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StraightUp SolarDane GlueckLeo Deering

Josh HillGraham Clinton

Inspiring a Solar Tribe to Create A Sustainable Worldwww.straightupsolar.com

2Inspiring a Solar Tribe to Create A Sustainable World

www.straightupsolar.com

3 NABCEP Certified Installers

2 NABCEP Certified Technical Sales

Licensed Electrical Contractor

300+ Systems / 5+ mW Installed

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Today’s Goals

• Brief Review of Local Market• Concept of Standardization• 2014 NEC Updates• Structural • Fire Protection

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Rapid Growth

Every 80 minutes

Every 4 minutes

Every 83 seconds!

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Missouri’s Status

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• Rebate via Ameren• Funding Allocated

• Court Case Pending• Incentives in Place:

• 30% Fed Tax Credit• Commercial Depreciation

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Concept• Standardization• Safety• Efficiency• Flexibility• Starting point• Resource

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Shared Goals

• Solar Industry & AHJ’s• Safety• Efficiency• Current Best Practices

• 2014 NEC Updates • (Lee Deering)

• Structural • Fire Protection

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NEC 2014The Rapidly Changing PV Industry means the NEC is both reactive and proactive

with mandates for new products, and design and installation methodologies---

what does this mean?

-Adoption date for the latest version of the NEC varies by Jurisdiction!--What

Version are you working under??

-The 2014 NEC - Represents and inclusive, evolving body of knowledge for

installing electrical systems

-Works in conjunction with other Codes and Standards to ensure safety

-Drives design and installation best practices

-Influences manufacturer decisions and product availability

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Article 100 DefinitionsSome definitions relocate to Article 100 - Big Event for Solar!

-Photovoltaic (PV) System and Hybrid System

• Moved from 690 to 100

-Battery System

• Moved from 480 to 100

-Control Circuits

• Added - Carries power when performing it’s function but doesn’t carry

the main power--Applies to the new rapid shutdown

requirements in 690.12(Contactor in the Combiner Box)

-Accessible, readily

- Specifies that having to use a tool means it is not accessible, readily”

- A key is NOT a tool

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Article 690 and 705 Definitions

-Photovoltaic - abbreviated to PV

-Multimode inverter

• Capability to be both “utility interactive” and “stand alone”

-DC-to-DC Converter

• Device in PV source or output circuit that changes DC current and voltage

• Can make voltage higher or lower

• Maximum circuit current = continuous output current

-Direct-current (DC) combiner box

• More than one DC input but just one DC output

• Includes source circuit and output circuit

combiners

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110.21(B):Field Applied Hazard Markings

-Caution, warning and danger labels/signs/directories

• Adequately warn hazard with effective color, wording and symbols

• Permanently affixed and suitable for the environment

• No handwriting, unless subject to change

• Important to know what the AHJ wants

-Two Informational Notes: reference ANSI Z535.4-2011

- Product Safety Signs and Labels

-Best practice!

-Individual labeling requirements in 690.31(G)(4) DC Raceway and

690.56(B) Rapid Shutdown –

• Font size and color• Color scheme and reflectivity

• Mimics 2012 IFC requirements

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The Change to 1000 V

-Nearly code-wide, with some exceptions• Around 100 of 120 proposals were accepted (on going process)

-Examples of some the changes• Article 490: definition of “High Voltage” now > 1,000 V (changed)

• Workspaces clearances (Did Not Change)

* 110.26(A): systems up to 600 V

* 110.34(A): systems 601 V and up

• PV systems over 1000V (600 volt changed)

* Article 690 Part IX

-In large part driven by PV Systems• Doesn’t “change” existing equipment/tools listing & ratings

-1 and 2 family dwellings• 600 Vdc max. system voltage per 690.7(C)

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SUITABLE FOR BACKFEEDING:

DEVICES MARKED “LINE AND LOAD”-Changes and ‘clarifications’• 690.10(E) - Stand-alone systems

* Do NOT back feed breakers marked line load

• 690.17(A) -Manually operable disconnect types

* Informational note: “Fused disconnects, unless otherwise marked,

are suitable for back feeding.” --Referenced circuit breakers in 2011

-The moral of the story?• Consult the Manufacturer

* AFCI, GFDI, breakers, switches - may be able to be backfed

# Have they been tested? Is there a standard to list to?

• As always, consult with your AHJ !

