S.C. Code Ann. § 58-3-21: Subsistence allowance.

While hearing cases or any other matter within the commission's jurisdiction or on other official business outside the county in which he resides, within fifty miles of his residence, a public service commissioner is entitled to a subsistence allowance in the amount of thirty-five dollars per day plus such mileage allowance for travel as is provided for other employees of the State. While hearing cases or any other matter within the commission's jurisdiction or on other official business at a location fifty miles or more from his residence, a public service commissioner is entitled to a subsistence allowance in the amount as provided for members of the General Assembly plus such mileage allowance for travel as is provided for other employees of the State.