Abstract: A luminaire diagnostic system including a lamp and a photocontroller for automatically turning the lamp on during periods of darkness and off during periods of daylight wherein the photocontroller includes detector circuitry for detecting the load drawn by the lamp, a microprocessor, responsive to detected load and programmed to predict a condition of the lamp such as a cycling event and/or lamp out condition based on the load drawn by the lamp, and an indicator such as a visual alarm for indicating the occurrence of the condition detected and/or a transmitter for transmitting the detected condition to a remote location. Also, upon cycle detection, the lamp may be turned off to prevent damage to fixture components.