used in coal mine well; with kinds protective functions; with related safe,explosion-proof certificates PurposeQBZ-2 × 120 (80) ... hours can be troubleshooting; 2. Fans with dual-supply, dual automatic switching function; 3. Starter with overload, short-circuit, breaking phase ... less voltage, over-voltage protection, and other functions; 4. With the motor at all levels of power, operation, maintenance, ...