Changes to the 2017 National Electrical Code PE 2017 Presentation... · The 2017 National Electric...

Changes to the 2017 National Electrical Code

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The 2017 National Electric Code:

“IntroducesmorechangestoArticle690,‘SolarPhotovoltaic(PV)Systems’,thananyrevisioncyclesince1984,whentheNECfirstadoptedArticle690”

BillBrooks

2017 NEC

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Main Changes to Article 690New articles added to NEC:• 691: Large Scale Photovoltaic (PV) Electric Power Production

Facility• Article 706: Energy Storage Systems• Article 710: Stand Alone Systems• Article 712: Direct Current Micro Grids (This will not be covered

today)

Articles removed from the NEC:• 690.35: Ungrounded PV Power Systems

2017 NEC

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Defined the limits of the PV system.

The 2017 version of the NEC redefined the PV System disconnect. It is now system dependent:

• 690.13 Photovoltaic System Disconnecting Means. Means shall be provided to disconnect the PV system from all wiring systems including power systems, energy storage systems, and utilization equipment and its associated premises wiring.

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2017 NEC

Drawingcourtesy:SolarProfessionalMagazine,May/June20165

2017 NEC


Adds new definition for Grounding in Article 690:

Functional Grounded PV System: A PV system that has an electrical reference to ground that is not solidly grounded.

• Acknowledges that most PV systems installed in the last 20 years were functionally grounded PV Systems.

• This uses a definition used and accepted in Europe.

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What the new functional grounding definition means:

• A single overcurrent device shall be permitted to protect the PV modules and conductors of each source circuit. (690.9(C))

• Disconnect switches shall isolate all PV equipment from all conductors that are not solidly grounded. (690.15)

• It is easier to replace grounded inverters with transformerless or non-isolated inverters.

• All PV systems are subject to the same installation requirements under NEC 2017, regardless of inverter topology.

2017 NEC

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690.7 Maximum Voltage.

- The highest voltage between any two circuit conductors or any conductor and ground.

• One and two family dwellings still limited to 600Vdc.• PV Systems DC circuits on other types of buildings shall be permitted to

have a maximum voltage of 1000 volts or less.• Where not located on buildings, listed PV equipment, rated at a maximum

voltage of 1500Vdc or less.

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Maximum Voltage and Current:

For a PV system with a generating capacity of 100kW or greater:• Maximum system voltage calculated by an industry standard method shall be

permitted. (References Sandia publication SAND 2004-3535)• Maximum PV Source and output current can be calculated using industry

standard methods. The calculated maximum current shall be based on the highest 3 hour current average resulting from the simulated local irradiance. The current calculated using this method shall not be less than 70% of the value calculated using the method described in 690.8(A)(1)(1).

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2017 NEC

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690.12RapidShutdown690.12(B)- Controllimits:• Arrayboundaryisloweredto30cm(1ft)inalldirections.All

conductorsoutsidethisboundaryshallbelimitedtonomorethan30Vwithin30secondsofinitiatingRapidShutdown.

2017 NEC

690.12RapidShutdown690.12(B)(2)InsidetheArrayBoundary:1. ThePVarrayshallbelistedorfieldlabeledasarapidshutdownPV

array.2. ConductorslocatedinsidethePVarrayboundaryornotmorethan

one1meter(3ft)fromthepointofpenetrationofthesurfaceofthebuildingshallbelimitedtonotmorethan80voltswithin30secondsofrapidshutdowninitiation.

3. PVArrayswithnoexposedwiringmethods,noexposedconductiveparts,andinstalledmorethan2.5m(8ft)fromexposedgroundedconductivepartsorgroundshallnotberequiredtocomplywith690.12(B)(2)

Thissection(690.(B)(2)doesnotbecomeeffectiveuntil1January2019.

