Nowadays, as the electric power executive equipment, although some of the motors have been controlled by frequency converter, this kind of situation mostly exists in the environment with high regulation accuracy requirements. In general work, we mostly use three-phase asynchronous motor which generally uses motor integrated protector.

I. classification of motor comprehensive protector:

At present, three-phase asynchronous motor comprehensive protector can be divided into two categories: Ordinary electronic type and intelligent type.

(1) general electronic protector generally includes three kinds of protection functions: overload, short circuit and leakage.

(2) the intelligent motor comprehensive protector takes the advanced single-chip microcomputer as the core device, and its protection function is divided into many parts, including: overload, short circuit, leakage, insulation monitoring, over / under voltage, lack of equal items.

(3) for the specific setting of various parameters of general electronic or intelligent motor comprehensive protector, the corresponding operation manual shall be referred to. Attention shall be paid to electrical safety during installation and commissioning, and appropriate protectors shall be selected according to the actual situation.

II. Functions of motor integrated protector:

Protection function: in addition to general protection function, it also has self starting, communication starting and closing, and under current, over voltage, under voltage, three-phase current imbalance, self starting and other functions are acceptable to users.

Setting function: intelligent type has setting key, data key and shift key. When the setting is out of range, it will remind the user to reset to avoid misoperation. The basic type is set by dialing code or potential apparatus.

Alarm function: when the over-current light of three-phase asynchronous motor flashes, the larger the over-current multiple is, the faster the flash is, or the contact external alarm of the protector is used

Display function: after the protector is powered on, press the setting key to display the whole current value, and press the data key to display the three-phase current value. After startup, the fault code is displayed and the corresponding fault indicator is on, which is clear at a glance.

Communication function: realize information transmission through serial digital interface, one PC can connect 256 protectors, and can set parameters for each motor, start and stop operation, convenient for automatic management.