The 4131 is cUL and UL listed single phase SCP power control panel. It provides a simple-to-install solution for adding an SCR to an existing heater control system. The panels are a Chromalox model MaxPac I, MaxPac II or MaxPac III in an Enclosure. Since SCRs generate heat, the panel is ventilated and fan cooled to allow the selected MaxPac controller to operate at 100% output with and ambient of 40°C (104°F).