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2017 NEC

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690.12RapidShutdown690.12(C)- Initiationdevice:• Thedevice“off”positionshallindicatethatRapidShutdownhasbeen

initiated• Foroneandtwofamilydwellings,theinitiationdeviceshallbelocated

atareadilyaccessiblelocationoutsidethebuilding.• TheRapidShutdowninitiationdeviceshallconsistofatleastoneofthe

following:o PVsystemdisconnecto ServiceDisconnecto Readilyaccessibleswitch

• Amaximumofsixdevicestoinitiaterapidshutdownofmultiplesystems.

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690.12RapidShutdown(D)- Equipment:EquipmentthatperformstheRapidShutdownfunctions,otherthaninitiationdevicessuchaslisteddisconnectswitches,circuitbreakers,orcontrolswitches,shallbelisted,labeledandidentifiedforprovidingRapidShutdownprotection.

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RapidShutdown690.56IdentificationofPowerSources.• ThetypeofRapidShutdownequipmentshallbeidentified.• BuildingswithmorethanonetypeofRapidShutdownequipment

mustshowareasaroundPVsystemthatareenergizedaftertheRapidShutdownswitchisoperated.

• TheRapidShutdownswitchshallbelabeled.

2017 NEC

690.11Arc-FaultCircuitProtection(DirectCurrent)

• AnexemptiontotheArc-FaultrequirementforPVsystemsthatare notinstalledonbuildingshasbeenaddedto2017.

• LargesystemsonbuildingsarestillrequiredtohaveArc-Faultprotectionequipment.

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2017 NEC

PVSystemLabeling

• MaximumpowerpointvoltageandcurrenthavebeenremovedfromDCswitchlabelrequirements.

• PVsystemoutputcircuitsshallbemarkedtoshowpolaritywhereconnectedtoanenergystoragedevice.

• Rapidshutdownlabelingrequirementshavebeenexpandedtoinclude:- Rapidshutdowntype- Identifyrapidshutdownswitch- Identifywhichsystemshaverapidshutdownforbuildingswithmore

thanonerapidshutdowntype• ReferencesArticle705.10forsystemswithbothutilityandPVsystems

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2017 NEC

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Article691:LargeScalePhotovoltaic(PV)ElectricPowerProductionFacility

Scope:CoverstheinstallationoflargescalePVelectricpowerproductionfacilitieswithageneratingcapacityofnolessthan5,000kW,andnotunderexclusiveutilitycontrol.

InformationalnotesreferencetheNationalElectricalSafetyCodeandindicatethatfacilitiescoveredby691“havespecificdesignandsafetyfeaturesuniquetolargescalePVsystemsoperatedforthesolepurposeofprovidingelectricsupplytoasystemoperator”

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691.4SpecialRequirementsforLargeScalePVElectricSupplyStations

• Accessibletoonlyauthorizedpersonnel• Operatedandmaintainedonlybyqualifiedpersonnel• AccesstoPVsystemtoberestrictedbyfencingorotheradequatemeans• TheconnectionbetweenthePVsystemandthegridshallbethrough

mediumorhighvoltageswitchgear• Electricalloadswithinthefacilityshallonlypowerequipmentforthe

generationofPVpower• LargescalePVelectricsupplystationsshallnotbeinstalledonbuildings.

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691:LargescalePVpowersystems

• Tryingtoenforcestandard690requirementsdidnotmakesense.• Equipmentmaynotbelistedand/orlabeled.Article691allowsfor

approvalby“engineeringreviewvalidatingthattheelectricalequipmentistestedtorelevantstandards”

• Documentationof,andindependentengineeringreportsoftheelectricalportionoftheengineeringdesignshallbestampedbyaprofessionalelectricalengineerandshalldetailconformanceofthedesigntoArticle690oralternativemethodstoArticle690orotherarticlesofthiscode.

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Article705:InterconnectedElectricPowerProductionSources

705.12(B)(2)(d):Aconnectionateitherendbutnotbothendsofacentertappedpanelboardisallowedaslongasthesum125%ofthepowersource(s)outputcircuitcurrentandtheratingoftheovercurrentdeviceprotectingthebusbardoesnotexceed120%ofthecurrentratingofthebusbar.

