NCCER Residential Wiring Practice Exam

Service entrance cables are typically made from aluminum due to its favorable properties for electrical applications. Aluminum is lightweight, cost-effective, and has good conductivity, allowing it to carry sufficient electrical current for residential service use. Additionally, aluminum conductors are often used because they can significantly reduce the overall weight of the cables, which is beneficial for installation purposes.

While copper is also a conductor frequently used in electrical systems, it is generally employed in smaller wiring applications rather than for service entrances due to its higher cost and weight. Steel is not used for service entrance cables; it is more often utilized in conduits or as a structural element in some electrical equipment because it does not have the same conductivity properties. Plastic may be used as insulation or protective sheathing around conductors, but it does not serve as the primary material for the conductors themselves. Thus, aluminum stands out as the most common choice for service entrance cables in residential wiring applications.