Interstate Electrical Supply Inc., Columbus, Ga., has joined Affiliated Distributors (AD), Wayne, Pa. In addition to its Columbus headquarters, Interstate Electrical Supply has branches in LaGrange, Ga.; Auburn, Ala.; and Montgomery, Ala. Founded in 1972, Interstate Electrical Supply serves the commercial and industrial markets focusing on OEM’s, manufacturing facilities and contractors. The company’s automation department provides on-site training, technical support and programming services to their complete customer base, as well as UL-rated panel manufacturing. A-D now has 450-plus independently owned distributor members span seven industries and two countries with annual sales in excess of $20 Billion.