Overload protection is widely used in machinery, metallurgy, building materials, chemicals, textile industry. For three-phase (single-phase) motors, And other Electrical appliances current protection and monitoring.When the current of the circuit is abnormal, It will cut off the current to protect the safety of motor use.
Overload protection overcurrent sensing material is: "bimetal."  It consists of bimetallic thermal elements, Action mechanism, Normally open normally closed contact, Reset button and so on. When the motor is overloaded, The current becomes large, Overload protection will lead to switch tripping, Thus plays the certain protection to the electrical machinery the function.
Motor overload protection includes: Short circuit protection, Lack of phase protection, Phase imbalance protection, Wrong phase protection