners are used, you must ensure that the air is
flowing in the right direction. You must also ensure that the warm air can escape at the top.
A ventilation clearance of at least 80 mm at the top and bottom must be provided.
NOTICE
Damage caused by overheating resulting from covered ventilation slots
Covered ventilation slots can cause the system to overheat. This can damage components.
• Route the connected signal and power cables to the components in such a way that
Note
The distance between the discharge opening of the air conditioner and the electronic
equipment must be at least 200 mm.
Note
If the components are mounted in a sealed cabinet, an internal air cooling system must be
installed to circulate the air and prevent hot spots. It is best to mount the fan above the
components so that air is sucked up from the bottom of the cabinet to provide an optimized
air flow.
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they do not cover the ventilation slots.
Power Units in Booksize C/D-Type Format
Manual, 12/2018, 6SL3097-5AC20-0BP0