Dc Interface, Principle Of Operation; Commissioning The Dc Interface With Option K90/K91 - Siemens SINAMICS S120 Equipment Manual

NOTICE
You must observe the applicable legal regulations when carrying out all work.
The following voltages are normally present on the auxiliary voltage busbar system:
• 380 to 480 V 2 AC for fan supply
• 230 V 1 AC
• 24 V DC for electronics power supply
If you have installed an additional auxiliary voltage busbar system (option K75), hazardous
voltage levels may also be present here. This busbar is protected against accidental
contact.
8.20.3.2

DC interface, principle of operation

The DC interface connects/disconnects the DC busbar and the Motor Module in the Cabinet
Kit. This option is implemented with a pre-charging input circuit. A fuse switch disconnector,
which is installed as a standard feature between the Motor Module and the DC busbar, as
well as pre-charging resistors and contactor disconnectors connect the Motor Module with
the DC busbar.
The contactor disconnector is triggered via a time relay, which is activated by the switch
installed in the door.
The DC interface should only be switched and the fuse switch disconnector should only be
unplugged when not under load. A checkback signal is passed via the internal
interconnection to the CU320 Control Unit which locks out switching under load.
8.20.3.3

Commissioning the DC interface with option K90/K91

With option K90/K91, a checkback contact from the fuse switch disconnector is factory-linked
to digital input 3 of the Control Unit.
CAUTION
If changes are made to the factory-set parameters, you must verify that the "Infeed ready"
checkback signal is connected to digital input 3 on the Control Unit (p0864 = r722.3).
If parameter p0864 is not wired to the checkback signal, it is possible to operate the switch
under load. This can shorten the service life of the switch.
S120 Cabinet Modules Equipment Manual
Manual, (GH5), 10/2008, A5E00427098A
8.20 L37, DC interface incl. pre-charging input circuit for the relevant DC link capacitance
DANGER
CAUTION
Options
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