(1) Structural characteristics

　　① The explosion-proof vacuum electromagnetic starter for mining is composed of an explosion-proof shell and a vacuum AC contactor, isolation switch, step-down transformer, program component, relay component, circuit conversion component, button component, terminal block, and electronic motor comprehensive protection (JDB) installed inside. There is a mechanical interlock between the operating handle and the stop button of the phase change isolation switch. The isolation switch handle can only rotate when the stop button is pressed, and the door cover can only be opened when the isolation switch handle is placed in the "disconnect" position by the interlock rod.

　　② The shell of the mining explosion-proof vacuum electromagnetic starter is divided into two independent explosion-proof parts: the junction box and the main chamber. A handle, button, and interlocking screw are installed on the right side of the main chamber. The handle is used to connect and disconnect the power supply of the main circuit, and to switch the motor. In addition, the handle, button, and interlocking screw cooperate with each other for electrical and mechanical interlocking Ensure that the large cover of the casing can only be opened when the vacuum contactor and isolation switch are in the predetermined disconnection position. In addition, there is an observation window for fault indication on the door cover, which has a similar appearance to the above product, with dimensions of 582mmX520mmX800mm (length X width X height).

　　③ The mining explosion-proof vacuum electromagnetic starter consists of a steel plate and a shell welded with stainless steel, as well as a body installed inside the shell. The body is equipped with a vacuum AC contactor with long service life, strong breaking ability, frequent operation, and no exposed arc. It also has a reversing isolation switch with certain breaking ability, which can change direction when there is no load (but can rotate the isolation switch handle to break the circuit in emergency situations), JDB motor comprehensive protector (D type) with overload, short circuit, phase failure, and leakage protection, or JR9-300 current limiting thermal relay (R type) with overload and short circuit protection and other components. The upper part of the shell is a wiring cavity, which is used for introducing and extracting cables through a conduit.

　　(2) Purpose:

　　① The BQD4-80~315 mining explosion-proof vacuum electromagnetic starter is mainly used in places where coal mine components contain explosive gases (methane, coal dust mixture) In the 50Hz AC line with voltage up to 1140V (BQD4-80, 120, 200 voltage up to 660V), the three-phase stepper motor is directly started and stopped, and the motor and its related circuits are protected in the forward direction.

　　② The explosion-proof vacuum electromagnetic rear actuator for mining is suitable for places containing explosive gases (methane, coal dust mixture) in coal mines. It can be used as a three-phase stepper motor for on-site or remote control of AC 50Hz and voltage up to 660V to directly start, stop, and reverse direction. The starter H is equipped with protection systems such as overvoltage, overvoltage, phase failure, short circuit, and leakage lockout, while displaying faults through light-emitting diodes. In addition, the product has the function of exchanging JR9 thermal relay and JDB electronic comprehensive protector, which can be selected by state households.

　　③ The mining insulation vacuum electromagnetic starter is suitable for places containing explosive gases (methane, coal dust mixture) underground in coal mines. It can be used as a local or remote control for starting, stopping, and reversing three-phase stepper motors with AC 50Hz and voltage up to 660V when there is no load. It has protection functions such as overvoltage, overload, phase failure, short circuit, and leakage lockout. This series of starters is particularly suitable for frequent operation and heavy load coal mining machinery equipment.