Combined light and power systems for industrial plants

THE upward trend in illumination levels in industrial plants has resulted in an increased power demand of the lighting load. Illumination levels of 50 foot-candles are in general considered good practice at the present time, with some thinking of illumination levels as high as 100 foot-candles. The lighting load is a sizable portion of the total plant load. In many average manufacturing plants the lighting load will represent 2 to 4 volt-amperes per square foot, and the power load 8 to 10 volt-amperes per square foot. The same technique that has been applied in distributing power to machine tools and other power loads will pay dividends in distributing power to the lighting load.