S1 Threshold Switch - Siemens SINAMICS S120 Equipment Manual

8.1.3.7

S1 Threshold switch

The response threshold at which the Braking Module is activated and the DC-link voltage
generated during braking are specified in the following table.
Electric shock when the threshold switch switches
Operating the threshold switch when a voltage is present can cause death or serious injury.
• Only use the threshold switch when the Basic Line, Smart Line, Active Line, or Motor
Table 8- 3
3 AC 380 ...
3 AC 500 ...
3 AC 660 ...
Air-cooled chassis power units
Manual, 07/2019, 6SL3097-4AE00-0BP9
WARNING
Module are switched off and the DC link capacitors are discharged.
Response thresholds of the Braking Modules
Voltage Response
threshold
673 V
480 V
774 V
841 V
600 V
967 V
1070 V
690 V
1158 V
Switch Remark
position
1 774 V is the default factory setting. For line voltages of
between 3 AC 380 V and 400 V, the response threshold
2
can be set to 673 V to reduce the voltage stress on the
motor and converter. This does, however, reduce the
possible braking power with the square of the voltage
(673/774)² = 0.75.
The maximum possible braking power is therefore 75%.
1 967 V is the default factory setting. With a supply voltage
of 3 AC 500 V, the response threshold can be set to 841
2
V to reduce the voltage stress on the motor and convert-
er. This does, however, reduce the possible braking
power with the square of the voltage (841/967)² = 0.75.
The maximum possible braking power is therefore 75%.
1 1158 V is the default factory setting. With a supply volt-
age of 3 AC 660 V, 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.
The maximum possible braking power is therefore 85%.
DC link components
8.1 Braking Module
329