Criteria for approval of mining equipment incorporating on-board switching of high-voltage circuits

The US Mine Safety and Health Administration (MSHA) recently developed criteria to modify the current regulation prohibiting the on-board switching of high-voltage circuits (>1000 V AC). Extensive research conducted by the US Bureau of Mines and MSHA provided the basis for the development of safe and viable criteria. Under the provisions of Title 30 Code of Federal Regulations, Section 18.82, experimental permits were issued to high-voltage continuous miners and longwall systems incorporating this new technology. The information gathered from the operation of this equipment in the field along with industry concerns and recommendations were considered during the finalization of these criteria