Under what condition is overcurrent protection for PV system dc circuit conductors not required?

Overcurrent protection for PV system dc circuit conductors is not required under the condition that currents do not exceed the maximum ratings. This is based on the understanding that if the current flowing through the conductors remains within a safe limit—specifically below the rated capacity of the conductors and protection devices—the risk of damage due to overcurrent is minimized.

In solar photovoltaic systems, the National Electrical Code recognizes that if the system operates within those set limits, the conductors can safely carry the current without the need for additional protective devices such as fuses or circuit breakers. This approach is designed to ensure both safety and efficiency in energy production while reducing unnecessary complexity in the system design.

The other options do not align with the NEC requirements for overcurrent protection. While minimum conductor size and grounding are important, they do not inherently negate the requirement for overcurrent protection if the system can still experience conditions that exceed the safe current-carrying capacity. Similarly, limiting inverter capacity is also relevant but does not directly address the current levels within the conductors themselves. Therefore, ensuring that currents do not exceed maximum ratings is the fundamental criterion for not requiring overcurrent protection in PV system dc circuits.