4 Va. Admin. Code § 25-40-2480
A lightning arrester shall be provided where telephone circuits enter a mine; mine telephone extensions in surface buildings shall be provided with a lightning arrester for each circuit entering the building.
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Derived from VR480-05-1.2 § 12.47, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.