ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS 690.1

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A person designated as a qualified person shall possessthe skills and knowledge related to the constructionand operation of the electrical equipment andinstallation and shall have received documented safetytraining on the hazards involved. Documentation oftheir qualifications shall be on file with the office ofthe establishment in charge of the completedinstallation.

(3) Effective safeguards acceptable to the authority havingjurisdiction are established and maintained.

685.3 Application of Other Articles. The articles/sectionsin Table 685.3 apply to particular cases of installation ofconductors and equipment, where there are orderlyshutdown requirements that are in addition to those of thisarticle or are modifications of them.

ARTICLE 690

Solar Photovoltaic Systems

I. General

690.1 Scope. The provisions of this article apply to solar.photovoltaic electrical energy systems, including the arraycircuit(s), inverter(s), and controller(s) for such systems. [SeeFigure 690.1(A) and Figure 690.1 (B).] Solar photovoltaicsystems covered by this article may be interactive with otherelectrical power production sources or stand-alone, with orwithout electrical energy storage such as batteries. Thesesystems may have ac or dc output for utilization.

Photovoltaic source circuits

Table 685.3 Application of Other Articles

II. Orderly Shutdown

685.10 Location of Overcurrent Devices in or onPremises. Location of overcurrent devices that are criticalto integrated electrical systems shall be permitted to beaccessible, with mounting heights permitted to ensuresecurity fl:om operation by unqualified personnel.

685.12 Direct-Current System Grounding. Two-wire dccircuits shall be permitted to be ungrounded.

685.14 Ungrounded Control Circuits. Where operationalcontinuity is required, control circuits of 150 volts or lessfrom separately derived systems shall be permitted to beungrounded.

Photovoltalcoutput circuit

~ne[

Module

Array or photovoltaicpower source

r.::-=-:::-ld'-"" Solar cells

Dedicated branch circuitr---r----:r---~""I::""-+ of the electric production

and distribution network

Inverter output

........ --'~ ac module {inCludes. inverter}

Array (of ao modules)

Notes:1. These diagrams are intended to be a means of identification for

photovoltaio system components, circuits, and connectfons,2. O.lsconnecling means required by Article GOO, Part III. are not shown,3. System grounding and equipment grounding are not shown.

See Article 690. Part V.

ac module system

Figure 690.1(A) . Identification of Solar PhotovoltaicSystem Components.

Section225, Part II

250.21

240.4240.12

. 240.13(1)

230.95, Exception No.1

430.113,ExceptionNos.1and 2

645.10, Exception645.11(1)

705.12(A)

427.22430.44

430.74, Exception Nos. 1 and 2430.102(A), Exception No.2

More than one building or otherstructure

Ground-fault protection ofequipment

Protection of conductorsElectrical system coordinationGround-fault protection of

equipmentGrounding ac systems of 50

volts to 1000 voltsEquipment protectionOrderly shutdownDisconnectionDisconnecting means in sight

from controllerEnergy from more than one

sourceDisconnecting meansUninterruptible power supplies

(UPS)Point of connection

Conductor/Equipment

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o2007 California Electrical Code

70-545

690.2 ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS

Figure 690.1(8) Identification of Solar Photovoltaic SystemComponents in Common System Configurations.

Charge Controller. Equipment that controls dc voltage ordc current, or both, used to charge a battery.

Diversion Charge Controller. Equipment that regulatesthe charging process of a battery by diverting power fromenergy storage to direct-current or alternating-current loadsor to an interconnected utility service.

Electrical Production and Distribution Network. Apower production, distribution, and utilization system, suchas a utility system and connected loads, that is external toand not controlled by the photovoltaic power system.

Hybrid System. A system comprised of multiple powersources. These power sources may include photovoltaic,wind, micro-hydro generators, engine-driven generators,and others, but do not include electrical production anddistribution network systems. Energy storage systems, suchas batteries, do not constitute a power source for thepurpose of this definition.

Interactive System. A solar photovoltaic system thatoperates in parallel with and may deliver power to anelectrical production and distribution network. For thepurpose of this definition, an energy storage subsystem of asolar photovoltaic system, such as a battery, is not anotherelectrical production source.

Inverter. Equipment that is used to change voltage level orwaveform, or both, of electrical energy. Commonly, aninverter [also known as a power conditioning unit (PCU) orpower conversion system (PCS)] is a device that changesdc input to an ac output. Inverters may also function asbattery chargers that use alternating current from anothersource and convert it into direct current for chargingbatteries.

Inverter Input Circuit. Conductors between the inverterand the battery in stand-alone systems or the conductorsbetween the inverter and the photovoltaic output circuitsfor electrical production and distribution network.

Inverter Output Circuit. Conductors between the inverterand an ac panelboard for stand-alone systems or theconductors between the inverter and the service equipmentor another electric power production source, such as autility, for electrical production and distribution network.

Module. A complete, environmentally protected unitconsisting of solar cells, optics, and other components,exclusive of tracker, designed to generate dc power whenexposed to sunlight.

Panel. A collection of modules mechanically fastened together,wired, and designed to provide a field-installable unit.

Photovoltaic Output Circuit. Circuit conductors betweenthe photovoltaic source circuit(s) and the inverter or dcutilization equipment.

Photovoltaic Power Source. An array or aggregate ofarrays that generates dc power at system voltage andcurrent.

Inverler

J,------,;O' Malnsupply equipmentforde loads

'I<...... Energy storage

dc foads Inverter

---t.----~)"" Charge controller

Photovallalc output Inverter Input clrcu1tcircuit Inverter output

MaIn supplyI-L---equlpmsnttor

acloads

Stand·alone system

Hybrid system

..

Photovollale source circuits Inverter Input clrcult>' », / Inverter output. I ~r~Electrle productionand dlstrlbu1lon

Photovoltalc output clrcult network connecUonInverter

Interactlve system I

690.2 Definitions.

Alternating-Current (ac) Module (Alternating-CurrentPhotovoltaic Module). A complete, environmentallyprotected unit consisting of solar cells, optics, inverter, andother components, exclusive of tracker, designed togenerate ac power when exposed to sunlight.