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690.8 AND 690.9CONDUCTOR AND OCPD SIZING

-Sizing of conductors and OCPD reorganized

-690.8(B); Conductors must be sized • 125% of maximum current (690.8(A) ) before

application of adjustment/conditions of use factors

*Or

• Maximum current (690.8A) after application of

adjustment/conditions of use factors

-690.9(B): OCPD minimum size = maximum circuit

current x 1.25

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690.15(C): Disconnects for Roof DC Combiner Boxes

-Rooftop DC combiners must have disconnect• Load-break rated switch on PV output circuit

• Within 6 feet of or integrated into the combiner

• Can be remote controlled * Must be also locally controlled

• Works in conjunction with 690.12 rapid shutdown

requirements

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Shared Goals

• Solar Industry & AHJ’s• Safety• Efficiency• Current Best Practices

• 2014 NEC Updates • (Josh Hill)

• Structural • Fire Protection

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NEC 2014

Arc-Fault Protection 690.11: Required for all DC systems >= 80 Vdc• Options: DC combiner boxes, String

Inverters, DC-to-DC converters

705.12(D)(6): Required for AC output circuits of AC Modules and Microinverters not in raceways• Options: Integrated into microinverter, AFCI circuit

breaker suitable for backfeeding

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NEC 2014

Rapid System Shutdown: 690.12 • Within 10 seconds, de-energize all

conductors to 30V or less and 240VA or less• As measured between any two conductors and

between any conductor and ground

• All DC PV circuits, inverter AC circuits and all multimode inverter circuits if:

• More than 10 ft from PV array• Longer than 5 ft and inside building

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NEC 2014Rapid Shutdown Implementation: Grid-Tied PV• All grid tied inverters shut-down AC automatically

after loss of utility power (UL 1741, IEEE 1547):• Solar AC disconnect opened, meter pulled or

Main service disconnect opened• DC circuits handled by following options:

• Inverters located on Roof within 10’ of array (microinverters as well as string inverters)

• DC-to-DC Converters (aka DC Optimizers. i.e. Tigo, Solar Edge, and other manufacturers)

• Relay/Contactor combiner boxes within 10’ of array (i.e. MidNite Solar “Birdhouse”)

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NEC 2014Rapid Shutdown Implementation: Multimode PV (Grid-Tied + Battery Backup)• PV does NOT shut-down on loss of utility power• Therefore, we need separate switch to remotely

open multiple disconnects (i.e. relays)• PV DC conductors (more than 10’ from array)• Inverter output to backup load panel• Battery inputs to inverter (if longer than 5’)

Additional equipment and methods of meeting rapid shutdown requirements expected in the future.

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NEC 2014Additional Auxiliary Grounding Electrodes: 690.47(D)• Introduced in 2008 NEC• Deleted in 2011 NEC (accidentally)• Added back to 2014 code with confusing

and potentially dangerous wording• Added “Auxiliary” (i.e. optional)• References 250.54 which state that

auxiliary (optional) grounding electrodes do not need to be bonded to the building grounding electrode system

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NEC 2014Additional Auxiliary Grounding Electrodes: 690.47(D)• Bill Brooks and Mike Holt recommend this section

be removed• Suggest if AHJ requires auxiliary (optional)

electrode, be sure to bond back to primary electrode system at ground level (not via DC EGC that goes up over roof and down through house to AC GEC).

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NEC 2014Additional Auxiliary Grounding Electrodes: 690.47(D)• (D) for Danger?

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NEC 2014705.12(D): Load Side Connections• Calculations now based on max inverter

output current*1.25 rather than backfed circuit breaker size

• Different calculations for • Feeders• Taps• Busbars• AC combiner panels

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NEC 2014705.12(D)(2)(1)(a): Feeder Connections

METER

200A

1000A

1000A BUS

INVERTERImax =

160A 200A

MLO

200A BUS

200A Feeder 60A

60A

60A

60A

60A

60A

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NEC 2014705.12(D)(2)(1)(a): Feeder Connections

METER

200A

1000A

1000A BUS

INVERTERImax =

160A 200A

MLO

400A BUS

200A Feeder 60A

60A

60A

60A

60A

60A

400A Feeder

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NEC 2014705.12(D)(2)(1)(b): Feeder Connections

METER

200A

1000A

1000A BUS

INVERTERImax =

160A 200A

MLO

200A BUS

200A Feeder 60A

60A

60A

60A

60A

60A

200A Feeder

200A

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NEC 2014705.12(D)(2)(2): Tap Connections

