57.22306—Methane monitors (I-A mines).
(a)
Methane monitors shall be installed on continuous mining machines, longwall mining systems, and on loading and haulage equipment used in or beyond the last open crosscut.
(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 such equipment when methane levels reach 1.5 percent. Diesel equipment shall be shut off or immediately removed from the affected area; and
(3)
Automatically deenergize electrical equipment when power to a sensor is interrupted. Diesel equipment shall not be operated if the monitor is inoperative.
(c)
Sensing units of monitors shall be positioned at a location which provides for the most effective measurement of methane.