Threshold Switch - Siemens SINAMICS G150 Operating Instructions Manual

Electrical installation
4.10 Other connections
Duty cycles
Figure 4-25
4.10.11.3

Threshold switch

The response threshold at which the braking unit is activated and the DC link voltage
generated during braking are specified in the following table.
Danger to life due to electric shock when operating threshold switches
Operating the threshold switch when a voltage is present can cause death or serious injury.
• Only operate the threshold switch when the cabinet unit is switched off and the DC link
Table 4- 39
Rated voltage
3 AC 660 ...
138
Duty cycles for the braking resistors
WARNING
capacitors are discharged.
Response thresholds of the braking units
Response
threshold
1070 V
690 V
1158 V
Switch Comment
position
1 1158 V is the default factory setting. With a supply volt-
age of 660 V 3 AC, the response threshold can be set to
2
1070 V to reduce the voltage stress on the motor and
converter. This does, however, reduce the possible brak-
ing power with the square of the voltage (1070/1158)² =
0.85.
Therefore, the maximum possible braking power is 85 %.
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A