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705.12(D)(6)WireHarnessandExposedCableArc-FaultProtection

Duetoissuescomplyingwiththissectionformicroinverter,ithasbeenremovedfromthe2017NEC.InadditionTIA14-11wasissuedthatremoves705.12(D)(6)fromthe2014versionofthecode.

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PartIV.MicrogridSystems

MicrogridshavebeenaddedtoArticle705.

Definedin705.2as“Apremiseswiringsystemthathasgeneration,energystorageandload(s),oranycombinationthereof,thatincludestheabilitytodisconnectfromandparallelwiththeprimarysource”.

InformationalNote:Theapplicationofarticle705tomicrogridsystemsislimitedbytheexclusionsin90.2(B)(5)relatedtoelectricutilities(exclusivecontrol).

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Article706EnergyStorageSystems

Scope:Thisarticleappliestoallpermanentlyinstalledenergystoragesystems(ESS)operatingatover50voltsacor60voltsdcthatmaybestandaloneorinteractivewithotherelectricpowerproductionsources.

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Notcoveredintoday’sdiscussion.Theadditionof:

Article710Stand-AloneSystems

Article712DirectCurrentMicrogrids

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OtherChangestotheSection690:• 690.2NewdefinitionsforDC-to-DCconvertercircuits,PVSystemdccircuit,

Generatingcapacity,functionalgroundedPVsystem• 690.4(D)clarifiesthatmultiplePVsystems,notjustmultipleinvertersare

permittedonasinglebuilding• 690.4(E)clarifiesthatPVsystemequipmentanddisconnectingmeansshall

notbeinstalledinbathrooms.• 690.13(F)Typeofdisconnectdefinessimultaneousdisconnectionofall

conductors,prohibitsuseofdevicesmarked“line”and“load”frombeingbackfedandallowstheuseofvarioustypesofDCratedswitches.

• 690.15definesanisolatingdevice,ratingrequirementsforequipmentdisconnectingmeansandrequirementsforequipmentdisconnectingmeans.

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MoreChangestotheSection690:• 690.31(B)(1)DisallowstheuseofwhitewireonthedcsideofaPVsystem

foranythingexceptsolidlygroundedPVsystems.• 690.72Selfregulatedchargecontrollers.• Table690.31(E)forminimumPVwirestrandsforflexiblecordsandcables

(table690.31(E)Correctionfactorsfromthe2014NEChasbeenrelabeledtotable690.31(A))

• 690.47(B)AdditionalAuxiliaryElectrodesforArrayGrounding• 690.59ConnectionstoOtherSourcesreferencesPartsIandIIofArticle

705.• PartVIIIrenamedtoEnergystoragesystemsandreferencesarticle706.• PartIX.Systemsover1000VoltsandPartX.ElectricVehicleCharging,both

removedfromArticle690astheyarecoveredelsewhere.

NYS Uniform Code Amendments and Supplements for Roof

Mounted Solar Electric Arrays

Fire Code and Structural Code Issues in Siting Residential and Commercial Systems

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Safety concerns expressed by the fire fighting community, regarding exposure to high dc voltage roof top, or concealed conductors has fostered many changes in the 2014 NEC.

Access to ground mounted, and access and ventilation of roofs with solar arrays on them are also of concern. This has resulted in restrictions in the area that can be covered by modules.

NY State has updated its building codes with respect to the location of solar modules for roof and ground mounted arrays during the development of this course.

The following is not an all –inclusive summary of these updates

Fire Codes Issues in Siting PV Systems

• The 2015 International Fire Code (IFC), Section 605.11 addresses requirements for solar photovoltaic power systems.– Requires minimum setbacks for roof-mounted PV arrays to allow

firefighters safe access, pathways and areas for smoke ventilation.

• The 2016 New York State Uniform Fire Prevention and Building Code (the “Uniform Code”) has adopted by reference the 2015 edition of the International Fire Code (2015 IFC) with amendments.– Portions of the 2015 IFC have been adopted in the 2015 edition of

the International Residential Code (2015 IRC) with amendments in SECTION R324: SOLAR ENERGY SYSTEMS.

