Three-phase asynchronous motor winding fault analysis and processing

Winding is part and parcel of the motors,aging,be affected with damp be affected with

damp,heat,erosion,foreign bodies,intrusion,the impact of the external force can cause damage to

winding,motor overload,under voltage,over voltage,lack of phase operation can also cause winding fault.Winding grounding,short circuit,open circuit fault generally fall into winding,connection errors.Now separately failure phenomena,causes and inspection method.A,winding grounding Winding to close or with insulation casing damage caused by the grounding.1,failure phenomenon Chassis charged,heat control circuit is out of control,winding short circuit,the normal operation of the motor.2,the reason Winding be affected with damp be affected with damp decreased insulation resistance;Motor overload for a long time;The harmful gas corrosion;Metal foreign body into winding internal damage insulation;Rewind stator winding insulation damage when touch the core;Winding end touch end cover frame;Set,rotor friction caused insulation burns;Lead wire insulation damage into the shell;Overvoltage (such as lightning) insulation breakdown.Methods to examine 

3.(1) the method of observation.magnet prices Through visual winding overhang and line slot

insulation observed with and without damage and charred traces,is the pick up location.(2) the

multimeter test.The multimeter low-resistance archives check,reading is very small,it is grounded.(3) megohmmeter.Selected according to different levels of different measuring each group resistance of insulation resistance by megger are,if the reading www.dongfeng-motor.com is zero,then the winding grounding,but the motor insulation be affected with damp be affected with damp or breakdown due to accident,must determine on the basis of experience,generally pointer swing timing in "0" place,its have certain resistance value can be thought of.(4) try to light.If try lights,winding grounding,if found somewhere with a spark or smoke,is the place for winding grounding fault point.If lights dim the insulated grounding breakdown.If rotor and stator the light is not bright,but also showed a spark when the test stick ground,winding yet breakdown,just seriously be affected with damp be affected with damp.Also can use hardwood on the edge of the shell of the seam allowance tapping,to a certain place when a out a bright,when electrical current when broken,it is ground.

(5) current wear burning method.With a regulating transformer,after the power is connected,ground quickly heating and insulation smoke is the pick up location.Should pay special

attention to small motor shall not be more than twice the rated current,no more than half a

minute;Big motor as 20% - 20% of rated current or increasing current,burning to ac motor wind generator the ground just immediately without electricity.(6) packet elimination method.For the pick up location in iron core and burning more severe,in my heart burning loss of copper and iron core melt together.Approach is to put the grounding of one phase winding is divided into two and a half,and so on,finally find out the ground.In addition,there are high voltage testing method,magnetic exploration method,power frequency vibration method,etc.,differ a introduced here.4.The processing method (1) winding drying should be affected with damp be affected with damp cause ground,when cooled to about 60-70 ℃,pour insulating paint again after drying.(2) the end winding insulation damage,in receiving is located in the back of the insulation and painting,dry again.(3) windings to place in the groove,should rewind or replace part windings components.Finally apply different measured by megger,meet the technical requirements.