(1) Check the oil mark to confirm the suitability of the oil level;

(2) Check whether the coupling and cooler piping are connected correctly;

(3) Check the electrical wiring of the instrument is connected correctly;

(4) Check whether the coupling and the shield are properly installed;

(5) Check the coupling oil tank is appropriate, when the oil temperature is below 5 ℃, the electric heater should work oil heating;

(6) Check whether the coupler catheter is adjusted to the lowest rotational speed device