Power Calculations

—To compute the horse power required to raise a given quantity of water to a certain height, multiply the gallons per minute by 8.35, and this product by the height in feet; the result will be the work done in foot pounds. To reduce this to horse power per minute, divide by 33,000. Usually, an allowance of 50 per cent. is made for friction and other lo . To estimate the electrical energy required to deliver an electric load, multiply the amperes by the voltage, the product will be the total number of watts. An electrical horse power is 746 watts, therefore, divide the total number of watts by 746 and the result will be the electrical horse power. To ascertain the brake horse power of an engine when direct connected to generator, multiply the amperes by the voltage and divide by 660; the result will be the approximate brake horse power of the engine. If the engine is of the belted type, divide the total number of watts by 550 instead of 660. In computing the horse power it is customary to allow ten 16 candle power lights to the horse power. A 16 candle power light is equal to 55 watts.