ICC Residential Electrical Inspectors Practice Exam

Which wiring method cannot be used as a raceway for service conductors emerging from an underground installation?

1. Schedule 40 PVC conduit

2. Electrical metallic tubing (EMT)

3. Schedule 80 PVC conduit

4. Steel conduit

The correct answer is: Schedule 40 PVC conduit

The correct choice indicates that Schedule 40 PVC conduit cannot be used as a raceway for service conductors emerging from an underground installation. This is because Schedule 40 PVC conduit is rated for underground use primarily for non-service conductors. Conduits used as raceways for service conductors must be robust and capable of withstanding potential physical damage as well as environmental factors. Schedule 80 PVC, on the other hand, is thicker and provides more durability, making it suitable for such applications. Steel conduit and electrical metallic tubing (EMT) also provide a greater level of protection due to their metal construction, which enhances their ability to safeguard conductors in adverse situations. In summary, the limitations associated with Schedule 40 PVC conduit in this context revolve around its construction and intended use, which do not align with the requirements needed for handling service conductors that emerge from underground installations.