Ko te pīhi DC he taputapu i hangaia hei tiaki i ngā ara iahiko hiko mai i ngā kino i puta mai i te nui o te iahiko, e puta mai ana i te taumaha rawa, i te ara iahiko poto rānei. He momo taputapu haumaru hiko e whakamahia ana i roto i ngā pūnaha hiko DC (iahiko tika) hei tiaki i ngā iahiko nui me ngā ara iahiko poto.
He rite ngā fiusi DC ki ngā fiusi AC, engari he mea hanga motuhake mō te whakamahi i roto i ngā ara iahiko DC. Ko te tikanga he mea hanga mai i te konganuku kawe hiko, he koranu rānei, he mea hanga hei whakarewa me te whakakore i te ara iahiko ina neke atu te iahiko i tētahi taumata. Kei roto i te fiusi he rīpene angiangi, he waea rānei e mahi ana hei wāhanga kawe hiko, e puritia ana e tētahi hanganga tautoko, ā, e mau ana i roto i tētahi anga tiaki. Ina neke atu te iahiko e rere ana i roto i te fiusi i te uara kua whakatauria, ka wera te wāhanga kawe hiko, ā, ka rewa, ka pakaru te ara iahiko, ka whakakore hoki i te rere o te iahiko.
He whānuitia ngā whakamahinga o ngā fiusi DC, tae atu ki ngā pūnaha hiko o ngā motuka me ngā waka rererangi, ngā panera rā, ngā pūnaha pākahiko, me ētahi atu pūnaha hiko DC. He āhuatanga haumaru nui ēnei hei āwhina i te tiaki i ngā ahi hiko me ētahi atu tūponotanga.