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SUMMARY OF 2011 NEC CHANGESBill BrooksBrooks EngineeringWard BowerSandia National LaboratoriesSolar ABCs Stakeholder MeetingOctober 15, 2010Los Angeles, CA
Acknowledgements2011 NEC Changes for PVThe authors wish to acknowledge the participation,collaboration and expertise of nearly 150 dedicatedengineers, installers, designers, technicians and PVindustry associates that participated in the “IndustryForum” for Article 690-Solar Photovoltaic Systemsand Article 705-Interconnected Electrical PowerProduction Sources, of the 2011 Edition of theNational Electrical Code.John Wiles served assecretary and submitter of forum proposals. TheSolar ABCs provided the important portal fordissemination of related activities.
Statistics on Articles 690 & 705Proposals for the 2011 NEC 79 Proposals for Article 690– 43 from the PV Industry Forum– 36 from public Article 690 Proposal types–15 Proposals for New Language– 53 Proposals for Revision– 6 Proposals to Move 39 Proposals for Article 690Were Accepted for the ROC.(44 Comments)– 53% of Industry Forum– 44% of Public Proposals 18 Proposals for Article 705– 10 from the PV Industry Forum– 8 from public
NEC PV Links“Industry Forum”Public InputNFPA CoordinationInternational StandardsIEC
Article 690 Changes for 2011 690.2 - Definition for PV Subarrayand Monopole to clarify other partsof Article 690690.4(B-G) - Identification/groupingof conductors of different systems690.4(E) – Installation of conductorsetc by qualified persons!690.4(G) – Requirements forsystem wiring and separations forbipolar.690.7(E) – grounding of bi-polar PVarrays GFD can interrupt ground
Article 690 Changes for 2011 690.8(B) – Good clarification onampacity ratings for conductors andovercurrent devices690.9(B) – Removed need forovercurrent devices between aninverter and transformer690.11 – Language for requirementsfor arc-fault detectors in PV arraycircuits690.13 – Major clarifications fordisconnects for current carryingconductors690.16(A-B) – Servicing fuse anddisconnects*Red indicates major impact change
Article 690 Changes for 2011 690.31(B) – PV wire and conduit fill690.31(E) – Major change for DCsource circuits in metal conduit inbuildings690.43 – Requirements for PVequipment grounding/bonding690.47(B) – Single groundingelectrode with multiple inverters andalternate clamps for circuit breakers690.47(C) – Systems with ac and dcgrounding requirements690.62 – Ampacity of neutralconductor for 3φ Y systems690.63 – Unbalancedinterconnections/POC moved to 705690.72(C) Requirements for BuckBoost converters*Red indicates major impact change
Article 705 Changes for 2011 705.4 System install by qualifiedpersons705.12(A) – Supply side sum ofratings shall not exceed the service705.12(D) – Exception to allow125% for calculation of bus current705.60 – Rating of OvercurrentDevices705.65 – Overcurrent protectionfixes on wholesale transfer of 690language to 705. Deleted PVspecific language and replaced PVsource circuit with inverter outputcircuit.
2011 NEC Activities appear onthe Solar ABCs Website The full ROP and ROC the full draftof the 2011 NEC can bedownloaded from the NFPA Codes.asp?DocNum 70 The activities are also available onthe Solar ABCs web site at
The 2011 NEC Schedule A public comment period closed10/23/2009The CMP4 reviewed and ballotedthe public comment 12/9-12/2009.Formal Paper Ballots submitted1/12/2010Correlating Committee reviewedchanges 2/22-26/10Standards Council Issuancecompleted in August 20102011 NEC published in Sep 2010
The 2011 NEC Schedule A public comment period closed 10/23/2009 The CMP4 reviewed and balloted the public comment 12/9-12/2009. Formal Paper Ballots submitted 1/12/2010 Correlating Committee reviewed changes 2/22-26/10 Standards Council Issuance completed in Augu
