Approved GroundsA
This chapter describes the approved grounds appropriate for the
Definition of Approved Ground
An approved ground is the closest acceptable medium for grounding the building entrance protector, entrance cable shield, or
If more than one type of approved ground is available on the premises, the grounds must be bonded together as required in Section
Acceptable Mediums for Protective
Ground
The following protective ground types are acceptable:
Grounded Building Steel. — The metal frame of the b uilding where it is effectively grounded by one of the following grounds: acceptable metallic water pipe, concrete encased ground, or a ground ring.
Acceptable Water Pipe. — A metal underground wa ter pipe, at least 1/2 inch (1.3 cm) in diameter, in direct contact with the earth for at least 10 feet (3 meters). The pipe must be electrically continuous (or made electrically continuous by bonding around insulated joints, plastic pipe, or plastic water meters), to the point where the protector ground wire is connected. A metallic underground water pipe must be supplemented by the metal frame of the building, a concrete
Issue 1 September 1995
