The motor manufacturer reminds that when the capacity of the high-power motor is relatively large, the starting current will cause a sharp drop in the grid voltage, which will affect the normal operation of other equipment on the grid.Therefore, generally for high-power motors with a power higher than 110KW, the motor manufacturer initiated the recovery of soft-start utilization, because during soft-starting, the starting current is generally 2 to 3 times the rated current, and the grid voltage fluctuation rate is generally within 10%. The impact of the equipment is very small, and the normal operation of the equipment under the same power grid can be guaranteed.

　　When other high-power motors are started at full voltage, they will damage the motor insulation and reduce the life of the high-power motors. The following are the reasons that the motor manufacturers have arranged.

　　①The heat generated by the large current is repeatedly impregnated into the outer insulation of the wire, which accelerates the aging of the insulation of the high-power motor and reduces the service life. ②The machine force generated by the large current causes the wires to rub against each other, which reduces the insulation life. ③When the high-voltage switch is closed, the chattering phenomenon of the contacts will cause manipulation overvoltage on the stator windings of the high-power motor, sometimes reaching more than 5 times the applied voltage. Such high overvoltage will cause great damage to the motor insulation.When soft-starting, the maximum current drops by about half, and the instantaneous fever is only about 1/4 of straight-up, and the insulation life will be greatly delayed; when soft-starting, the high-power motor terminal voltage can be adjusted from zero, which can completely avoid over-voltage damage. .

　　Full-voltage startup will cause damage to the machinery and equipment. Large currents will cause great attack on the motor stator coils and rotor squirrel cage bars, which will cause loose clamping, coil deformation, and squirrel cage bar breakage.During soft start, the attack power is greatly reduced due to the small maximum current.The starting torque during full-pressure direct starting is about twice the rated torque. Such a large moment is suddenly added to stationary machinery and equipment, which will accelerate gear wear or even toothing, accelerate belt wear and even break the belt, and speed up the fan blades. Tired and even broken wind leaves and so on.The torque of the soft start will not be higher than the rated torque, and the above-mentioned loopholes can be completely overcome.