Brief Introduction

The starting principle of a DC pump drive motor is the same as that of an AC motor. When a DC motor starts, it should also meet two basic requirements:

(1) It must have a sufficiently large starting torque;

(2) The starting current cannot exceed the safe range.At the moment the DC pump motor is started, the rotor has not yet rotated, and the reverse potential has not yet been established (E=0), that is, it is directly started at the rated voltage. At this time, the starting current is I st=U/R A.Since the resistance R a of the DC motor armature winding is very small, the start-up current I st is very large, generally as high as 10 to 20 times the rated current I n, which seriously exceeds the start-up current requirements for motor commutation.At the same time, excessive armature current will inevitably produce a large starting torque, causing the motor and the machinery it is dragging to suddenly suffer a huge impact, thereby damaging the pump drive motor, transmission mechanism and production machinery.

Therefore, the size of the starting current must be limited.Generally, the method of connecting the start-up transformer (multi-stage start-up) in series in the armature circuit is used to limit the start-up current, so that the start-up current I st= (1.5～2.5) I N.

Main Technical Parameters