METER

200A

1000A

1000A BUS

INVERTERImax =

160A 200A

100A

100A BUSSubpanel

200A Feeder 60A

60A

60A

60A

60A

60A

<= 10’Tap

(125% Inverter Imax + Feeder OCPD)*0.10 = (192+200)*.1=39AMin 100A due to subpanel OCPD

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NEC 2014705.12(D)(2)(3)(a): Busbar ConnectionsSources do not exceed 100% busbar rating• Inv Imax*1.25 + Primary source OCPD <= busbar rating

Ex:• 125A busbar• 100A main• Inverter Imax*1.25 = 20A*1.25= 25A• 25+100 <= 125A busbar

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NEC 2014705.12(D)(2)(3)(b): Busbar ConnectionsSources exceed 100% busbar rating but do not exceed 120% of busbar rating (120% Rule)• Inv Imax*1.25 + Primary source OCPD <= busbar rating*1.2• Inverter OCPD required to be at opposite end of busbar from

main source connection• “Warning Do Not Relocate Breaker” label required

Ex:• 100A busbar*1.2 = 120A• 100A main• Inverter Imax*1.25 = 16A*1.25= 20A• 20+100 <= 120A

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NEC 2014705.12(D)(2)(3)(c): Busbar ConnectionsSum of all OCPD’s (excluding primary source OCPD) shall not exceed busbar rating.• AC Combiner Panel• Warning label required

• “Total Rating … Shall not Exceed …”Ex:• 100A busbar• 100A main• 4 x 20A inverter OCPD’s (80A)• 1 x 20A datalogger breaker• 80+20 <= 100A bus bar rating

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Shared Goals

• Solar Industry & AHJ’s• Safety• Efficiency• Current Best Practices

• 2014 NEC Updates • Structural (Graham Clinton)• Fire Protection

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Structural General Background of the Changing Code

• IBC • Chapter 15 - Focused on differences between

Adhered, PV Shingles, and Racking Systems• Chapter16 Structural Design and Wind Loads

• IRC • Chapter 9 - Roof Assemblies• Chapter 23 - Solar Thermal

• ASCE 7-05/10 Chapter 6• Typically cited by structural engineers and

specifically mentioned in IBC as an acceptable reference for load calculation

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Structural Concerns of the Code

• Primarily concerned with Seismic, Wind, Snow and Dead Loads

• Review ensures a structure can withstand these loads• Other key points:

• Manufacturer recommendations must be followed• Materials must be appropriate for the roof• Roof must be capable of supporting the system• System is designed to prevent leaks• Labels and setbacks requirements are followed per

NEC and IFC

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Structural

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General Background for Different Types of Solar

• Adhered – are tested by the manufacturer and depend on the wind loads assigned by them

• Shingles and other building integrated solar (BIPV) are tested like shingles

• Racking systems are components that require independent testing by the manufacturer

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Structural Three Common Systems – Flush Mounted

• Designed for steep roofs • Fixed – Parallel to Roof Plain (typical residential)• Modules are supported by rails that are attached to a

standoff mounting device• The standoff mounts are screwed into rafters and are

flashed underneath the shingles to prevent leakage

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Structural

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Three Common Systems – Ballasted

• Used on flat roofs• Tilted from Roof Plain (typical commercial)• Resists wind and seismic forces uses the weight of

ballast blocks and friction• Sometime code officials

require roof penetrating attachments

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Structural

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Three Common Systems – Ground Mounted

• Supported by a pole or ballast system on ground• Pole mounted systems are placed in cement piers to

support the pole • Racking system is attached to the pole to support

modules• Ballasted systems typically

only require a gravel padto promote drainage andprevent plants blocking thearray

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Structural Wind Loads

• IBC 1609.6 or ASCE 7

• Wind speed and exposure category are defined • Typically designed to 90 mph in St. Louis region• Manufacturers design according to models

generated from detailed wind tunnel testing• This is the recommended method for wind design• ASCE does not provide a prescriptive approach to

design

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Structural ASCE Does not Address Ballasted SystemsMWFRS or Cladding Calculation – or Both

• The Main-Wind Force Resisting System (MWFRS)” is defined by ASCE as “an assemblage of structural elements assigned to provide support and stability for the overall structure

• Components and cladding” is defined by ASCE as an “element of the building that does not qualify as the MWFRS”

• Components and Cladding – Mostly concerned with solid elements such as chimneys and air conditioners

• Diverges significantly from air-permeable components like tilted modules which both transfer loads and experience uplift

• Thus engineers and officials often try a hybrid of the two

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Structural Is a Structural Engineer/Architect needed?

