[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: 30CFR57.12069]



[Page 379]

 

                       TITLE 30--MINERAL RESOURCES

 

  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR

 

PART 57_SAFETY AND HEALTH STANDARDS_UNDERGROUND METAL AND NONMETAL MINES

--Table of Contents

 

                          Subpart K_Electricity

 

Sec.  57.12069  Lightning protection for telephone wires and ungrounded 

conductors.



    Each ungrounded conductor or telephone wire that leads underground 

and is directly exposed to lightning shall be equipped with suitable 

lightning arrestors of approved type within 100 feet of the point where 

the circuit enters the mine. Lightning arrestors shall be connected to a 

low resistance grounding medium on the surface and shall be separated 

from neutral grounds by a distance of not less than 25 feet.