Lub tshuab hluav taws xob hluav taws xob yog lub kaw lus tsim los ntawm cov khoom siv hluav taws xob thiab kev xa tawm thiab kev xa tawm uas tsim hluav taws xob thiab cov khoom siv thiab xa mus rau cov khoom siv hluav taws xob. Lub tshuab fais fab tuaj yeem faib ua peb hom: TN, IT, thiab TT. TN system tau muab faib ua peb hom: TN-C, TN-S, thiab TN-CS.
