The protection methods of DC motor are described from five aspects: over-voltage protection, zero excitation protection, overload protection, over-current protection and grounding protection.

There are five ways to protect DC motor

(1) Overvoltage protection: a kind of armature circuit protection composed of overvoltage relay;

(2) Zero excitation protection: the excitation circuit protection composed of current relay;

(3) Overload protection of DC motor: a kind of armature circuit protection composed of current relay;

(4) Over current protection of DC decelerating motor: the protection of armature circuit composed of over current relay;

(5) Grounding protection: the grounding protection is composed of voltage relay. When any point of DC deceleration motor is grounded, the voltage relay acts to send out warning signal or cut off the power supply of DC deceleration motor.