S.C. Code § 48-9-1220
Effective November, 1982, and in November of the appropriate years thereafter, three commissioners from each district must be elected. The election must be nonpartisan and must be conducted by the county election commission at the same time as other county officers are elected in the general election.
To be placed on the ballot for county offices, each candidate shall submit to the county election commission a nominating petition with the signatures of one hundred qualified registered electors or one percent of the qualified registered electors of the district, whichever is lesser.
The nominees in the petition must be placed on the appropriate official ballot for the election if the petition is submitted to the county election commission not later than twelve noon on July fifteenth or, if July fifteenth falls on Sunday, no later than twelve noon on the following Monday. The form of the petition must comply with the requirements in Section 7-11-80 pertaining to the conduct of general elections not conflicting with this section. Candidates must be qualified registered electors and residents of the district in which elected.
The three candidates who receive the largest number of votes cast in the election are elected and shall assume office the following February first.
This election must be conducted pursuant to Title 7, mutatis mutandis, except as otherwise provided for in this section.
Effective with the 1990 election, the two candidates who receive the highest number of votes shall serve for terms of four years each and the other candidate who receives the next highest number of votes shall serve for a term of two years. Thereafter, their successors must be elected in a nonpartisan election to be held at the same time as the general election for terms of four years each.
S.C. Code § 48-9-1220