a. PurposesQBZ-200,120,80/1140(660,380)Z mine explosion-proof intelligent (reversible) vacuum electromagnetic starter is ideal for use in AC 50Hz, rated voltage≤1140V power supply network without neutral line directly grounded, in coal mines with methane compound gases and dangerous explosive gases for on-spot control or remote control on 3-phase squirrel cage asynchronous motors. Therefore, when it is attached in KJ2000 mine electric power automatic control and comprehensive measurement and monitor system to realize automatic control on power supply equipments in mining area and that no person on duty is necessary.b. Protective functions1. Backlight LCD display for real-time display of 3-phase current, situa   tions of faults etc;2. Rated current can be modified and adjusted by 3-bit code-dialing switch,    and step length is 1;3. The starter has protective functions of short-circuit, overload, phase loss,    3-phase unbalance and cu