S1 Threshold Switch - Siemens SINAMICS S120 Manual

5.1.3.7

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.
Actuate threshold switch only when device is turned off
The threshold switch must only be used when the Basic Line, Smart Line, Active Line, or
Motor Module are switched off and the DC-link capacitors are discharged.
Table 5- 3
3 AC 380 ...
3 AC 500 ...
3 AC 660 ...
Chassis power units
Manual, (GH3), 01/2013, 6SL3097-4AE00-0BP3
WARNING
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
converter. 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
voltage of 3 AC 660 V, the response threshold can be set
2
to 1070 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
(1070/1158)² = 0.85.
The maximum possible braking power is therefore 85%.
DC link components
5.1 Braking Module
225