[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: 30CFR75.311]

[Page 470]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 75--MANDATORY SAFETY STANDARDS--UNDERGROUND COAL MINES--Table of Contents
 
                         Subpart D--Ventilation
 
Sec. 75.311  Main mine fan operation.

    (a) Main mine fans shall be continuously operated, except as 
otherwise approved in the ventilation plan, or when intentionally 
stopped for testing of automatic closing doors and automatic fan signal 
devices, maintenance or adjustment of the fan, or to perform maintenance 
or repair work underground that cannot otherwise be made while the fan 
is operating.
    (b) Except as provided in paragraph (c) of this section, when a main 
mine fan is intentionally stopped and the ventilating quantity provided 
by the fan is not maintained by a back-up fan system--
    (1) Only persons necessary to evaluate the effect of the fan 
stoppage or restart, or to perform maintenance or repair work that 
cannot otherwise be made while the fan is operating, shall be permitted 
underground;
    (2) Mechanized equipment shall be shut off before stopping the fan; 
and
    (3) Electric power circuits entering underground areas of the mine 
shall be deenergized.
    (c) When a back-up fan system is used that does not provide the 
ventilating quantity provided by the main mine fan, persons may be 
permitted in the mine and electric power circuits may be energized as 
specified in the approved ventilation plan.
    (d) If an unusual variance in the mine ventilation pressure is 
observed, or if an electrical or mechanical deficiency of a main mine 
fan is detected, the mine foreman or equivalent mine official, or in the 
absence of the mine foreman or equivalent mine official, a designated 
certified person acting for the mine foreman or equivalent mine official 
shall be notified immediately, and appropriate action or repairs shall 
be instituted promptly.
    (e) While persons are underground, a responsible person designated 
by the operator shall always be at a surface location where each main 
mine fan signal can be seen or heard.
    (f) The area within 100 feet of main mine fans and intake air 
openings shall be kept free of combustible material, unless alternative 
precautions necessary to provide protection from fire or other products 
of combustion are approved in the ventilation plan.
    (g) If multiple mine fans are used, the mine ventilation system 
shall be designed and maintained to eliminate areas without air 
movement.
    (h) Any atmospheric monitoring system operated during fan stoppages 
shall be intrinsically safe.