Array. A mechanically integrated assembly of modules orpanels with a support structure and foundation, tracker, andother components, as required, to fonn a direct-currentpower-producing unit.

Bipolar Photovoltaic Array. A photovoltaic array that hastwo outputs, each having opposite polarity to a commonreference point or center tap.

Blocking Diode. A diode used to block reverse flow ofcurrent into a photovoltaic source circuit.

Building Integrated Photovoltaics. Photovoltaic cells,devices, modules, or modular materials that are integratedinto the outer surface or structure of a building and serve asthe outer protective surface of that building.

N·oles:1. These diagrams are Intendsd to be a means of identification for

photovoltelc systemocmponents, circuits, and connections.2. DIsconnecting means and overcurrent protection required by

Article £90 are not shovm.3. System grounding and equipment grounding are not shown.

See Artlc'le £90, Part V.4. Custom des'lgns occur In each configuration, and some components

are opUonal.

Wind, engine-generator,mlcro.hyoro.efectrlc, and Energy storage, charge controller,other power sources and system control

""....---,&"'" Inverter Input circuit

~ ) ~ ,verteroutput

Pholovoltalc L..-_---I

output·clrcu1t

70-546 2007 California Electrical Code

ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS 690.7

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Photovoltaic Source Circuit. Circuits between modulesand from modules to the common connection point(s) ofthe dc system.

Photovoltaic System Voltage. The. direct current (dc)voltage of any photovoltaic source or photovoltaic outputcircuit. For multiwire installations, the photovoltaic systemvoltage is the highest voltage between any two dcconductors.

Solar Cell. The basic photovoltaic device that generateselectricity when exposed to light.

Solar Photovoltaic System. The· total components andsubsystems that, in combination, convert solar energy intoelectrical energy suitable for connection to a utilizationload.

Stand-Alone System. A solar photovoltaic system thatsupplies power independently of an electrical productionand distribution network.

690.3 Other Articles. Wherever the requirements of otherarticles of this Code and Article 690 differ, therequirements of Article 690 shall apply and, ifthe system isoperated in parallel with a primary source(s) of electricity,the requirements in 705.14, 705.16, 705.32, and 705.43shall apply.

Exception: Solar photovoltaic systems, equipment, orwiring installed in a hazardous (classified) location shallalso comply with 500.1,505.1, and 510.1.

690.4 Installation.

(A) Solar Photovoltaic System. A solar photovoltaicsystem shall be pennitted to supply a building or otherstructure in addition to any service(s) of another electricitysupply system(s).

(B) Conductors of Different Systems. Photovoltaic sourcecircuits and photovoltaic output circuits shall not becontained -in the same raceway, cable tray, cable, outletbox, junction box, or similar fitting as feeders or branchcircuits of other systems, unless the conductors of thedifferent systems are separated by a partition or areconnected together.

(C) Module Connection Arrangement. The connectionsto a module or panel shall be arranged so that removal of amodule or panel from a photovoltaic source circuit does notintenupt a grounded conductor to another photovoltaicsource circuit. Sets of modules interconnected as systemsrated at 50 volts or less, with or without blocking diodes,and having a single overcurrent device shall be consideredas a single-source circuit. Supplementary overcurrentdevices used for the exclusive protection of thephotovoltaic modules are not considered as overcurrentdevices for the purpose of this section.

2007 California Electrical Code

(D) Equipment. Inverters or motor generators shall beidentified for use in solar photovoltaic systems.

690.5 Ground-Fault Protection. Roof-mounted dcphotovoltaic arrays located on dwellings shall be providedwith dc ground-fault protection to reduce fire hazards.

(A) Ground-Fault Detection and Interruption. Theground-fault protection device or system shall be capableof detecting a ground fault, interrupting the flow of faultcurrent, and providing an indication of the fault.

(B) Disconnection of Conductors. The' ungroundedconductors of the faulted source circuit shall beautomatically disconnected. If the grounded conductors ofthe faulted source circuit are disconnected to comply withthe requirements of 690.5(A), all conductors of the faultedsource circuit shall be opened automatically andsimultaneously. Opening the grounded conductor of thearray or opening the faulted sections of the array shall bepennitted to interrupt the ground-fault current path.

(C) Labels and Markings. Labels and markings shall beapplied near the ground-fault indicator at a visible location,stating that, if a ground fault is indicated, the normallygrounded conductors may be energized and ungrounded.

/690.6 Alternating-Current (ac) Modules.

(A) Photovoltaic Source Circuits. The requirements ofArticle 690 pertaining to photovoltaic source circuits shallnot apply to ac modules. The photovoltaic source circuit,conductors, and inverters shall be considered· as internalwiring of an ac module.

(B) Inverter Output Circuit. The output of an ac moduleshall be considered an inverter output circuit.

(C) Disconnecting MEmns. A single disconnecting means,in accordance with 690.15 and 690.17, shall be pennittedfor the combined ac output of one or more ac modules.Additionally, each ac module in a multiple ac-modulesystem shall be provided with a connector, bolted, ortenninal-type disconnecting means.

(D) Ground-Fault Detection. Alternating-current-modulesystems shall be permitted to use a single detection deviceto detect only ac ground faults and to disable the array byremoving ac power to the ac module(s).

(E) Overcurrent Protection. The output circuits of acmodules shall be pennitted to have overClUTent protectionand conductor sizing in accordance with 240.5(B)(2).

70-547

690.8 ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS

ITable 690.7 Voltage Correction Factors for Crystallineand Multicrystalline Silicon Modules

II. Circuit Requirements

690.7 Maximum Voltage.(A) Maximum Photovoltaic System Voltage. In a dcphotovoltaic source circuit or output circuit, the maximumphotovoltaic system voltage for that circuit shall becalculated as the sum of the rated open-circuit voltage ofthe series-connected photovoltaic modules corrected for thelowest expected ambient temperature. For crystalline andmulticrystalline silicon modules, the rated open-circuitvoltage shall be multiplied by the correction factorprovided in Table 690.7. This voltage shall be used todetermine the voltage rating of cables, disconnects,overcurrent devices, and other· equipment. Where thelowest expected ambient temperature is below -40°C (­40°F), or where other than crystalline or multicrystallinesilicon photovoltaic modules are used, the system voltageadjustment shall be made in accordance with themanufacturer's instructions.

