Chapter 2 Installation and Wiring
2.3 Wiring
The wiring of motor soft starter should be operated only by professionals
experienced in high and low voltage electric circuit and should read this
manual in detail before wiring.
2.3.1 Standard Wiring Diagram
Basic Wiring
Diagram
Circuit Breaker
(MCCB) or Leakage
Circuit Breaker
ELCB
Main Circuit
Bypass Magnetic Contactor
Full Voltage Output
Delay Output
(Programmable)
Failure Output
Control Circuit
RS485 COM
Analog Output
DC 0-20mA
Instantaneous Stop
Stop
Start
Common Port
Chapter 2 Installation and Wiring
2.3.2 Description of Main Circuit Terminals
Terminal Mark
Terminal Name
Functional Description
Main Circuit Input Terminal
Main Circuit Output Terminal
Bypass Connection
Ground Terminal
Connect to three-phase input power
supply.
Connect to three-phase electric motor.
Connect to bypass contactor
Soft starter cabinet ground terminal
1
Input Terminals (R, S, T)
Three-phase input power supply should be connected to the input terminals R, S
and T of the motor soft starter after it goes through the circuit breaker. Three-phase
power supply does not differ on phase sequence and can be arbitrarily connected.
While wiring, DO connect three-phase input power supply to the terminals R, S
and T. Otherwise, it may result in severe damage to the motor soft starter.
It is recommended not to shut down the machine by disconnecting the main circuit
power supply or install an electromagnetic contactor between the input terminals R,
S, T and the power supply to run or stop the motor soft starter. Do select RUN or
STOP keys on the operation panel or external control terminals to run or stop the
motor soft starter.
2
Output Terminals (U, V, W)
The output terminals U, V and W should be connected to the three-phase motor. If
the motor counter rotates (reverses), just change arbitrarily two phases of U, V and
W.
Do not install a capacitor or surge absorber between the output terminals U, V, W
and the three-phase motor. Otherwise, it may result in failure of the motor soft
starter or damage to the devices.
Too long connecting line between the motor and the motor soft starter may result
in overcurrent trip, increase of cutoff current, low accuracy of current display of the
motor soft starter. So, it is suggested to use a line not exceeding 50m.
3) Bypass Connection (L21, L22, L23)
The bypass connection terminals L21, L22 and L23 should be connected to the
electromagnetic contactor. No wrong connection or incorrect phase sequence!
When the starting of the soft starter is finished, the main loop power device (SCR)
will log out and the bypass electromagnetic contactor will run simultaneously. At this
time, the motor is brought into normal service.
4) Ground Terminal ( G)
The ground terminal of motor soft starter should be properly connected to the
ground to avoid electric shock or fire. The ground wire can not share a ground point
with any other strong current load. They must be connected respectively, and the
ground wire is the shorter the better
