[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: 30CFR18.29]

[Page 95]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 18--ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES--Table of Contents
 
             Subpart B--Construction and Design Requirements
 
Sec. 18.29  Access openings and covers, including unused lead-entrance holes.

    (a) Access openings in explosion-proof enclosures will be permitted 
only where necessary for maintenance of internal parts such as motor 
brushes and fuses.
    (b) Covers for access openings shall meet the same requirements as 
any other part of an enclosure except that threaded covers shall be 
secured against loosening, preferably with screws having heads requiring 
a special tool. (See Figure 1 in Appendix II.)
    (c) Holes in enclosures that are provided for lead entrances but 
which are not in use shall be closed with metal plugs secured by spot 
welding, brazing, or equivalent. (See Figure 10 in Appendix II.)