Whakakīhia te rerenga e whai ake nei: E whakamahia ana ngā pūrongo SER e ngā kaipūkaha hiko ki te tātari i ngā pōturi nui me te iti o te pūnaha hiko. I muri i te
Te ngoikore o te raki-rawhiti o te tau 2003, i whakatauhia e te North American Electric Reliability Corporation (NERC) me wa-tohu nga raraunga punaha hiko ki te millisecond tata.