Fans; Differential-Pressure Switch; Surge Suppressor; Door Limit Switches - Siemens SINAMICS GL150 Operating And Installation Instructions

Description
3.3 Power unit
3.3.2.7

Fans

The fan is mounted on the cabinet. The fan draws in air through the ventilation slots in the door
from the immediate vicinity of the cabinet. The fan blows the air radially into the ambient area.
A contactor and a motor protection switch protect the fan against overload.
3.3.2.8

Differential-pressure switch

The differential-pressure switch monitors the independent air cooling and the associated fans.
The operating range lies between 100 and 1000 Pa. The differential-pressure switch measures
the pressure drop across the heat sink elements. The pressure drop is then compared with
the set response threshold. When the fans are in operation and draw the required volumetric
flow through the heat sink elements, the response threshold must have been exceeded.
See also
Replacing the differential pressure monitor (Page 122)
3.3.2.9

Surge suppressor

Overvoltages can occur when inductive loads are switched, for example, in the case of
transformer disconnections at no load. These overvoltages can pose a danger to the converter.
In indoor systems, spark-gap-free surge suppressors made of metal oxide are used to limit
the overvoltages. They are connected as follows:
● Between the phases in a star
● From that star point to ground
3.3.2.10

Door limit switches

Door limit switches monitor the doors or the cover of the power unit. When a door or a cover
is opened, the converter is switched off and the circuit breaker opened.
Note
Door limit switches are used for monitoring, but do not provide a protection function.
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SINAMICS GL150 6SL38503UM114PA0Z
Operating Instructions 04/2017