(B) Direct-Current Utilization Circuits. The voltage ofdc utilization circuits shall conform with 210.6.

(C) Photovoltaic Source and Output Circuits. In one­and two-family dwellings, photovoltaic source circuits andphotovoltaic output circuits that do not includelampholders, fixtures, or receptacles shall be permitted tohave a maximum photovoltaic system voltage up to 600volts. Other installations with a maximum photovoltaicsystem voltage over 600 volts shall comply with Article690, Part I.(D) Circuits Over 150 Volts to Ground. In one~ and two­family dwellings, live parts in photovoltaic source circuitsand photovoltaic output circuits over 150 volts to groundshall not be accessible to other than qualified persons whileenergized.

FPN: See 110.27 for guarding of live parts, and 210.6 forvoltage to ground and between conductors.

(E) Bipolar Source and Output Circuits. For 2-wirecircuits connected to bipolar systems, the maximum system

AmbientTemperature (OC)

25 to 109 to 0

-1 to -10-11 to -20-21 to -40

Correction Factorsfor Ambient

TemperaturesBelow 25°C (77°F)(Multiply the ratedopen-circuit voltageby the appropriatecorrection factor

shown below.)1.061.101.131.171.25

AmbientTemperature (OF)

77 to 5049 to 3231 to 1413 to-4

-5 to -40

voltage shall be the highest voltage between the conductorsof the 2-wire circuit ifall of the following conditions apply:

(1) One conductor of each circuit is solidly grounded.

(2) Each circuit is connected to a separate subarray.

(3) The equipment is clearly marked with a label asfollows:

WARNING

BIPOLAR PHOTOVOLTAIC ARRAY.

DISCONNECTION OF NEUTRAL OR

GROUNDED CONDUCTORS MAY RESULT IN

OVERVOLTAGE ON ARRAY OR INVERTER.

690.8 Circuit Sizing and Current.(A) Calculation of Maximum Circuit Current. Themaximum current for the specific circuit shall be calculatedin accordance with 690.8(A)(l) through (A)(4).

(1) Photovoltaic Source Circuit Currents. The maximumcurrent shall be the sum of parallel module rated short­circuit currents multiplied by 125 percent.

(2) PhOtovoltaic Output Circuit Currents. The maximumcurrent shall be the sum ofparallel source circuit maximumcurrents as calculated in 690.8(A)(I).

(3) Inverter Output Circuit Current. The maximumcurrent shall be the inverter continuous output currentrating.(4) Stand-Alone Inverter Input Circuit Current. Themaximum current shall be the stand-alone continuousinverter input current rating when the inverter is producingrated power at the lowest input voltage.

(B) Ampacity and Overcurrent Device Ratings.Photovoltaic system currents shall be considered to becontinuous.

(1) Sizing of Conductors and Overcurrent Devices. Thecircuit conductors and overcurrent devices shall be sized tocarry not less than 125 percent of the maximum currents ascalculated in 690.8(A). The rating or setting of overcurrentdevices shall be permitted in accordance with 240.4(B) and (C).Exception: Circuits containing an assembly, together withits overcurrent device(s), that is listed for continuousoperation at 100 percent of its rating shall be permitted tobe utilized at 100 percent ofits rating.(2) Internal Current Limitation. Overcurrent protectionfor photovoltaic output circuits with devices that internallylimit the current from the photovoltaic output circuit shallbe permitted to be rated at less than the value calculated in690.8(B)(I). This reduced rating shall be at least 125percent of the limited current value. Photovoltaic outputcircuit conductors shall be sized in accordance with690.8(B)(1).

Exception: An overcurrent device in an assembly listedforcontinuous operation at 100 percent of its rating shall bepermitted to be utilized at 100 percent ofits rating.

/

70-548 2007 California Electrical Code

ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS 690.13

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WARNING

SINGLE l20-VOLT SUPPLY. DO NOT CONNECT

MULTIWIRE BRANCH CIRCUITSl

III. Disconnecting Means

690.13 All Conductors. Means shall be provided todisconnect all current-carrying conductors of a photovoltaicpower source from all other conductors in a building orother structure. A switch or circuit breaker shall not beinstalled in a grounded conductor unless that switch orcircuit breaker is part of a ground-fault detection systemrequired by 690.5 and that switch or circuit breaker isautomatically opened and indicated as a normal function ofthe device in responding to ground faults.

(C) Single l20-Volt Supply. The inverter output of astand-alone solar photovoltaic system shall be permitted tosupply 120 volts to single-phase, 3-wire, l20/240-voltservice equipment or distribution panels where there are no240-volt outlets and where there are no multiwire branchcircuits. In all installations, the rating of the overcurrentdevice connected to the output of the inverter shall be lessthan the rating of the neutral bus in the service equipment.This equipment shall be marked with the following wordsor equivalent:

amperes. Higher standard values above 15 amperes forsupplementary overcurrent devices shall be based on thestandard sizes provided in 240.6(A).

(D) Direct-Current Rating. Overcurrent devices, eitherfuses or circuit breakers, used in any dc portion of aphotovoltaic power system shall be listed for use in dccircuits and shall have the appropriate voltage, current, andinterrupt ratings.

(E) Series Overcurrent Protection. In series-connectedstrings of two or more modules, a single overcurrentprotection device shall be permitted.

690.10 Stand-Alone Systems. The premises wiringsystem shall be adequate to meet the requirements of thisCode for a similar installation connected to a service. The

. wiring on the supply side of the building or structuredisconnecting means shall comply with this Code except asmodifIed by 690.10(A), (B), and (C).

(A) Inverter Output. The ac inverter output from a stand­alone system shall be permitted to supply ac power to thebuilding or structure disconnecting means at current levelsbelow the rating ofthat disconnecting means.

(B) Sizing and Protection. The circuit conductors betweenthe inverter output and the building or structuredisconnecting means shall be sized 'based on the outputrating of the inverter. These conductors shall be protectedfrom overcurrents in accordance with Article 240. Theovercurrent protection shall be located at the output of theinverter.

