Control of the lubrication pump duty cycle by the host PLC: running time and interval. The longest working time of lubrication pump is ≤2min, the shortest interval time is ≥2min. there is a relief valve to prevent the lubrication pump working pressure overload, there is a current overload protection tube to ensure the safe work of lubrication pump. Equipped with low oil level alarm signal output. The motor is equipped with an overheat protector to protect the safe working of the motor.