The 17 entrants performed four separate one-hour challenges, including wiring and programming lighting controllers as part of the Master Electricians Challenge.
The top 10 competitors get the chance to go through to the national championships next month.
Otago co-ordinator Neville Dreaver said the competition was designed to ''foster the best and brightest young electricians''.
To qualify for the challenge, apprentices must have at least 20 months' on-the-job experience, have completed their level 2 ''off-job'' training and still have been an apprentice on March 1.
Master Electricians operations manager Bernie McLaughlin said the apprentices could face any task an electrician might encounter in the course of their day-to-day work.
''The scenarios are designed to test that they can respond swiftly and efficiently to challenging tasks they may face in their working life.''
Mr Dreaver said Otago electricians had fared ''pretty well'' at the national championships in the past, including placing first and second ''three or four years ago''.
About 100 entrants are expected to take part in the regional heats nationwide. The national final will be held in Hamilton from May 26-28.
