Recently, a question came up regarding installing overcurrent protection for dry-type transformers rated less than 1,000 volts (V). The transformer installation is a 150-kilovolt-ampere, three-phase unit with a 480V primary and a 208Y/120V secondary.
Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to email@example.com. Answers are based on the 2014 NEC. Unsupported raceways