ʻO nā kaula uila haʻahaʻa he mau uwila uila i hoʻolālā ʻia e hana ma nā volts haʻahaʻa ma mua o 1000 volts, ma lalo o 1,000 volts AC a i ʻole 1,500 volts DC. Hoʻohana ʻia kēia mau kaula i nā ʻōnaehana mana e pono ai ka ikehu liʻiliʻi a hoʻohana maʻamau ʻia i ke kelepona, ka hoʻoili ʻikepili, a me nā ʻano palekana a me nā ʻōnaehana automation. ʻO nā pōmaikaʻi o nā kaula uila haʻahaʻa e pili ana i ka palekana i hoʻonui ʻia, hoʻemi ʻia ka pilikia o nā haʻalulu uila, a me ka pono o ka ikehu.