When are PV system conductors permitted to occupy the same raceway as non-PV conductors?

The permitted conditions for photovoltaic (PV) system conductors to occupy the same raceway as non-PV conductors are addressed in the NEC to ensure safety and circuit integrity. The correct situation is when the conductors are separated by a barrier or partition. This requirement is in place to prevent the potential for electromagnetic interference, which can affect the performance of both PV and non-PV systems. By physically separating the conductors within the raceway, the risk of negative interactions is minimized, ensuring reliable operation of both types of circuits.

Other options do present relevant considerations, but they do not specifically meet the NEC criteria for raceway sharing. For example, although having conductors rated for the same voltage suggests they might be compatible, it does not address the necessity of separation to mitigate interference. Similarly, while sharing the same rating can imply similar load handling capabilities, it doesn't inherently ensure the safety and performance standards required for mixed conductor use in a raceway. The use of multiconductor cable could facilitate various configurations, but it still does not provide the necessary separation to comply with NEC regulations regarding separate systems.