APC Step-Down Transformer RM 2U 208V IN 120V OUT; w/5-20 Receptacles. APC Step-Down Transformer , Input: 208V , Input Connections: NEMA L6-30P , Output: 120V , Output Connections: NEMA 5-20R. The Step-Down Transformer converts high voltage (208 or 200 VAC) output into low voltage (120 or 100 VAC) output for powering low voltage AC equipment.