Siemens SINAMICS S120 System Manual page 96

Braking Modules
7.1 Braking Module Booksize
Rapid discharge
Furthermore, the Braking Module Booksize can used with a braking resistor to quickly discharge
the DC link capacitors The DC link is discharged in a controlled manner via the braking resistor
once the infeed unit has been switched off and the line-up has been disconnected from the line
supply (e.g. via the main switch or line contactor). The function can be activated via a digital
input on the Braking Module. A quick discharge makes sense, for example, when maintenance
tasks are to be performed at the Motor Module and/or motor installation (reduction of the
discharge time).
Electric shock when live parts are touched after a rapid discharge
On completion of quick discharge, a voltage of 30 V is still present at the DC link. If the fast
discharge is interrupted before it has been completed, then this voltage can be more than 60 V.
Touching live components can result in death or severe injury.
• Check the DC link to ensure that it is in a no voltage state before starting any work.
NOTICE
Damage to equipment or motors in the event of rapid discharge
For a fast discharge, the Motor Module or the connected motors can be damaged.
• Ensure that all permanently excited synchronous motors are at a complete standstill, and
Monitoring functions
• Automatic detection of braking resistors and braking power monitoring
• I
• Temperature monitoring of the Braking Module
• Short circuit and overload detection
• Ground fault detection
94
WARNING
that the drive system is completely disconnected from the supply system before activating
the rapid discharge.
t monitoring of the braking resistors.
2
High Frequency Drive
System Manual, 10/2020, 6SL3097-5AH10-0BP0