Code Change Summary: Revised text in 705.12(D)(1) makes it clear that there can only be one fusible disconnecting means or circuit breaker at the point where a PV system interconnects to the primary electrical source.

Article 705 is all about other power production sources (besides the normal source of power to a premises) operating in parallel with the primary source of electricity.

In a utility interactive PV system for example, the actual PV system is covered in Article 690 and how the PV system interconnects to the utility power for the premises is covered in Article 705.

The previous use of the word “each” was confusing and technically allowed more than one PV interconnection point. If two inverters were present, the old code language allowed two backfed circuit breakers at the point where the inverter output circuit connected to the premises panelboard.

Now, the 2014 NEC^® makes it clear that even if several inverters are installed, only one backfed point of interconnection to the premises wiring is allowed (see image).

Below is a preview of the NEC^®.  See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).