What is the impact of low grid voltage on soft starter? Electricians who have been debugging soft starter for 5 or 6 years often encounter this situation.
Then the soft starter should have primary power supply voltage and secondary control voltage. Now many soft starter manufacturers have extracted the control voltage from the soft starter. If the control voltage is too low, the main control board of the soft starter will stop working, so that the whole machine of the soft starter will stop and the motor will stop. If the control voltage is too low, the bypass contactor of soft starter can not be closed, and sometimes the contactor will vibrate repeatedly. If only the control voltage is too low, users can take voltage stabilizing measures to solve the problem. And the primary voltage is too low. In general, when the motor does not rotate, the voltage is normal. When the soft starter starts the motor, the primary voltage drops sharply, generally to 70% of the rated voltage. For heavy load, it can not start at all, so the motor will have a long time of high current until the soft starter fault protection. The main causes of low primary voltage are transformer capacity and cable length and quality. Specific problems should be solved. In a word, stable voltage is the foundation for soft starter to work normally.
