Important Safety Precautions - Siemens SINAMICS S120 Manual

This block diagram shows the DC interface embedded in a Cabinet Module in chassis
format. Frame sizes FX and GX each contain two fuses, while frame size JX contains four
fuses. Depending on the current carrying capacity, frame size HX contains either two or four
fuses.
Four pre-charging resistors are also used in frame size JX for higher power ratings. For more
detailed information, see the circuit diagrams.
The circuit diagram shows the wiring without additional options.
Note
With option K90 (Control Unit), a checkback contact is wired from terminal -X41:12 to digital
input 3 on customer terminal block -X55 to commission the DC interface via parameter
interconnection (see "Commissioning the DC interface"). A jumper to the reference potential
is also used.
8.25.3.1

Important safety precautions

The Motor Module can be serviced after it has been disconnected from the DC busbar via
the DC interface and after the capacitor discharge time has elapsed. However, the following
safety precautions must be observed:
Once the DC busbar and the Motor Module have been disconnected using the DC interface
(-Q7), the following voltages may be present in the Cabinet Module:
• Up to 1200 V on the DC busbar (protected against accidental contact)
• Line voltage (3 AC 380 V ... 480 V or 500 V ... 690 V) on the auxiliary power supply
• Up to 230 V AC on the optional mounting locations
• 24 V DC on the auxiliary power supply system (electronics power supply)
• On motor connection -X2 (e.g. regenerative voltage due to residual speed)
The cabinet units are operated with high voltages.
All connection work must be carried out when the cabinet is de-energized.
All work on the cabinet must be carried out by trained personnel only.
Work on an open cabinet must be carried out with extreme caution because external supply
voltages may be present. The power and control terminals may be live even when the
motor is not running.
Due to the DC link capacitors, dangerously high voltage levels are still present inside the
cabinet up to 5 minutes after it has been disconnected. For this reason, the cabinet should
not be opened until a reasonable period of time has elapsed.
For this reason, you must take the following safety precautions when carrying out work on
the Cabinet Module after the DC interface has been switched off:
Cabinet Modules
Manual, (GH5), 05/2010, A5E03263538A
8.25 L37, DC interface incl. pre-charging input circuit for the relevant DC link capacitance
DANGER
system or 2 AC 230 V downstream of the transformers for the fan supply
WARNING
Options
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