(C) Systems with Multiple Direct-Current Voltages. Fora photovoltaic power source that has multiple output circuitvoltages and employs a common-return conductor, theampacity of the common-return conductor shall not be lessthan the sum of the ampere ratings of the overcurrentdevices of the individual output circuits.

(D) Sizing of Module Interconnection Conductors.Where a single overcurrent device is used to protect a set oftwo or more parallel-connected module circuits, theampacity of each of the module interconnection conductorsshall not be less than the sum of the rating of the singlefuse plus 125 percent of the short-circuit current from theother parallel-connected modules.

690.9 Overcurrent Protection.

(A) Circuits and Equipment. Photovoltaic source circuit,photovoltaic output circuit, inverter output circuit, andstorage battery circuit conductors and equipment shall beprotected in accordance with the requirements of Article240. Circuits connected to more than one' electrical sourceshall have overcurrent devices located so as to provideovercurrent protection from all sources.

Exception: An overcurrent device shall not be requiredforcircuit conductors sized in accordance with 690.8(B) andlocated where one ofthe following apply:

(a) There are no external sources such as parallel­connected source circuits, batteries, or baclifeed frominverters.

(b) The short-circuit currents from all sources do notexceed the ampacity ofthe conductors.

FPN: Possible backfeed of current from any source ofsupply, including a supply tlrrough an inverter into thephotovoltaic output circuit and photovoltaic source circuits,is a consideration in determining whether adequateovercurrent protection from all sources is provided forconductors and modules.

(B) Power Transformers. Overcurrent protection for atransformer with a source(s)on each side shall be providedin accordance with 450.3 by considering fIrst one side ofthe transformer, then the other side of the transformer, aso the primary.

Exception: A power transformer with a current rating onthe side connected toward the photovoltaic power source,not less than the short-circuit output current rating of theinverter, shall be permitted without overcurrent protection

" from that source.o (C) Photovoltaic Source' Circuits. Branch-circuit orsupplementary-type overcurrent devices shall be permittedto provide overcurrent protection in photovoltaic sourcecircuits. The overcurrent devices shall be accessible butshall not be required to be readily accessible.

O Standard values of supplementary overcurrent devicesallowed by this section shall be in one ampere sizeincrements, starting at one ampere up to and including 15

2007 California Electrical Code70-549

690.14 ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS

FPN: The grounded conductor may have a bolted orterminal disconnecting means to allow maintenance ortroubleshooting by qualified personnel.

\

690.14 Additional Provisions. Photovoltaic disconnectingmeans shall comply with 690.l4(A) through 690.l4(D).

(A) Disconnecting Means. The disconnecting means shallnot be required to be suitable as service equipment andshall be rated in accordance with 690.17.

(B) Equipment. Equipment such as photovoltaic sourcecircuit isolating switches, overcurrent devices, andblocking diodes shall be permitted on the photovoltaic sideof the photovoltaic disconnecting means.

(C) Requirements for Disconnecting Means. Means shallbe provided to disconnect all conductors in a building orother structure from the photovoltaic system conductors.

(1) Location. The photovoltaic disconnecting means shallbe installed at a readily accessible location either on theoutside of a building or structure or inside nearest the pointof entrance of the system conductors.

Exception: Installations that comply with 690.31(E) shallbe permitted to have the disconnecting means locatedremote from the point ofentry ofthe system conductors.

IThe photovoltaic system disconnecting means shall not

be installed in bathrooms.

(2) Marking. Each photovoltaic system disconnectingmeans shall be permanently marked to identify it as aphotovoltaic system disconnect.

(3) Suitable for Use. Each photovoltaic systemdisconnecting means shall be suitable for the prevailingconditions. Equipment installed in hazardous (classified)locations shall comply with the requirements of Articles500 through 517.

(4) Maximum Number of Disconnects. The photovoltaicsystem disconnecting means shall consist of not more thansix switches or six circuit breakers mounted in a singleenclosure, in a group of separate enclosures, or in or on aswitchboard.

(5) Grouping. The photovoltaic system disconnectingmeans shall be grouped with other disconnecting means forthe system to comply with 690.l4(C)(4). A photovoltaicdisconnecting memls shall not be required at thephotovoltaic module or array location.

(D) Utility-Interactive Inverters Mounted in Not­Readily-Accessible Locations. Utility-interactive invertersshall be permitted to be mounted on roofs or other exteriorareas that are not readily accessible. These installationsshall comply with (1) through (4):

(1) A direct·current photovoltaic disconnecting meansshall be mounted within sight of or in the inverter.

70-550

(2) An alternating-current disconnecting means shall bemounted within sight of or in the inverter.

(3) The alternating-current output conductors from theinverter and an additional alternating-currentdisconnecting means for the inverter shall comply with690.l4(C)(l).

(4) A plaque shall be installed in accordance with 705.10.

690.15 Disconnection of Photovoltaic Equipment.Means shall be provided to disconnect equipment, such asinverters, batteries, charge controllers, and the like, from allungrounded conductors of all sources. If the equipment isenergized from more than one source, the disconnectingmeans shall be grouped and identified.

A single disconnecting means in accordance with690.17 shall be permitted for the combined ac output ofone or more inverters or ac modules in an interactivesystem.

690.16 Fuses. Disconnecting means shall be provided todisconnect a fuse from all sources of supply if the fuse isenergized from both directions and is accessible to otherthan qualified persons. Such a fuse in a photovoltaic sourcecircuit shall be capable of being disconnectedindependently of fuses in other photovoltaic source circuits.

690.17 Switch or Circuit Breaker. The disconnectingmeans for ungrounded conductors shall consist of amanually operable switch(es) or circuit breaker(s)complying with all of the following requirements:

(1) Located where readily accessible

(2) Externally operable without exposing the operator tocontact with live parts

(3) Plainly indicating whether in the open or closedposition

(4) Having an interrupting rating sufficient for the nominalcircuit voltage and the current that is available at theline terminals of the equipment

Where all terminals of the disconnecting means maybe energized in the open position, a warning sign shall bemounted on or adjacent to the disconnecting means. Thesign shall be clearly legible and have the following wordsor equivalent:

WARNING

ELECTRIC SHOCK HAZARD.

