What type of overcurrent protection is required for PV output circuits?

The requirement for overcurrent protection on photovoltaic (PV) output circuits is specifically designed to ensure the safe operation of solar power systems. The correct choice states that a disconnecting means and non-load break rated devices are necessary for these circuits.

In the context of NEC Article 690, PV systems must include a means to isolate the solar output circuits safely from the rest of the electrical system. This is vital for maintenance and emergency situations, ensuring that technicians can work on the system without the risk of electrical shock or equipment damage from inadvertent circuit energization. The use of a disconnecting means provides a clear visual indicator that the circuit is de-energized and safe to work on.

Non-load break rated devices are employed to handle fault conditions and provide overcurrent protection without requiring the device to interrupt load current. These devices can safely interrupt current when a fault occurs, but they are not designed for general switching duties while under load, which could result in dangerous conditions or equipment failure.

Other options do not meet the specific requirements laid out in the NEC for PV systems. For example, circuit breakers with load break ratings would imply capability for regular operation under load, which does not align with the intended use here. Fuses, while adequate for certain applications, do