Specifications

Softstart UK Application Examples
10.6. Soft Braking
For applications with high inertia and/or a variable load, the LV-DS can be configured for soft braking.
In this application the LV-DS is employed with forward run and braking contactors. When the LV-DS receives a
start signal (pushbutton S1), it closes the forward run contactor (KM1) and controls the motor according to the
programmed primary motor settings.
When the LV-DS receives a stop signal (pushbutton S2), it opens the forward run contactor (KM1) and closes
the braking contactor (KM2) after a delay of approximately 2-3 seconds (KT1). KA3 is also closed to activate the
secondary motor settings, which should be user programmed for the desired stopping performance
characteristics.
When motor speed approaches zero, the zero speed sensor (A2) stops the soft starter and opens the braking
contactor (KM2).
3
6
5
3
5
6
1
2
3
4
1
Control voltage
A2
Zero speed sensor
2
Remote control inputs
KA1
Run relay
3
Motor thermistor input
KA2
Start relay
4
Relay outputs
KA3
Brake relay
5
Three-phase supply
KA4
Zero speed sensor relay
6
Motor terminals
KM1
Line contactor (Run)
KM2
Line contactor (Brake)
KT1
Run delay timer
KT2
Brake delay timer
S1
Start contact
S2
Stop contact
S3
Reset contact
Parameter settings:
• Parameter 6D Input A Function (terminals 53, 55)
• Select 'Motor Set Select' - assigns Input A for Motor set selection.
• Set starting performance characteristics using the primary motor set.
• Set braking performance characteristics using the secondary motor settings.
• Parameter 7G Relay C Function
• Select 'Trip' - assigns Trip function to Relay Output C.
NOTE
If the LV-DS trips on supply frequency (parameter 16F Frequency) when the braking contactor KM2
opens, modify the frequency protection settings.
710-15797-00A – LV-DS User Manual 55/64