Siemens SINAMICS S120 Manual page 488

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8.32 L37, DC interface incl. pre-charging input circuit for the relevant DC link capacitance
Hazardous electrical voltage
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:
● Observe the "five safety rules" for all electrical work.
● Only commission qualified specialists to carry out the work.
● Ensure that no voltage is present at the measuring points provided in the cabinet.
● Check that there is no voltage on the motor connections.
● When working close to the DC busbar in the cabinet, take care to avoid any contact with
● When replacing components, make sure that no screws or small parts fall into the
● Remove the fan fuse and fuse for the 24 V DC power supply
Note
Compliance with legal regulations
You must observe the applicable legal regulations when carrying out all work!
Hazardous electrical voltage
The following voltages are normally present on the auxiliary power supply system:
 380 to 480 V 2 ph. AC for fan supply
 230 V 1 AC
 24 V DC for electronics power supply
486
WARNING
the DC busbar!
cabinet.
DANGER
Cabinet Modules
Manual, 03/2013, A5E03263538A