Interpretation #8022
Published November 09, 2017
Original Request
- Code Version
- 2014
- Code
- NEC
- Code Description
- Chapter
- 6
- Section
- 690.31(E)
- Topic
- Alternating current inverter output circuits running through a building.
Question
Is an AC inverter output circuit running through a building required to comply with the requirements of NEC 690.31(E)?
Answer Published 11/09/2017 at 7:49 AM
The question refers to the 5th edition Florida Code, which uses the 2011 NEC as the referenced standard. While this issue is "fixed" in the 2014 NEC, which will be a part of the 6th edition Florida Code, the 2011 NEC indicates the answer is yes. Please see the attached commentary.
Commentary
The issue addressed by this section is the use of DC circuits and the inherent safety issues working with DC. Technology of PV systems has advanced dramatically and the widespread use of microinverters in place today means different systems and installations than previously. While the NEC has evolved rapidly, as has the technology of solar PV systems, the Code is always catching up. The 2014 NEC addresses the issues by adding the words "Direct-Current" into 690.31(G) and the difference is is now clear. Additionally, the 2014 has solved many of the issues from earlier editions and updated much information for what is currently in the marketplace, at the time of the writing of the document.