DO NOT TOUCH TERMINALS. TERMINALS

ON BOTH THE LINE AND

LOAD SIDES MAY BE ENERGIZED

IN THE OPEN POSITION.

2007 California Electrical Code

/

690.33

70-551

8687-95

96-104105-113114--122123-131132-140141-158159 176

AmbientTemperature

(OF)

1.000.970.930.890.860.820.770.680.58

1.000.960.910.870.820.760.710.580.41

outdoor use, water resistant, and sunlight resistant.Allowable ampacities shall be in accordance with 400.5.For ambient temperatures exceeding 30°C (86°F), theampacities shall be derated by the appropriate factors givenin Table 690.3l(C).

(D) Small-Conductor Cables. Single-conductor cableslisted for outdoor use that are sunlight resistant andmoisture resistant in sizes 16 AWG and 18 AWG shall bepermitted for module interconnections where such cablesmeet the ampacity req~irements of 690.8. Section 310.15shall be used to determine the cable ampacity andtemperature derating factors.

(E) Direct-Current Photovoltaic Source and OutputCircuits Inside a Building. Where direct currentphotovoltaic source or output circuits ofa utility-interactiveinverter from a building-integrated or other photovoltaicsystem are run inside a building or structure, they shall becontained in metallic raceways or enclosures from the pointof penetration of the surface of the building or structure tothe first readily accessible disconnecting means. Thedisconnecting means shall comply with 690.14(A) through690.14(D).

690.32 Component Interconnections. Fittings andconnectors that are intended to be concealed at the time ofon-site assembly, where listed for such use, shall bepermitted for on-site interconnection of modules or otherarray components. Such fittings and connectors shall beequal to the wiring method employed in insulation,temperature rise, and fault-current withstand, and shall becapable of resisting the effects of the environment in whichthey are used.

690.33 Connectors. The connectors permitted by Article690 shall comply with 690.33(A) through 690.33(E).

(A) Configuration. The connectors shall be polarized andshall have a configuration that is noninterchangeable withreceptacles in other electrical systems on the premises.

1.000.940.880.820.750.670.580.33

Temperature Rating of Conductor

ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS

1.000.910.820.710.580.41

3031-3536-4041-4546-5051-5556-6061-7071-80

AmbientTemperature

COC)

Exception: A connector shall be permitted to be used as anac or a dc disconnecting means, provided that it complieswith the requirements of690.33 and is listed and identifiedfor the use.

690.18 Installation and Service of an Array. Opencircuiting, short circuiting, or opaque covering shall beused to disable an array or portions of an array forinstallation and service.

FPN: Photovoltaic modules are energized while exposed tolight. Installation, replacement, or servicing of arraycomponents while a module(s) is irradiated may exposepersons to electric shock.

2007 California Electrical Code

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o IV. Wiring Methods

690.31 Methods Permitted.

(A) Wiring Systems. All raceway and cable wmngmethods included in this Code and other wiring systemsand fittings specifically intended and identified for use onphotovoltaic arrays shall be permitted. Where wiringdevices with integral enclosures are used, sufficient lengthof cable shall be provided to facilitate replacement.

FPN: Photovoltaic modules operate at elevatedtemperatures when exposed to high ambient temperaturesand to bright sunlight. These temperatures may routinelyexceed 70°C (158°F) in many locations. Moduleinterconnection conductors are available with insulationrated for wet locations and a temperature rating of 90°C(194°F) or greater.

(B) Single-Conductor Cable. Types SE, UF, USE, andUSE-2 single-conductor cable shall be permitted inphotovoltaic source circuits where installed in the samemanner as a Type UF multiconductor. cable in accordancewith Part II of Article 340. Where exposed to sunlight,Type UP cable identified as ;mnlight-resistant shall be used.

(C) Flexible Cords and Cables. Flexible cords and cables,where used to connect the moving parts of tracking PVmodules, shall comply with Article 400 and shall be of atype identified as a hard-service cord or portable powercable; they shall be suitable for extra-hard usage, listed for

o Table 690.31(C) Correction Factors

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690.34 ARTICLE 690 SOLAR PHOTOVOLTAIC SYSTEMS

(B) Guarding. The connectors shall be constructed andinstalled so as to guard against inadvertent contact with liveparts by persons.

(C) Type. The connectors shall be of the latching orlocking type.

(D) Grounding Member. The grounding member shall bethe first to make and the last to break contact with themating connector.

(E) Interruption of Circuit. The connectors shall becapable of interrupting the circuit current without hazard tothe operator.

690.34 Access to Boxes. Junction, pull, and outlet boxeslocated behind modules or panels shall be so installed thatthe wiring contained in them can be rendered accessibledirectly or by displacement of a module(s) or panel(s)secured by removable fasteners and connected by a flexiblewiring system.

690.35 Ungrounded Photovoltaic Power Systems.Photovoltaic power systems shall be permitted to operatewith ungrounded photovoltaic source and output circuitswhere the system complies with 690.35(A) through690.35(G).

(A) Disconnects. All photovoltaic source and output circuitconductors shall have disconnects complying with 690,Part III.

(B) Overcurrent Protection. All photovoltaic source andoutput circuit conductors shall have overcurrent protectioncomplying with 690.9.

(C) Ground-Fault Protection. All photovoltaic source andoutput circuits shall be provided with a ground-faultprotection device or system that complies with (1) through(3):

(1) Detects a ground fault.

(2) Indicates that a gTound fault has occurred

(3) Automatically disconnects the conductors and/or shutsoff the utility-interactive inverter or charge controllerfor that portion of the faulted array

(D) The photovoltaic source and output conductors shallconsist of sheathed (jacketed) multi-conductor cables orshall be installed in a raceway.

(E) The photovoltaic power system direct-current circuitsshall be permitted to be used with ungrounded batterysystems complying with 690.71(G).

(F) The photovoltaic power source shall be labeled withthe following warning at each junction box, combiner box,disconnect, and device where the ungrounded circuits maybe exposed during service:

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WARNINGELECTRIC SHOCK HAZARD. THE DIRECT

CURRENT CIRCUIT CONDUCTORS OF THISPHOTOVOLTAIC POWER SYSTEM ARE

UNGROUNDED BUT MAY BE ENERGIZEDWITH RESPECT TO GROUND DUE TO

LEAKAGE PATHS AND/OR GROUND FAULTS.

