Siemens SIMOTICS S-1FK7 DYA Generation 2 Operating Instructions Manual page 67

Note
Integrate a protective circuit into the incoming cable. In this way, you avoid switching
overvoltages and possible influence of the installation environment. See the figure below
A
K1
F
S1
R2
Figure 6-5
Table 6- 1 Example: Electrical components for the suggested circuit
Electrical
component
F 3RV10 circuit-breaker with current paths
connected in series (if required with mounted
auxiliary contact 3RV1901 to provide a feed-
back signal for the drive).
K1 Auxiliary contactor 3RH11
R2 Varistor SIOVS14K30 (EPCOS)
S-1FK7 DYA G2 synchronous motors with planetary gearbox
Operating Instructions, 05/2018, A5E44881183B AA
Motor
Contactor
Circuit-breaker
Holding brake
Varistors
Suggested circuit for the external power supply with protective circuit
Examples
or Miniature circuit-breaker 5SX21 (if required with
mounted auxiliary contact to provide a feedback
signal for the drive).
or Contactor 3RT10
Connecting
6.4 System integration
65