The Application of 2400 V to Longwall Face Equipment

Typical face widths of longwall mining installations in the U.S. range from 500 to 750 ft and are usually operated at a utilization voltage of 995 V. Since the introduction of longwall mining in the U.S., continuous developments and improvements of face equipment have occurred, and there is a trend toward high-capacity longwalls with face widths up to 1000 ft. This evolution of longwall equipment, which has resulted in a significant increases in horsepower requirements, has reached a point where the adequacy of 995 V as an efficient utilization voltage is questionable. Thus higher utilization voltages, such as 2400 V, are more appropriate. Some operational aspects of systems at both voltages are compared with the additional safety criteria used to meet Mine Safety and Health Administration (MSHA) requirements for the safe application of 2400 V.