(1) Qhov cuam tshuam ntawm qhov kub, qhov kub muaj qhov cuam tshuam zoo rau qhov rwb thaiv tsev tsis kam, thiab rwb thaiv tsev tsis kam poob thaum kub nce. Qhov laj thawj yog vim tias qhov kub nce siab, kev sib tsoo ntawm cov kab hluav taws xob insulating qhov nruab nrab nce, thiab qhov nce ntawm hluav taws xob kev coj ua rau lub rwb thaiv qhov tsis kam txo qis. Qhov laj thawj ntawm qhov kev hloov pauv yog cuam tshuam nrog cov qib kev hloov qhov kub thiab lub ntuj thiab cov qauv ntawm cov khoom siv insulating.
(2) Qhov cuam tshuam los ntawm cov av noo, av noo muaj ntau dua los cuam tshuam rau ntawm qhov chaw xau tam sim no, vim tias cov nplaim insulating nqus kom ya raws thiab ua rau cov yeeb yaj kiab dej, uas yuav txo tau cov rwb thaiv tsev tsis kam.
(3) Deterioration tshwm sim los ntawm cov tshuab insulator.
(4) Lub hygroscopicity ntawm porcelain qhov chaw zuj zus.
(5) Kev sib tshooj ntawm kev ntxhov siab sab hauv thiab sab nraud ntawm cov khoom seem hauv plooj.
(6) Kev txiav tawm qhov teeb meem los ntawm cov cua sov nthuav tawm ntawm cov hluav taws xob cov plooj (insulators).
(7) The saturation expansion ntawm steel cap pouring cement puas zus.
(8) Qhov khov ntawm khov ntawm cov hlau cap hliv cov cement zuj zus.
(9) Qhov hluav taws xob tsis zoo ntawm cov hlau cap thiab cov taw hlau cuam tshuam.
(10) Deterioration los ntawm insulator overvoltage.
(11) Kev tsis meej los ntawm kev ua haujlwm sab hauv nyob hauv lub rwb thaiv tsev.