CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH (parts 56 to 58) > PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES > SUBPART T—Safety Standards for Methane in Metal and Nonmetal Mines (§57.22001 to §57.22608) > 57.22309—Methane monitors (V-A mines).

57.22309—Methane monitors (V-A mines).

(a) Methane monitors shall be installed on continuous mining machines used in or beyond the last open crosscut.
(b) The monitors shall—
(1) Give warning at 1.0 percent methane.
(2) Automatically deenergize electrical equipment, except power to monitoring equipment determined by MSHA to be intrinsically safe under 30 CFR part 18, and prevent starting of such equipment when methane levels reach 1.5 percent; and
(3) Automatically deenergize the equipment when power to a sensor is interrupted.
(c) Sensing units of monitors shall be positioned at a location which provides for the most effective measurement of methane.