entering the building or terminating on the outside of the building shall comply with 800.93(A) or (B).

(A) Entering Buildings. In installations where the com- munications cable enters a building, the metallic sheath members of the cable shall be either grounded as specified in 800.100 or interrupted by an insulating joint or equivalent device. The grounding or interruption shall be as close as practicable to the point of entrance.

(B) Terminating on the Outside of Buildings. In instal- lations where the communications cable is terminated on the outside of the building, the metallic sheath members of the cable shall be either grounded as specified in 800.100 or interrupted by an insulating joint or equivalent device. The grounding or interruption shall be as close as practicable to the point of termination of the cable.

FPN: See 800.2 for a definition of Point of Entrance.

IV. Grounding Methods

800.100 Cable and Primary Protector Grounding. The primary protector and the metallic member(s) of the cable sheath shall be grounded as specified in

800.100(A) through (D).

(A) Grounding Conductor.

(1) Insulation. The grounding conductor shall be insulated and shall be listed.

(2) Material. The grounding conductor shall be copper or other corrosion-resistant conductive material, stranded or solid.

(3) Size. The grounding conductor shall not be smaller than 14 AWG.

(4) Length. The primary protector grounding conductor shall be as short as practicable. In one- and two-family dwellings, the primary protector grounding conductor

shall be as short as practicable, not to exceed 6.0 m (20 ft) in length.
FPN: Similar grounding conductor length limitations applied at apartment buildings and commercial buildings help to reduce voltages that may be developed between the building's power and communications systems during lightning events.

Exception: In one- and two-family dwellings where it is not practicable to achieve an overall maximum primary protector grounding conductor length of 6.0 m (20 ft), a separate communications ground rod meeting the minimum dimensional criteria of800.100(B)(2)(2) shall be driven, the primary protector shall be connected to the communications ground rod in accordance with

800.100(C), and the communications ground rod shall be connected to the power grounding electrode system in accordance with 800.100(D).

(5) Run in Straight Line. The grounding conductor shall be run to the grounding electrode in as straight a line as practicable.

(6) Physical Protection. The grounding conductor shall be protected where exposed to physical damage. Where the grounding conductor is run in a metal raceway, both ends of the raceway shall be bonded to the grounding conductor or the same terminal or electrode to which the grounding conductor is connected.

(B) Electrode. The grounding conductor shall be con- nected in accordance with 800.100(B)(1), (B)(2), or (B)(3).

(1) In Buildings or Structures with an Intersystem Bonding Termination. If the building or structure served has an intersystem bonding termination, the grounding conductor shall be connected to the intersystem bonding termination.

(2) In Buildings or Structures with Grounding Means.

If the building or structure served has no intersystem

bonding termination, the grounding conductor shall be

connected to the nearest accessible location on the

following:

(1) The building