Specifications

Application Examples Softstart UK
10.5. DC Brake with External Zero Speed Sensor
For loads which may vary between braking cycles, there are benefits in using an external zero-speed sensor to
interface with the LV-DS for brake shut-off. This control method ensures that the LV-DS braking will always
shut off when the motor has reached a standstill, thus avoiding unnecessary motor heating.
The following schematic diagram shows how you can use a zero-speed sensor with the LV-DS to turn the brake
function off at motor standstill. The zero-speed sensor (A2) is often referred to as an under-speed detector.
Its internal contact is open at zero-speed and closed at any speed above zero-speed. Once the motor has
reached a standstill, 53, 55 will open and the starter will be disabled. When the next start command is given
(ie next application of KA1), 53, 55 closes and the LV-DS is enabled.
The LV-DS must be operated in remote mode and parameter 6D Input A Function must be set to 'Starter
Disable'.
12789.B
-
F
1
L
3
L
2
L
1
N
E
-KA1
L1
L2
L
3 E
T1
T2 T3
A
5A
4
A6
54
5
5 5
6 5
7
58
53
55
-
KA
1-
K
A2
-
KA
1
-K
A
2
T3
T
2T
1
M
3
-
KA
2
-K
A1
-A2
1
Control voltage
A
Off (Ready)
54, 55
Start
B
Start
56, 57
Stop
C
Run
58, 57
Reset
D
Stop
2
Motor terminals
E
Zero speed
3
Three-phase supply
5
Start signal (2, 3, or 4-wire)
4
Starter Disable (shown on starter display)
6
Zero speed sensor
For details on configuring DC Brake, see Brake (page 29).
CAUTION
When using DC brake, the mains supply must be connected to the soft starter (input terminals L1, L2,
L3) in positive phase sequence and parameter 4B Phase Sequence must be set to Positive Only.
54/64 710-15797-00A – LV-DS User Manual