I-TNSUlawulo lwe-voltage oluzenzekelayo oluchanekileyo oluphezulu olunezigaba ezintathu ludityaniswe nolawulo lwe-voltage oluzenzekelayo oluphezulu olunezigaba ezintathu lwe-TND(SVC), Amanqanaba amathathu ahlengahlengiswa ngokwahlukeneyo ukuqinisekisa i-voltage ekhuselekileyo eqinileyo kwisigaba ngasinye. Amandla angenayo enethiwekhi amanqanaba amathathu yinkqubo yeengcingo ezine, uqhagamshelo olufana neenkwenkwezi (Y), amandla okukhupha angenziwa kwizigaba ezintathu iingcingo ezine, amanqanaba amathathu eengcingo ezintathu, iimitha ezintathu ze-ampere zibonisa umbane wokuphuma kwisigaba ngasinye, ukuthintela i-volage yangaphandle yesigaba ngasinye nge-aswitch kunye notshintsho lwemitha ye-voltage.