N.C. Gen. Stat. § 62-23

The Commission is hereby declared to be an administrative board or agency of the General Assembly created for the principal purpose of carrying out the administration and enforcement of this Chapter, and for the promulgation of rules and regulations and fixing utility rates pursuant to such administration; and in carrying out such purpose, the Commission shall assume the initiative in performing its duties and responsibilities in securing to the people of the State an efficient and economic system of public utilities in the same manner as commissions and administrative boards generally. In proceedings in which the Commission is exercising functions judicial in nature, it shall act in a judicial capacity as provided in G.S. 62-60. The Commission shall separate its administrative or executive functions, its rule making functions, and its functions judicial in nature to such extent as it deems practical and advisable in the public interest.