In industrial production, motor soft starters are widely used for their ability to smoothly start motors and protect equipment. However, in some scenarios, soft starters may trip after a period of time, affecting production progress. Below, Sanchang Intelligence will analyze possible reasons based on common factors.

1. Unreasonable parameter settings for the soft starter

The starting time, current limit and other parameters of the soft starter need to be matched with the motor. If the starting time is set too short and the motor fails to reach the rated speed smoothly, the starting current will continue to be in a high state, exceeding the protection threshold of the soft starter, which will trigger overload protection and cause tripping. In addition, if the current limit parameter is set too low, the actual current of the motor may exceed the limit value when starting with load, which can also cause tripping. In this case, it is necessary to readjust the relevant parameters of the soft starter according to the rated power and load characteristics of the motor.

2. Excessive motor load

If the load exceeds the rated load during motor operation, it will cause an increase in motor current. After the soft starter starts the motor, the current of the motor continues to be high during heavy load operation. When it exceeds the overload protection setting value of the soft starter and reaches the protection time, the soft starter will activate the protection mechanism, cut off the circuit, and achieve tripping. At this point, it is necessary to check the load carried by the motor to see if there are any mechanical blockages or abnormal load increases, and adjust the load to a reasonable range in a timely manner.

3. Poor heat dissipation of soft starter

During the operation of the soft starter, heat will be generated. If the cooling fan fails, the cooling holes are blocked by dust, or the installation environment has poor ventilation conditions, the heat cannot be dissipated in a timely manner, which will cause the temperature of the internal components of the soft starter to rise. When the temperature exceeds the set overheat protection value, the soft starter will automatically trip to protect its own components. Regularly clean the dust from the cooling holes of the soft starter and check the operation status of the cooling fan to ensure smooth cooling channels.

4. There is a malfunction in the motor or circuit

Damage to the insulation of the motor winding can cause inter turn short circuits, resulting in an abnormal increase in the motor's operating current. The soft starter will trip upon detecting the abnormal current. In addition, if there is poor contact or aging or damaged cables between the motor and the soft starter, it can cause an increase in line resistance, generate additional heat, cause line overload, and ultimately cause the soft starter to trip. It is necessary to test the insulation of the motor winding, the connection status of the circuit, and the integrity of the cables, identify and repair faults.

5. Unstable power supply voltage

The operation of the motor has certain requirements for the power supply voltage. If the power supply voltage fluctuates too much, such as too low, the current will increase to maintain normal speed when the motor starts and runs; If the voltage is too high, it will exacerbate the loss of internal components in the motor and may also cause abnormal current. When the current exceeds the protection range of the soft starter, a tripping phenomenon will occur. Real time monitoring of power supply voltage can be achieved through voltage monitoring equipment, and if necessary, a voltage regulator can be configured to stabilize the voltage.

The above are common reasons for motor tripping after a period of soft start. In practical situations, it is necessary to comprehensively investigate various factors such as the operating status and parameter settings of the on-site equipment. Sanchang Intelligent has rich experience in the field of motor control equipment. If enterprises encounter problems related to motor soft start troubleshooting or equipment selection, they can consult for professional technical support to ensure stable operation of the equipment.