For PV systems, where are circuits terminating on buildings not considered controlled conductors?

In photovoltaic (PV) systems, circuits that terminate on the exterior of buildings are not considered controlled conductors due to safety and accessibility concerns. The exterior of structures is typically more susceptible to environmental factors and requires careful consideration in terms of installation and maintenance.

The distinction lies primarily in how accessible these areas are for personnel and the potential hazards that may arise from exposure to weather, wildlife, and other external elements. Circuits on the exterior may also pose risks such as electrical shock to individuals who might be in proximity to the equipment, especially during adverse weather conditions.

In contrast, interior installation locations typically allow for better control over environmental conditions and accessibility for maintenance, leading to a greater level of safety. Rooftops, while they might be part of building structures, are often treated similarly to exterior areas due to height and exposure, and underground installations follow a separate set of rules regarding conductor control.

Overall, the classification of exterior circuits as uncontrolled takes into account both safety practices and compliance with NEC requirements to ensure safe installation and operation of PV systems.