(G) The inverters or charge controllers used in systemswith ungrounded photovoltaic source and output circuitsshall be listed for the purpose.

V. Grounding

690.41 System Grounding. For a photovoltaic powersource, one conductor of a two-wire system with aphotovoltaic system voltage over 50 volts and the reference(center tap) conductor of a bipolar system shall be solidlygrounded or shall use other methods that accomplishequivalent system protection in accordance with 250.4(A)and that utilize equipment listed and identified for the use.

Exception: Systems complying with 690.35.

690.42 Point of System Grounding Connection. The dccircuit grounding connection shall be made at any singlepoint on the photovoltaic output circuit.

FPN: Locating the grounding connection point as close aspracticable to the photovoltaic source better protects thesystem from voltage surges due to lightning.

690.43 Equipment Grounding. Exposed non-current­carrying metal parts of module frames, equipment, andconductor enclosures shall be grounded in accordance with250.134 or 250.136(A) regardless of voltage.

690.45 Size of Equipment Grounding Conductor.Where not protected by the ground-fault protectionequipment required by 690.5, the equipment-groundingconductor for photovoltaic source and photovoltaic outputcircuits shall be sized for 125 percent of the photovoltaic­originated short-circuit currents in that circuit. Whereprotected by the ground-fault protection equipmentrequired by 690.5, the equipment-grounding conductors forphotovoltaic source and photovoltaic output circuits shallbe sized in accordance with 250.122.

690.47 Grounding Electrode System.

(A) Alternating-Current Systems. If installing an acsystem, a grounding electrode system shall be provided inaccordance with 250.50 through 250.60. The groundingelectrode conductor shall be installed in accordance with250.64.

(B) Direct-Current Systems. If installing a de system, agrounding electrode system shall be provided inaccordance with 250.166 for grounded systems or 250.169for ungrounded systems. The grounding electrodeconductor shall be installed in accordance with 250.64.

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ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS 690.56

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(C) Systems with Alternating-Current and Direct­Current Grounding Requirements. Photovoltaic powersystems with both alternating-current and direct-current(dc) grounding requirements shall be permitted to begrounded as described in (1) or (2):

(1) A grounding-electrode conductor shall be connectedbetween the identified dc grounding point to a separatedc grounding electrode. The dc grounding-electrodeconductor shall be sized according to 250.166. The dcgrounding electrode shall be bonded to the ac­grounding electrode to make a grounding electrodesystem according to 250.52 and 250.53. The bondingconductor shall be no smaller than the largestgrounding electrode conductor, either ac or dc.

(2) The dc grounding electrode conductor and acgrounding electrode cO~lductor shall be connected to asingle grounding electrode. The separate groundingelectrode conductors shall be sized as required by.250.66 (ac) and 250.166 (dc).

690.48 Continuity of Equipment Grounding Systems.Where the removal of equipment disconnects the bondingconnection between the grounding electrode conductor andexposed conducting surfaces in the photovoltaic source oroutput circuit equipment, a bonding jumper shall beinstalled while the equipment is removed.

690.49 Continuity of Photovoltaic Source and OutputCircuit Grounded Conductors. Where the removal of theutility-interactive inverter or other equipment disconnectsthe bonding connection between the grounding electrodeconductor and the photovoltaic source and/or photovoltaicoutput circuit grounded conductor, a bonding jumper shallbe installed to maintain the system grounding while theinverter or other equipment is removed.

VI. Marking

690.51 Modules. Modules shall be marked withidentification of terminals or leads as to polarity,. maximumovercunent device rating for module protection, and withthe following ratings:

(1) Open-circuit voltage

(2) Operating voltage

(3) Maximum permissible system voltage

(4) Operating current

(5) Short-circuit cutTent

(6) Maximum power

690.52 Alternating-Current Photovoltaic Modules.Alternating-current modules shall be marked withidentification of terminals or leads and with identificationof the following ratings:

(1) Nominal operating ac voltage

2007 California Electrical Code

(2) Nominal operating ac frequency

(3) Maximum ac power

(4) Maximum ac cunent

(5) Maximum overcunent device rating for ac moduleprotection

690.53 Direct-Current Photovoltaic Power Source. Amarking for the direct-cunent photovoltaic power sourceindicating items (1) through (4) shall be provided by theinstaller at an accessible location at the disconnectingmeans for this power source:

(1) Operating cunent

(2) Operating voltage

(3) Maximum system voltage

(4) Short-circuit cunentFPN: Reflecting systems used for ilTadiance enhancementmay result in increased levels of output current and power.

690.54 Interactive System Point of Interconnection. Allinteractive system(s) points of interconnection with othersources shall be marked at an accessible location at thedisconnecting means as a power source with the maximumac output operating cutTent and the operating ac voltage.

690.55 Photovoltaic Power Systems Employing EnergyStorage. Photovoltaic power systems employing energystorage shall also be marked with the maximum operatingvoltage, including any equalization voltage and the polarityof the grounded circuit conductor.

690.56 Identification of Power Sources.

(A) Facilities with Stand-Alone Systems. Any structureor building with a photovoltaic power system that is notconnected to a utility service source and is a stand-alonesystem shall have a permanent plaque or directory installedon the exterior of the building or structure at a readilyvisible location acceptable to the authority havingjurisdiction. The plaque or directory shall indicate thelocation of system disconnecting means and that thestructure contains a stand-alone electrical power system.

(B) Facilities with Utility Services and PV Systems.Buildings or structures with both utility service and aphotovoltaic system shall have a permanent plaque ordirectOly providing the location of the servicedisconnecting means and the photovoltaic systemdisconnecting means, if not located at the same location.

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690.60 ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS

VII. Connection to Other Sources

690.60 Identified Interactive Equipment. Only invertersand ac modules listed and identified as interactive shall bepermitted in interactive systems.

690.61 Loss of Interactive System Power. An inverter oran ac module in an interactive solar photovoltaic systemshall automatically de-energize its output to the connectedelectrical production and distribution network upon loss ofvoltage in that system and shall remain in that state untilthe electrical production and distribution network voltagehas been restored.

