N.C. Gen. Stat. § 160A-69

The mayor shall preside at all council meetings, but shall have the right to vote only when there are equal numbers of votes in the affirmative and in the negative. In a city where the mayor is elected by the council from among its membership, and the city charter makes no provision as to the right of the mayor to vote, he shall have the right to vote as a council member on all matters before the council, but shall have no right to break a tie vote in which he participated.