Siemens SINAMICS S120 Manual page 269

Maintenance and servicing
6.1 Chapter content
This chapter provides information on the following:
● Maintenance and servicing procedures that have to be carried out on a regular basis to
● Replacing device components when the unit is serviced
● Forming the DC link capacitors
Hazardous electrical voltage
Before carrying out maintenance or repair work on the de-energized cabinet, wait for 5
minutes after switching off the power supply. This allows the capacitors to discharge to a
harmless level (< 25 V) after the line voltage has been switched off.
Before starting work, you should also measure the DC link voltage after the 5 minutes have
elapsed. The voltage can be measured on DC link terminals DCP and DCN.
Beware of any residual rotation of the fan.
External supply voltages
When the external power supply (e.g. option L55) or the external 230 V auxiliary infeed or
supply infeed is connected, dangerous voltages are still present in the cabinet even when
the main breaker is open.
Cabinet Modules
Manual, 03/2013, A5E03263538A
ensure the availability of the components
DANGER
DANGER
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