How is a 15 amp 277 volt lighting circuit wired at the panel?

The voltage of 277 volts is the wye voltage of a three phase 480 volt distribution. In the 480 volt CDP (Central Distribution Panel), you will need a 600 volt rated single pole 15 amp breaker installed in the CDP. The load will be connected to the output terminal of the breaker and the other conductor will be connected to the neutral bus in the CDP. The minimum size conductor for the 15 amp circuit will be a #12 copper conductor.