The　single　phase　autoreclosure　is　often　used　to　improve　the　reliability　and　stability　of　power　grid　in　EHV　transmission　lines.　The　connection　of　shunt　reactor　and　neutral　reactor　is　normally　used　to　extinguish　arc　and　to　ensure　success　of　autoreclosure.　Calculation　and　analysis　results　show　that　the　neutral　reactor　can　maintain　a　low　voltage　at　the　fault　location　that　makes　arc　easily　extinguishing,　but　make　it　difficult　to　assess　the　level　of　insulation　that　makes　reclosing　within　the　fault　line.　To　avoid　failure　of　reclosure,　a　breaker　between　the　neutral　point　and　grounding　point　can　be　used.　The　breaker　can　be　closed　before　reclosure,　then　the　voltage　of　the　fault　line　can　be　used　to　assess　the　insulation　level　of　this　line.