SPD(Pūrere Ārai Ngaru, parenga ngaru) e whakamahia ana hei ārai i te ngaohiko tere e puta mai ana i ngā whiunga uira, i ngā mahi whakawhiti whatunga rānei, kei kino ngā taputapu. He rerekē ngā utu me ngā wāhi e tika ana mō ngā SPDS i hangaia mai i ngā rauemi me ngā hanganga rerekē.

Ko te wāhanga matua o te SPD ko te konutea waikura varistor (MOV), he iti te utu, ā, he tere te urupare. He whānuitia te whakamahinga mō te tiaki i ngā whare noho, ngā whare arumoni, ngā kāpata tohatoha me ngā taputapu ahumahi. Ko te utu mō te momo MOV SPD mō te tohatoha ngaohiko iti noa kei waenganui i ngā tekau ki ngā rau yuan.

He nui te kaha kawe iahiko me te mahi whakamahana o ngā ngongo tuku hau (GDT) a te SPD, ā, he pai hoki mō te tiaki i ngā raina iahiko ngoikore i roto i ngā teihana turanga whakawhitiwhiti kōrero, ngā pokapū raraunga, ngā pūnaha haumarutanga, me ētahi atu. He nui ake te utu i tērā o ngā hua MOV noa.

Ka whakamahia e ngā hua SPD papai te hanganga whakakotahitanga MOV+GDT. Kei ētahi hua anō hoki ngā taputapu whakamahana, ngā tohu hapa me ngā mahi whakaoho mamao, e whakarato ana i te haumaru me te pono teitei ake. He pai mō ngā wāhi nui pēnei i ngā hōhipera, ngā pūnaha hiko, te waka tereina, ngā teihana hiko photovoltaic me ngā pūnaha whakahaere aunoatanga ahumahi, ā, ko ngā utu kei waenga i ngā rau ki ngā mano yuan.

Mō ngā whare tari noa, ngā whare noho me ngā toa, ka taea te whiriwhiri i ngā momo SPDS MOV paerewa. Mō ngā wāhi he maha ngā mahi uira, ngā rūma whakawhitiwhiti kōrero, ngā pokapū raraunga me ngā kaupapa ahumahi nui, e taunakihia ana kia whiriwhiria ngā SPDS whakakotahi, ngā SPDS kaha-auau nui rānei hei whakarei ake i ngā āheinga tiaki uira me te tiaki ngaohiko nui o te pūnaha, me te whakarite kia roa te mahi pumau o ngā taputapu.

.