Protective Circuitry For The Brake - Siemens SINAMICS S120 Configuration Manual

6.3.5

Protective circuitry for the brake

Caution
In order to avoid overvoltages when shutting down and the possible negative impact on
the plant or system environment, a protective circuit must be integrated into the brake feeder
cable (refer to Fig. "Recommended circuit for the external power supply with protective
circuit").
If protective circuitry is not used, voltage peaks over 1000 V can occur in the millisecond
range. Brake solenoid, switching contacts and electronic components could be destroyed.
Sensitive electronic components (e.g. logic components) can even be damaged as a result
of a lower switch-off voltage. The power limits (e.g. ratings) of the components used should
be carefully observed.
Figure 6-4
Table 6-13
Electr.
component
F
K1
R2
Synchronous Motors 1FK7
Configuration Manual, (PFK7S), Edition 12.2006, 6SN1197-0AD16-0BP1
Recommended circuit for the external power supply with protective circuit
Example Electronic components for the recommended circuit
3RV10 circuit-breaker with current
paths connected in series (if required
with mounted auxiliary contact
3RV1901 to provide a feedback signal
for the drive).
Auxiliary contactor 3RH11
Varistor SIOVS14K30 (EPCOS)
6.3 Holding brake (option)
Examples
or Miniature circuit-breaker 5SX21
(if required with mounted auxiliary
contact to provide a feedback signal for
the drive).
or Contactor 3RT10
Motor components
81