[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR27.24]

[Page 145]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 27--METHANE-MONITORING SYSTEMS--Table of Contents
 
             Subpart B--Construction and Design Requirements
 
Sec. 27.24  Power-shutoff component.

    (a) A power-shutoff component shall be suitably constructed for 
incorporation in or with permissible and approved equipment that is 
operated in gassy mines and tunnels.
    (b) The power-shutoff component shall include:
    (1) A means which shall be made to function automatically to 
deenergize the machine or equipment when actuated by the methane 
detector at a methane concentration of 2.0 volume percent and at all 
higher concentrations in the mine atmosphere.
    (i) For an electric-powered machine or equipment energized by means 
of a trailing cable, the power-shutoff component shall, when actuated by 
the methane detector, cause a control circuit to shut down the machine 
or equipment on which it is installed; or it shall cause a control 
circuit to deenergize both the machine or equipment and the trailing 
cable.
    Note: It is not necessary that power be controlled both at the 
machine and at the outby end of the trailing cable.
    (ii) For a battery-powered machine or equipment, the methane-monitor 
power-shutoff component shall, when actuated by the methane detector, 
cause a control circuit to deenergize the machine or equipment as near 
as possible to the battery terminals.
    (iii) For a diesel-powered machine or equipment, the power-shutoff 
component, when actuated by the methane detector, shall shut down the 
prime mover and deenergize all electrical components of the machine or 
equipment. Batteries are to be disconnected as near as possible to the 
battery terminals. Headlights which are approved under Part 20 of this 
subchapter (Schedule 10, or any revision thereof) are specifically 
exempted from this requirement.
    (2) An arrangement for testing the power-shutoff characteristic to 
determine whether the power-shutoff component is functioning properly.