Important Safety Precautions - Siemens SINAMICS S120 Equipment Manual

Options
8.20 L37, DC interface incl. pre-charging input circuit for the relevant DC link capacitance
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/K91 (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.
8.20.2.1

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 (380 to 480 V 3 AC or 500 to 690 V 3 AC) on the auxiliary voltage busbar
• Up to 230 V AC on the optional mounting locations
• 24 V DC on the auxiliary voltage busbar 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 five minutes after it has been disconnected. For this reason, the cabinet
should not be opened until a reasonable period of time has elapsed.
384
DANGER
system or 230 V 2 AC downstream of the transformers for the fan supply
WARNING
S120 Cabinet Modules Equipment Manual
Manual, (GH5), 10/2008, A5E00427098A