Which of the following statements about the installation of grounding electrodes is not true?

A. A water pipe grounding electrode must be supplemented by at least one other grounding
electrode.
B. A concrete-encased grounding electrode must be at least 21?2 ft (750 mm) below the
earth’s surface.
C. A ground ring grounding electrode must encircle the building at a depth of 21?2 ft (750
mm) or more.
D. A pipe-type grounding electrode must be driven 8 ft (2.5 m) vertically where
practicable.


B. A concrete-encased grounding electrode must be at least 21?2 ft (750 mm) below the
earth’s surface.

Trades & Technology

You might also like to view...

At higher altitudes, lower temperatures are required to boil water

Indicate whether the statement is true or false

Trades & Technology

The component location diagram:

A) Shows the operating sequence of the system components. B) Gives the network address of each piece of equipment in the multicomponent cooling network. C) Shows how the unit interfaces with other units in a multicomponent cooling network. D) Is used to locate actual parts and connections within the unit itself.

Trades & Technology

Mudsills used to support shores must be sound and _____

a. rigid b. smooth c. dense d. flexible

Trades & Technology

Which of the following is an invalid BCD code?

A) 0011 B) 1101 C) 1001 D) 0101

Trades & Technology