A normally interactive solar photovoltaic system shallbe permitted to operate as a stand-alone system to supplyloads that have been disconnected from electricalproduction and distribution network sources.

690.62 Ampacity of Neutral Conductor. If a single­phase, 2-wire inverter output is connected to the neutraland one ungrounded conductor (only) of a 3-wire system orof a 3-phase, 4-wire wye-connected system, the maximumload connected between the neutral and anyoneungrounded conductor plus the inverter output rating shallnot exceed the ampacity of the neutral conductor.

690.63 Unbalanced Interconnections.

(A) Single Phase. Single-phase inverters for photovoltaicsystems and ac modules in interactive solar photovoltaicsystems shall not be connected to 3-phase power systemsunless the interconnected system is designed so thatsignificant unbalanced voltages cannot result.

(B) Three Phase. Three-phase inverters and 3-phase acmodules in interactive systems shall have all phasesautomatically de-energized upon loss of, or unbalanced,voltage in one or more phases unless the interconnectedsystem is designed so that significant unbalanced voltageswill not result.

690.64 Point of Connection. The output of a photovoltaicpower source shall be connected as specified in 690.64(A)or 690.64(B).

(A) Supply Side. A photovoltaic power source shall bepermitted to be connected to the supply side of the servicedisconnecting means as permitted in 230.82(6).

(B) Load Side. A photovoltaic power source shall bepermitted to be connected to the load side of the servicedisconnecting means of the other source(s) at anydistribution equipment on the premises, provided that all ofthe following conditions are met:

(1) Each source interconnection shall be made at adedicated circuit breaker or fusible disconnectingmeans.

(2) The sum of the ampere ratings of overcurrent devicesin circuits supplying power to a busbar or conductorshall not exceed the rating of the busbar or conductor.

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Exception: For a dwelling unit, the sum of the ampereratings of the overcurrent devices shall not exceed 120percent ofthe rating ofthe busbar or conductor.

(3) The interconnection point shall be on the line side ofall ground-fault protection equipment.

Exception: Connection shall be permitted to be made tothe load side of ground-fault protection, provided thatthere is ground-fault protection for equipment from allground-fault current sources.

(4) Equipment containing overcurrent devices in circuitssupplying power to a busbar or conductor shall bemarked to indicate the presence ofall sources.

Exception: Equipment with power supplied from a singlepoint ofconnection.

(5) Circuit breakers, ifbackfed, shall be identified for suchoperation. Dedicated circuit breakers backfed fromlisted utility-interactive inverters complying with690.60 shall not be required to be individually clampedto the panelboard bus bars. A front panel shall clampall Circuit breakers to the panelboard bus bars. Maincircuit breakers connected directly to energized feedersshall also be individually clamped.

VIII. Storage Batteries

690.71 Installation.

(A) General. Storage batteries in a solar photovoltaicsystem shall be installed in accordance with the provisionsof Article 480. The interconnected battery cells shall beconsidered grounded where the photovoltaic power sourceis installed in accordance with 690.41.

(B) Dwellings.

(1) Operating Voltage. Storage batteries for dwellingsshall have the cells connected so as to operate at less than50 volts nominal. Lead-acid storage batteries for dwellingsshall have no more than twenty-four 2-volt cells connectedin series (48-volts nominal).

Exception: Where live parts are not accessible duringroutine battery maintenance, a battery system voltage inaccordance with 690.7 shall be permitted.

(2) Guarding of Live Parts. Live parts of battery systemsfor dwellings shall be guarded to prevent accidental contactby persons or objects, regardless of voltage or battery type.

FPN: Batteries in solar photovoltaic systems are subject toextensive charge-discharge cycles and typically requirefrequent maintenance, such as checking electrolyte andcleaning connections.

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ARTICLE 690 - SOLAR PHOTOVOLTAIC SYSTEMS 690.74

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(C) Current Limiting. A listed, current-limiting, overcurrentdevice shall be installed in each circuit adjacent to the batterieswhere the available short-circuit current from a battery orbattery bank exceeds the intelTIlpting or withstand ratings ofother equipment in that circuit. The installation of current­limiting fuses shall comply with 690.16.

(D) Battery Nonconductive Cases and Conductive I

Racks. Flooded, vented, lead-acid batteries with more than I

twenty-four 2-volt cells connected in series (48 volts,nominal) shall not use conductive cases or shall not beinstalled in conductive cases. Conductive racks used tosupport the nonconductive cases shall be permitted whereno rack material is located within 150 rom (6 in.) of thetops of the nonconductive cases.

This requirement shall not apply to any tYPe of valve­regulated lead-acid (VRLA) battery or any other types ofsealed batteries that may require steel cases for properoperation.

(E) Disconnection of Series Battery Circuits. Batterycircuits subject to field servicing, where more than twenty­four 2-volt cells are connected in series (48 volts, nominal),shall have provisions to disconnect the series-connectedstrings into segments of 24 cells or less for maintenance byqualified persons. Non-load-break bolted or plug-indisconnects shall be permitted.

(F) Battery Maintenance Disconnecting Means. Batteryinstallations, where there are more than twenty-four 2-voltcells connected in series (48 volts, nominal), shall have adisconnecting means, accessible only to qualified persons;that disconnects the grounded circuit conductor(s) in thebattery electrical system for maintenance. Thisdisconnecting means shall not disconnect the groundedcircuit conductor(s) for the remainder of the photovoltaicelectrical system. A non-load-break-rated switch shall bepermitted to be used as the disconnecting means.

(G) Battery Systems of More Than 48 Volts. Onphotovoltaic systems where the battery system consists ofmore than twenty-four 2-volt cells connected in series(more than 48 volts, nominal), the battery system shall bepermitted to operate with ungrounded conductors, providedthe following conditions are met:

(l) The photovoltaic array source and output circuits shallcomply with 690.41.

(2) The dc and ac load circuits shall be solidly grounded.

(3) All main ungrounded battery input/output circuitconductors shall be provided with switcheddisconnects and overcurrent protection.

