ICC Residential Electrical Inspectors Practice Exam

What is a concrete encased electrode made up of according to the National Electrical Code?

1. Reinforcing bars encased in concrete

2. Bare copper wire placed in concrete

3. Metal conduit embedded in concrete

4. Poured concrete footings with grounding cables

The correct answer is: Reinforcing bars encased in concrete

A concrete encased electrode is defined by the National Electrical Code as being composed of reinforcing bars that are encased in concrete. This component plays a crucial role in grounding systems, as it effectively provides a low-resistance path to ground, ensuring electrical safety and system stability. The use of reinforcing bars, often referred to as rebar, allows for structural reinforcement in concrete while simultaneously serving an important electrical grounding function. When properly installed, these bars can significantly enhance the overall grounding system by taking advantage of the conductive properties of the concrete and the metal rebar itself. Other options, while they may involve materials that could potentially serve grounding purposes, do not fit the specific definition outlined in the National Electrical Code. For instance, bare copper wire placed in concrete or metal conduit embedded in concrete do not meet the exact criteria, nor do poured concrete footings with grounding cables, which are not recognized as concrete encased electrodes under the code. Understanding the precise definition helps ensure compliance with safety standards in electrical installations.