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• The 2015 International Building Code (2015 IBC) Section 101.4.5 on fire prevention requires compliance with the 2015 International Fire Code (2015 IFC) for commercial buildings and other structures permitted under the 2015 IBC.

• The NY State Uniform Code Supplement has amended Section 605.11 of the 2015 IFC by the replacement of sections 605.11.1 through 605.11.1.2.5 in their entirety, and the addition of a new section 605.11.1.2.6.

– TheseNYamendmentschangethe2015IFCsetbackrequirementsforrooftopmountedPVarraysbasedonnewdefinitionsforACCESSROOF,GROUNDACCESSAREA,andROOFACCESSPOINT.

• NY State has amended the 2015 International Residential Code (2015 IRC) in the 2016 Uniform Code Supplement to include certain fire code requirements for residential construction in Section R324.

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2015 International Fire CodeResidential vs. Commercial

• The residential building code as amended for New York State allows the designers of photovoltaic systems several options and alternatives. These illustrations are offered as possible examples. It is not possible to show every possible scenario. It is however up to the judgement of the local code official to determine final compliance with the code.

• Contractors, design professionals, and AHJ’s must consider many ventilation scenarios and consider that:

– 1.Afirecanbreakoutanywhereinabuilding.– 2.Emergencyrespondersdonothavex-rayvision.Alternateventilationmethodsshouldconsiderfiresoccurringinlessthanideallocations.

– 3.ContractorsandAHJmustrememberthatthedirectionandmagnitudeofaprevailingwindcanaffectthelocationoftheventilationopening

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NYSERDA’s Assessment of These Changes

• R324.7.4 Single ridge roofs. Panels, modules, or arrays installed on roofs with a single ridge shall be located in a manner that provides two, 36 inches wide (914 mm) access pathways extending from the roof access point to the ridge. Access pathways on opposing roof slopes shall not be located along the same plane as the truss, rafter, or other such framing system that supports the pathway.

• Exceptions:# 1.Roofswithslopesof2unitsverticalin12unitshorizontal(16.6percent)andless.

# 2.Structureswhereanaccessrooffrontsastreet,driveway,orotherareareadilyaccessibletoemergencyresponders.

# 3.Oneaccesspathwayshallberequiredwhenaroofslopecontainingpanels,modulesorarraysislocatednotmorethan24inches(610mm)verticallyfromanadjoiningroofwhichcontainsanaccessroof.

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2015 IRC Section R324.7.4Access and Pathways: Single Ridge Roofs

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Single ridge roof showing a smaller array without any exceptions

Source:NYSERDASystemshownwithoutanyexceptionswhereverticalventilationtechniqueswillbeemployedresultinasmallerarray.

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Single ridge roof — single pathway with exception #2 single ridge roof indicating ground access

Source:NYSERDA

Exceptionemployed.Groundaccesspointsmustalignwithroofaccesspoints.Notethatthetwoaccesspointsand36”pathwaysallowtwodirectionsofaccessandegressanddonotshareacommontrussorrafter.Thereisalsoadequateunobstructedgroundaccess.Noteincreasedsizeofarraypossible.

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Single ridge roof — single pathway with exception #3 adjoining roof within 24 Inches

Source:NYSERDA

Withanadjoiningroofwithin24inchesofthearrayroof,applyingexception#3youwouldonlyneedasingleaccesspointandpathwayonthemainroof,asthereissecondaryaccessviaanadjoiningroofwithin24inches.Thisstillallowstwodirectionsofegress,anddoesnotshareacommontrussofrafter.

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Single ridge roof –with Alternate Ventilation Location

Source:NYSERDA

Roof Access

sitew/proposedalternateventilation

Ifventilationisrequireditmaybepossibletoproposeanalternateventilationlocationonroofslopeoppositethearrayorthesidewallofanatticspace.AlternatelocationsshouldbecoordinatedandapprovedbytheAHJ.

