Protectorelay® oil burner control provides automatic, non-recycling control of intermittent ignition oil burner system. Controls oil burner, oil valve (if desired) and ignition transformer in response to call for heat. Solid state flame sensing circuit. LED on terminal strip indicates system lockout. Remote lockout indication available on some models. Enclosed safety switch with external reset button. Manual trip lever opens safety switch for system maintenance. Mounts on standard 4 x 4-inch junction box; select models may be mounted directly on burner housing. C554A cadmium sulfide flame detector and 24-volt (AC) thermostat required.