Siemens SINAMICS S120 Equipment Manual page 188

DC link components
5.1 Braking Module
Table 5- 3
380 V - 480 V
500 V - 600 V
660 V - 690 V
Note
The switch positions of the threshold switches of the Braking Modules are positioned on the
panel as follows:
• Braking Modules for frame sizes FX, FB, GX, GB: Position "1" is at the top; position "2" is
• Braking Modules for frame sizes HX and JX: Position "1" is at the back; position "2" is at
CAUTION
Even when the response threshold is set to a low value, the DC link voltage can still reach
the maximum voltage value (hardware shutdown threshold), thus triggering the
"Overvoltage" fault. This can occur, for example, in cases where there is too much
regenerative energy for the available braking power.
To prevent the DC link voltage from exceeding the threshold, the Vdc-max controller must
be enabled (p1240) and the device supply voltage set accordingly (p0210).
188
Response thresholds of the Braking Modules
Voltage Response
threshold
673 V
3 AC
774 V
841 V
3 AC
967 V
1070 V
3 AC
1158 V
at the bottom
the front
Switch Remark
position
1 774 V is the default factory setting. With supply voltages
of between 380 V and 400 V 3 AC, the response
2
threshold 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 500 V 3 AC, the response threshold can be set to
2
841 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 660 V 3 AC, 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%.
Manual, (GH3), 10/2008, 6SL3097-2AE00-0BP3
Chassis power units