(4) A ground-fault detector and indicator shall be installedto monitor for ground faults in the battery bank.

690.72 Charge Control.

(A) General. Equipment shall be provided to control thecharging process of the battery. Charge control shall not be

2007 California Electrical Code

required where the design of the photovoltaic source circuitis matched to the voltage rating and charge currentrequirements of the interconnected battery cells and themaximum charging current multiplied by 1 hour is lessthan 3 percent of the rated battery capacity expressed inampere-hours or as recommended by the batterymanufacturer.

IAll adjusting means for control of the charging process

shall be accessible only to qualified persons.FPN: Certain battery types such as valve-regulated lead acidor nickel cadmium can experience thermal failure whenovercharged.

(B) Diversion Charge Controller.

(1) Sole Means of Regulating Charging. A photovoltaicpower system employing it diversion charge controller asthe sole means of regulating the charging of a battery shallbe equipped with a second independent means to preventovercharging of the battery.

(2) Circuits with Direct-Current Diversion ChargeController and Diversion Load. Circuits containing a dcdiversion charge controller and a dc diversion load shallcomply with the following:

(1) The current rating of the diversion load shall be lessthan or equal to the current rating of the diversion loadcharge controller. The voltage rating of the diversionload shall be greater than the maximum batteryvoltage. The power rating of the diversion load shallbe at least 150 percent of the power rating of thephotovoltaic array.

(2) The conductor ampacity and the rating of theovercurrent device for this circuit shall be at least 150percent of the maximum current rating of the diversioncharge controller.

(3) PV Systems Using Utility-Interactive Inverters.Photovoltaic power systems using utility-interactive mvertersto control battery state-of-charge by diverting excess powerinto the utility system shall comply with (l) and (2):

(1) These systems shall not be required to comply with690.72(B)(2). The charge regulation circuits used shallcomply with the requirements of 690.8.

(2) These systems shall have a second, independent meansI

of controlling the battery charging process for usewhen the utility is not present or when the primarycharge controller fails or is disabled.

690.74 Battery Interconnections. Flexible cables, asidentified in Article 400, in sizes 2/0 AWG and larger shallbe permitted within the battery enclosure from batteryterminals to a nearby junction box where they shall beconnected to an approved wiring method. Flexible batterycables shall also be permitted between batteries and cellswithin the battery enclosure. Such cables shall be listed forhard-service use and identified as moisture resistant.

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690.80 ARTICLE 692 - FUEL CELL SYSTEMS

IX. Systems Over 600 Volts

690.80 General. Solar photovoltaic systems with amaximum system voltage over 600 volts dc shall complywith Article 490 and other requirements applicable toinstallations rated over 600 volts.

690.85 Definitions. For the purposes of Part IX of thisarticle, the voltages used to determine cable and equipmentratings are as follows.

Battery Circuits. In battery circuits, the highest voltageexperienced under charging or equalizing conditions.

Photovoltaic Circuits. In dc photovoltaic source circuitsand photovoltaic output circuits, the maximum systemvoltage.

ARTICLE 692

Fuel Cell Systems

I. General

692.1 Scope. This article identifies the requirements forthe installation of fuel cell power systems, which may bestand-alone or interactive with other electrical powerproduction sources and may be with or without electricalenergy storage such as batteries. These systems may haveac or dc output for utilization.

692.2 Definitions.

Fuel Cell. An electrochemical system that consumes fuelto produce an electric current. The main chemical reactionused in a fuel cell for producing electric power is notcombustion. However, there may be sources of combustionused within the overall fuel cell system such asreformers/fuel processors.

Fuel Cell System. The complete aggregate of equipmentused to convert chemical fuel into usable electricity. A fuelcell system typically consists of a reformer, stack, powerinverter, and auxiliary equipment.

Interactive System. A fuel cell system that operates inparallel with and may deliver power to an electricalproduction and distribution network. For the purpose ofthis definition, an energy storage subsystem of a fuel cellsystem, such as a battery, is not another electricalproduction source.

Maximum System Voltage. The highest fuel cell inverteroutput voltage between any ungrounded conductors presentat accessible output terminals.

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Output Circuit. The conductors used to connect the fuelcell system to its electrical point of delivery. In the case ofsites that have series- or parallel-connected multiple units,the term output circuit also refers to the conductors used toelectrically interconnect the fuel cell system(s).

Point of Common Coupling. The point at which thepower production and distribution network and thecustomer interface occurs in an interactive system.Typically, this is the load side of the power network meter.

Stand-Alone System. A fuel cell system that suppliespower independently of an electrical production anddistribution network.

692.3 Other Articles. Wherever the requirements of otherarticles of this Code and Article 692 differ, therequirements of Article 692 shall apply, and, if the systemis operated in parallel with a primary source(s) ofelectricity, the requirements in 705.14,705.16,705.32, and705.43 shall apply.

692.4 Installation.

(A) Fuel Cell System. A fuel cell system shall bepermitted to supply a building or other structure in additionto any service(s) ofanother electricity supply system(s).

(B) Identification. A permanent plaque or directory,denoting all electrical power sources on or in the premises,shall be installed at each service equipment location.

692.6 Listing Requirement. The fuel cell system shall beevaluated and listed for its intended application prior toinstallation.

n. Circuit Requirements

692.8 Circuit Sizing and Current.

(A) Nameplate Rated Circuit Current. The nameplate(s)rated circuit current shall be the rated current indicated onthe fuel cell nameplate(s).

(B) Conductor Ampacity and Overcurrent DeviceRatings. The ampacity of the feeder circuit conductorsfrom the fuel cell system(s) to the premises wiring systemshall not be less than the greater of (1) nameplate(s) ratedcircuit current or (2) the rating of the fuel cell system(s)overcurrent protective device(s).

(C) Ampacity of Grounded or Neutral Conductor. If aninteractive single-phase, 2-wire fuel cell output(s) isconnected to the grounded or neutral conductor and asingle ungrounded conductor of a 3-wire system or of a 3­phase, 4-wire wye-connected system, the maximumunbalanced neutral load current plus the fuel cell system(s)output rating shall not exceed the ampacity of the groundedor neutral conductor.

2007 California Electrical Code