[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR77]

[Page 643]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 77_MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK 
AREAS OF UNDERGROUND COAL MINES--Table of Contents
 
                           Subpart H_Grounding
 
Sec.  77.701-1  Approved methods of grounding of equipment receiving power 
from ungrounded alternating current power systems.

    For purposes of grounding metallic frames, casings and other 
enclosures of equipment receiving power from ungrounded alternating 
current power systems, the following methods of grounding will be 
approved:
    (a) A solid connection between the metallic frame; casing, or other 
metal enclosure and the grounded metallic sheath, armor, or conduit 
enclosing the power conductor feeding the electric equipment enclosed;
    (b) A solid connection to metal waterlines having low resistance to 
earth;
    (c) A solid connection to a grounding conductor extending to a low-
resistance ground field; and,
    (d) Any other method of grounding, approved by an authorized 
representative of the Secretary, which insures that there is no 
difference in potential between such metal enclosures and the earth.