What must all service-entrance conductors be when entering or on the exterior of buildings?

Service-entrance conductors play a critical role in the safety and functionality of electrical systems within buildings. When these conductors exit the utility's distribution system and enter a building, they must be insulated for several key reasons.

Insulation provides a protective barrier that prevents accidental contact with conductive materials, reducing the risk of electrical shock to individuals and ensuring safety. Moreover, insulation helps to protect the conductors from environmental factors such as moisture, which can lead to corrosion or electrical failures over time. Proper insulation also assists in maintaining the integrity of the electrical system by minimizing the risk of short circuits.

Conductors that are not properly insulated could pose a significant hazard, especially if they are exposed to people, animals, or other conductive elements. This requirement emphasizes ensuring safe and secure entry points for electrical systems into buildings, conforming to building codes and regulations that prioritize safety standards in electrical installations.

In contrast, non-insulated conductors would expose individuals to the risk of electric shock and allow for increased vulnerability to damage, while buried conductors are not suitable for entry points and exposed conductors contradict safety norms by lacking protective measures. Therefore, insulation is essential in providing a safe and reliable electrical service entrance.