Roof Access

Roof Access

• R324.7.5 Hip roofs. Panels, modules, and arrays installed on dwellings with hip roofs shall be located in a manner that provides a clear access pathway not less than 36 inches wide (914 mm), extending from the roof access point to the ridge or peak, on each roof slope where panels, modules, or arrays are located.

• Exceptions: # 1.Roofswithslopesof2unitsverticalin12unitshorizontal(16.6percent)andless.

# 2.Structureswhereanaccessrooffrontsastreet,driveway,orotherareareadilyaccessibletoemergencyresponders.

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2015 IRC Section R324.7.5:Access and Pathways: Hip Roofs

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Hip roof showing alternate venting with two roof pathways and ground access - no exception necessary

Source:NYSERDA

Atypicalhiproof,showingalternateventinglocationandclearaccesspathwaynotlessthan36incheswide(914mm)extendingfromtheroofaccesspointtotheridgeorpeak.

• R324.7.6 Roofs with valleys. Panels and modules shall not be located less than 18 inches (457 mm) from a valley.

• Exception: # Roofswithslopesof2unitsverticalin12unitshorizontal(16.6percent)andless.

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2015 IRC Section R324.7.5:Access and Pathways: Hip Roofs

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Valley Roof showing 18” clearance in yellow to the array-no exception necessary

Source:NYSERDA

Thisimageshowsthe18inchclearspacefromthevalleytothearray.Thereisanadditional18clearspaceontheothersideofthevalleyatB.

B

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Hip roof with exception #2 where access roof fronts a street or driveway

Source:NYSERDA

• R324.7.7 Allowance for smoke ventilation operations. Panels and modules shall not be located less than 18 inches (457 mm) from a ridge or peak.

• Exceptions: # 1.Whereanalternativeventilationmethodhasbeenprovidedorwhereverticalventilationmethodswillnotbeemployedbetweentheuppermostportionofthesolarphotovoltaicsystemandtheroofridgeorpeak.

# 2.Detachedgaragesandaccessorystructures.

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2015 IRC Section R324.7.7Allowance for Smoke Ventilation

The following slides provide NY amendments to the 2015 IFC that apply to COMMERCIAL buildings constructed per the 2015 IBC.

Many of the requirements are the same as amended to the 2015 IRC Section 324.7 regarding new requirements for access, pathways and ventilation.

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2015 IFC Section 605.11.1.3Requirements for Other Than Group R-3 Buildings

• 605.11.1.3 Other than Group R-3 buildings. Access to systems for buildings, other than those containing Group R-3 occupancies, shall be provided in accordance with Sections 605.11.1.3.1 through 605.11.1.3.3.

• Exception: Where it is determined by the fire code official that the roof configuration is similar to that of a Group R-3 occupancy, the residential access and ventilation requirements in Sections 605.11.1.2.1 through 605.11.1.2.5 shall be permitted to be used.

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2015 IFC Section 605.11.1.3Requirements for Other Than Group R-3 Buildings

• 605.11.1.3.1 Access. There shall be a minimum 6-foot-wide clear perimeter around the edges of the roof.

– Exception:Whereeitheraxisofthebuildingis250feetorless,theclearperimeteraroundtheedgesoftheroofshallbepermittedtobereducedtoaminimum4footwide.

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Requirements for Other Than Group R-3 Buildings2015 IFC Section 605.11.1.3.1: Access

• 605.11.1.3.2 Pathways. The solar installation shall be designed to provide designated pathways. The pathways shall meet the following requirements:

– 1.Thepathwayshallbeoverareascapableofsupportingfirefightersaccessingtheroof.

– 2.Thecenterlineaxispathwaysshallbeprovidedinbothaxesoftheroof.Centerlineaxispathwaysshallrunwheretheroofstructureiscapableofsupportingfirefightersaccessingtheroof.

– 3.Pathwaysshallbeastraightlinenotlessthan4feetcleartoroofstandpipesorventilationhatches.

