Activation Via Off Fault Responses; Activation Via A Speed Threshold - Siemens SINAMICS S120 Function Manual

Basic functions
7.11 Armature short-circuit, DC braking
7.11.2.3

Activation via OFF fault responses

Setting as a response to OFF fault signals
With p1231 = 5, DC braking is set as a response to OFF1 or OFF3. Parameter p1230 has no
influence on the response for OFF1/OFF3. The speed threshold is set with p1234, under
which DC braking is activated.
Activation using OFF1/OFF3
DC braking is activated with OFF1 or OFF3.
● If the motor speed ≥ p1234, the motor is braked down to p1234. As soon as the motor
speed is < p1234, the pulses are disabled and the motor is demagnetized.
● If the motor speed at OFF1/OFF3 is already < p1234, the pulses are immediately
inhibited and the motor is demagnetized.
DC braking is then activated for the duration p1233 and is then switched off.
When OFF1/OFF3 is prematurely canceled, then normal operation is resumed.
DC braking as emergency braking of a fault response remains active.
7.11.2.4

Activation via a speed threshold

Setting
If p1231 is set to 14, DC braking as a response is activated as soon as the actual speed falls
below p1234.
Activation
Before activation, the actual speed must be > p1234. DC braking can then be activated
when both of the following conditions are met:
● The actual speed has fallen below p1234.
● The signal source of p1230 is set to "1".
The pulses are first disabled. As a consequence, the motor is demagnetized. DC braking is
then initiated for the duration p1233. The motor is braked with the braking current p1232.
If the signal source of p1230 is set to "0", the braking command is canceled and the drive
goes back into the previous operating mode.
DC braking for OFF1 or OFF3 is only executed if the signal source of p1230 is set to "1".
DC braking as emergency braking of a fault response remains active.
308
Function Manual, (FH1), 04/2014, 6SL3097-4AB00-0BP4
Drive functions