Mobile equipment means equipment that is self-propelled. MSHA means the United States Department of Labor, Mine Safety and Health Administration. Normal operation means the regular performance of those functions for which a machine or accessory was designed. L. 91-173, as amended by Pub. Permit means a formal document, signed by the Assistant Secretary, authorizing the operation of specific experimental equipment in a gassy mine or tunnel under prescribed conditions.
Plane joint means two adjoining surfaces in parallel planes.
Portable cable, or trailing cable means a flame-resistant, flexible cable or cord through which electrical energy is transmitted to a permissible machine or accessory. Portable equipment means equipment that may be moved frequently and is constructed or mounted to facilitate such movement. Potted component means a component that is entirely embedded in a solidified insulating material within an enclosure. Pressure piling means the development of abnormal pressure as a result of accelerated rate of burning of a gas-air mixture. Qualified representative means a person authorized by MSHA to determine whether the applicable requirements of this part have been complied with in the original manufacture, rebuilding, or repairing of equipment for which approval, certification, or a permit is sought.