Siemens Low Voltage RP1 Unassembled Lighting Panel. Minimum Enclosure Dimensions (H x W x D) IN 74.0 x 20.0 x 5.75. 3-Phase 4-Wire allows 54 circuits user selects Main Device (Lug/Breaker). Rated xGB/3VA41 interior 480Y/277V (400A). Special features tin-plated copper main bus, subfeed space included