Winding is a part of the motor. Embrittlement, moisture regain, heat, erosion, invasion of dirty things, impact of external force are all harmful to the winding. Motor load, under working voltage, overvoltage and open phase operation can also cause winding faults. Winding fault is generally divided into winding grounding, short circuit fault, lead, wiring is not correct. Nowadays, it shows the phenomenon, causes and query methods of the problem.

　　Refers to the winding and core or shell insulation damage caused by grounding.

　　1. Construction elevator motor fault phenomenon

　　The induction power on of the shell, the uncontrollable operation route, the short circuit fault of the winding, and the scalding caused the motor unable to operate normally.

　　2. Cause analysis of construction elevator motor

　　The results show that the insulation resistance is reduced due to winding moisture regain; the motor operates under long-term load; the harmful substances are eroded; the metal material dirt invades the inside of the winding and destroys the insulation; when rewinding the stator winding, the insulation damages the iron core; the top of the winding touches the bearing end cover of the motor shaft; the insulation burns due to the friction between the stator and the motor rotor; the insulation damages of the transformer grounding wire collides with the shell; the insulation damages the stator winding and the bearing end cover; Over voltage (e.g. lightning strike) causes the insulation to penetrate.

　　3. Construction elevator motor inquiry method

　　(1) investigation method. After estimating the winding top and the insulation in the wire slot, investigate whether there is any harm and black mark, if there is, it is the grounding address.

　　(2) digital multimeter inquiry method. If the reading value is not large, it is grounded.

　　(3) megohmmeter method. According to the different levels, the megohmmeter is used to measure the insulation resistance of each group of resistors. If the reading value is zero, it means that the winding is grounded. However, for the motor insulation to return to moisture or penetration due to safety accidents, it needs to be judged according to personal experience. Generally, if the meter needle hesitates at "0", it can feel that it has a certain resistance value.

　　(4) lamp test method. If the test lamp is on, it indicates that the winding is grounded. If a certain point is found to be accompanied by fire or smoke, it is the fault point of winding grounding. If the light is slightly on, the insulation has grounding penetration. If the light is not on, but when the detection rod is grounded, it also shows fire, indicating that the winding does not penetrate, but it is not optimistic. You can also use mahogany to knock on the edge of the end of the casing. When you knock on a certain place, when it turns off and lights up, it indicates that the current is on and off, then this point is the grounding address.

　　(5) current through burning method. With a transformer, after connecting the switching power supply, the connection address will be hot quickly, and the place where the insulation smokes is the connection address. In case of abnormality, it should be noted that small and medium-sized motors should not exceed twice the rated voltage, and the time should not exceed 30 seconds; large motors should be 20% - 50% of the rated voltage or slowly increase the current, and the power should be turned off immediately when the grounding address starts to smoke.

　　(6) sorting out method. The iron core of the transformer is burned together with the iron core of the transformer. The method adopted is to divide one phase winding into two parts, and so on to find the grounding address.

　　In addition, there are also high-voltage experiment method, magnetic probe method, DC oscillation method, etc., which are introduced in detail here.

　　4. Construction elevator motor solutions

　　(1) if the winding turns damp and causes grounding, it should be air dried. When it is cooled to 60-70 ℃, it should be air dried after pouring insulating paint.

　　(2) when the insulation at the top of the winding is damaged, the insulation shall be carried out from the beginning at the grounding point, painted and dried.

　　(3) when the winding grounding address is in the slot, rewind the winding or replace some winding components.