Mining loads for central stations

The paper discusses the desirability of mining loads for central stations from the view points of both the mine operators and central station operators. The power supplied to a mine from a central station is used, in general, for haulage, hoisting, ventilation, coal cutting, pumping, tipples, machine shop, blacksmith shop, and general lighting. The power required for each of these services is briefly analyzed, and the types of motors for different services is indicated. The second part of the paper relates to rates for power supplied, and the various methods of rate making, such as flat rates, maximum demand system, flat rate with fixed charge, etc., are analyzed. The effect of power factor on rates and the methods of measurement of load are also considered. The paper concludes with some general suggestions in regard to power contracts.