Siemens SINAMICS S120 - DC Interface, Principle of Operation

Options
8.28 L37, DC interface incl. pre-charging input circuit for the relevant DC link capacitance
Cabinet Modules NEMA
Manual, 04/2014, A5E03586450A
453
Figure 8-40 Measuring point, 24 V DC auxiliary power supply, frame sizes FX and GX
Take into account additional voltages from options and refer to the circuit diagrams.
8.28.3.4
DC interface, principle of operation
Table 8- 46 DC interface, principle of operation
Switch setting
Meaning
Result/Comments
0 Switching contacts are open Neither the pre-charging section nor the main
charging section are switched in.
Pre-charging DC interface is switched to
PRECHARGE.
DC link capacitors are loaded.
Pre-charging remains activated
until the ON command is is-
sued.
The pre-charging section is switched to the DC
link busbar (the main section remains switched
off).
Once the unit is switched on with the ON com-
mand, the Motor Module unlocks the DC inter-
face and moves it into the operating position.
1 Switching contacts are closed The DC interface switches to position "1".
When the DC switch is in the operating posi-
tion, the connected auxiliary contacts are
switched.
The required auxiliary supply voltage is provided via the auxiliary power supply system. To
ensure that this functions properly, a digital input must be interconnected during
commissioning. Like all the other required connections, it is pre-wired in the cabinet.
If any signals are required (e.g. for checkback purposes or for activating other units), two
switching contacts can be used. Two normally-open contacts (NO) are available here for use
as required. The contacts switch in "Pre-charging" (contacts 53, 54) or "Operation" position
(contacts 63, 64). The auxiliary contacts can be loaded with a maximum of 3 A.