Ndioyenera kuchita muyeso wa kukana kwa insulation (IR), mayamwidwe chiŵerengero (DAR), polarization index (PI), leakage current (Ix) ndi mayamwidwe capacitance (Cx) mitundu yonse ya zida voteji mkulu, kuphatikizapo switchgear, thiransifoma, ma reactors, capacitors, motors, jenereta ndi zingwe, etc.