1.No Display on Power-Up

Cause: External power supply not connected.
Solution: Check and connect the external power supply.

2.No Start Signal and Start Indicator Off After Power-Up

Cause: Control terminal has no start signal.
Solution: Ensure the start signal is applied to the control terminal.

3.Bypass Contactor Fails to Actuate

Cause: Peripheral circuit failure or the operation terminal on the control board is inactive.
Solution: Check the peripheral circuit and operation terminal connections.

4.Tripping After Bypass

Cause: Bypass contactor cannot maintain self-holding or thermal relay protection.
Solution: Inspect the bypass contactor and thermal relay settings.

5.Short Circuit Protection Triggered
Causes:

(1)Bypass contactor not fully disengaged.

(2)Phase loss in power supply.

(3)Thyristor (SCR) short circuit.

(4)Filter board breakdown and short circuit.

Symptoms: Motor emits a buzzing sound or attempts to start when powered.
Solution: Check and repair or replace the bypass contactor, SCRs, or filter board.

6.Incomplete Startup and Fault Displayed

Cause: Excessive load or insufficient startup time.
Solution: Reduce the load or increase the startup time setting.

7.Thyristor Short Circuit

Cause: Overvoltage, overcurrent, or load phase loss.
Solution: Identify and address the cause of overvoltage, overcurrent, or phase loss.

8.Thermal Relay Trips During Operation
Cause:

i.Excessive dust on the heat sink.

Ii.Fan malfunction.

Iii.High current.

Solution:

1)Clean the heat sink with compressed air after disconnecting power.

2)Repair or replace the fan.

3)Reduce current to within the rated value.

9.Motor Vibration or Noise When Controlled by Soft Starter

Solution:

1.Check and replace the SCRs.

2.Replace the control board.

3.Inspect motor and wiring.

10.Abnormal Noise During Motor Startup and Operation

Inspection Steps:

1.Check for loose connections in the thyristor/module trigger wires.

2.Inspect the bypass contactor for damage or poor contact.

3.Ensure no phase loss in the power or load side.

4.Verify correct and appropriate parameter settings.

11.Motor Overload Tripping During Startup (Overload Indicator On)

Causes and Solutions:

(1)Improper overload adjustment: Reset overload settings.

(2)Excessive motor load: Reduce motor load.

(3)Low current limit setting: Increase the current limit.

(4)Incorrect startup adjustment: Reconfigure startup parameters.

12.Thermal Relay Trips During Operation (Overheat Indicator On)

Causes and Solutions:

1.Excessive dust on heat sink: Clean with compressed air after disconnecting power.

2.Fan malfunction: Replace the fan if powered; check power supply if not.

3.Excessive current: Ensure operating current does not exceed the rated value.

4.High ambient temperature: Relocate to a cooler environment (below 50°C for panel type, below 40°C for enclosed type).

5.Frequent startups: Avoid frequent starts to prevent SCR overheating.