– 4.Pathwaysshallprovidenotlessthan4feetcleararoundroofaccesshatchwithnotlessthanonesingularpathwaynotlessthan4feetcleartoaparapetorroofedge.

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Requirements for Other Than Group R-3 Buildings2015 IFC Section 605.11.1.3.2: Pathways

• 605.11.1.3.3 Smoke ventilation. The solar installation shall be designed to meet the following requirements:

– 1.Arraysshallbenotgreaterthan150feetby150feetindistanceineitheraxisinordertocreateopportunitiesforfiredepartmentsmokeventilationoperations.

– 2.Smokeventilationoptionsbetweenarraysectionsshallbeoneofthefollowing:

– 2.1.Apathway8feetorgreaterinwidth.– 2.2.A4-footorgreaterinwidthpathwayandborderingroofskylightsorgravity-operateddropoutsmokeandheatventsonnotlessthanoneside.

– 2.3.A4-footorgreaterinwidthpathwayandborderingallsidesofnongravity-operateddropoutsmokeandheatvents.

– 2.4.A4-footorgreaterinwidthpathwayandbordering4-footby8-footventingcutoutsevery20feetonalternatingsidesofthepathway.

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Requirements for Other Than Group R-3 Buildings2015 IFC Section 605.11.1.3.3: Smoke Ventilation

Access, Pathways and Ventilation: Examples

Access pathways are provided around the perimeter and throughout building-mounted PV arrays to provide for firefighter access and ventilation.

Access, Pathways and VentilationLarge Commercial Example

LargeCommercial(Axis>250’)8’Walkways

CALFIRE-OSFMAccess pathways51

Building Requirements: Large Commercial ExampleCodeCompliantforLargeCommercial

Building Requirements: Large Commercial Example

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CodeCompliantforLargeCommercial

Fire Code Issues in Siting Systems

Access and Ventilation Requirements are a function of Building Size

Access pathways

CAL FIRE-OSFM

Building Requirements: Small Commercial Example

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CodeCompliantforSmallCommercial



Access pathways

Access pathways CAL FIRE-OSFM

Building Requirements: Small Commercial Example

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CodeCompliantforSmallCommercial



Photos courtesy of DOE/NREL

Ground Mounted Systems

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• R324.6Ground-mountedphotovoltaicsystems.Ground-mountedphotovoltaicsystemsshallbedesignedandinstalledinaccordancewithSectionR301(DesignCriteria).⁻ R324.6.1Fireseparationdistances.Ground-mountedphotovoltaic

systemsshallbesubjecttothefireseparationdistance requirementsdeterminedbythelocaljurisdiction.

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Question and Answer Assessment

NEC2017Q1)WhataretheboundarylimitationsforRapidShutdown?A1) Arrayboundaryis30cm(1ft)inalldirections.Allconductorsoutsidethisboundaryshallbelimitedtonomorethan30Vwithin30secondsofinitiatingRapidShutdown.Q2)Whatisthehighestvoltageallowedonbuildingsotherthanoneortwofamilydwellings?A2)PVSystemsDCcircuitsonothertypesofbuildingsshallbepermittedtohaveamaximumvoltageof1000voltsorless.Q3)Whatchangeshavebeenmadetofacilitatethereplacementofisolatedinverterswithnonisolatedinverters?A3)Disconnectswitchwiringandovercurrentprotectionhasbeenmademostlyuniformirrespectiveofwhethertheinverterisisolatedornonisolated.NYSUniformCodeAmendmentsandSupplementsforRoofMountedArraysQ4)WhatisoneofthepurposesofTheUniformCodeAmendmentsandSupplementforRoofMountedArrays?A4)Toallowalternativepathsforaccessandventilationofroofsinthecaseofafire.Q5)WhoultimatelyhasdecisionmakingauthorityforaccessandventilationplansA5)TheAuthorityHavingJurisdiction(AHJ).ConferwiththeAHJontheseplans.

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