• A structural analysis is needed for large commercial projects or non-standard residential

• They can determine if a structure can support solar• Ballasted systems are designed and engineered by

the manufacturer• Typically based upon wind tunnel testing in

accordance with ASCE 31.6.3 Peer Reviewed Wind Tunnel and SEAOC PV1 / SEOAC PV2

• Sometimes local jurisdictions require additional attachments over wind or seismic concerns

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Structural

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Structural Wind/Seismic Resources to Address Code Gaps

• Structural Engineer Association of California - SEAOC Committees• Incorporated into the California Code

• Solar ABC’s – Technical papers to guide engineers.• Technical Papers – describe proper wind tunnel

studies, CFD use, etc.• Wind tunnel studies/Shake Table Tests – on going,

specific to each manufacturer

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Shared Goals

• Solar Industry & AHJ’s• Safety• Efficiency• Current Best Practices

• 2014 NEC Updates • Structural• Fire Protection

(Graham Clinton)

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Fire SafetyGeneral Background of the Changing Code

• California Served as the Basis for the 2012 IFC• They recommend that arrays occupying less than 50%

of the available roof space be excluded from review• Likely to offer sufficient venting opportunities

• The Solar America Board for Codes and Standards (SOLAR ABCs) and Bill Brooks have detailed this process and the intent in “Understanding the Cal Fire Code”

• http://www.solarabcs.org/about/publications/reports/fireguideline/

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Fire SafetyGeneral Background of Code Changes

• California is a good reference - most developed solar market in the US

• First to adopt fire restrictions on solar arrays• Nearly half of CA fire departments, if allowed, exclude

solar from review – minimal risk• There are draft proposals that would expand the

exemption for arrays – helps minimize soft costs• Anticipated to provide exemptions for nearly half of

all residential solar projects

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Fire Safety2012 Fire Code

• Primarily concerned with setbacks and firefighter access

• Rooftop disconnects were excluded because of the false sense of security that they could provide to firefighters – never cut into conduit

• Addressed directly by the 2014 NEC – rapid shutdown• Conduit must be:

• 10’ below roof or under structural member• Except where directly under the array

• Exposed wires on roof must be in marked conduit

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Fire SafetyResidential Design - ExceptionsLocal jurisdictions may create exceptions to this requirement where access, pathway or ventilation requirements are reduced due to:

• Proximity and type of adjacent exposures• Alternative access opportunities (as from adjoining

roofs)• Ground level access to the roof area in question

• Group U non-habitable structures like garages excluded from setbacks and access paths

• Flat roofs below 2:12 have standard 3’ perimeter

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Fire SafetyHip Roof Layouts

605.11.3.2.1 Residential buildings with hip roof layouts.

Panels/modules installed on residential buildings with hip roof layouts shall be located in a manner that provides a 3-foot-wide (914 mm) clear access pathway from the eave to the ridge on each roof slope where panels/modules are located. The access pathway shall be located at a structurally strong location on the building capable of supporting the live load of fire fighters accessing the roof.

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Fire SafetySingle Ridge (Gable)

605.11.3.2.2 Residential buildings with a single ridge.

Panels/modules installed on residential buildingswith a single ridge shall be located in a mannerthat provides two, 3-foot-wide (914 mm) accesspathways from the eave to the ridge on each roofslope where panels/modules are located.

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Fire Safety

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Hips and Valley

605.11.3.2.3 Residential buildings with roof hips and valleys.

Panels/modules installed on residential buildingswith roof hips and valleys shall be located nocloser than 18 inches (457 mm) to a hip or avalley where panels/modules are to be placed onboth sides of a hip or valley. Where panels are tobe located on only one side of a hip or valley thatis of equal length, the panels shall be permittedto be placed directly adjacent to the hip or valley.

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Fire SafetyCommercial Design

• Fire officials may determine a commercial building is equivalent to a residential structure

• Arrays shall be no greater than 150 feet x 150 feet • Creates opportunities for fire department smoke

ventilation operations.• Flat roof with no dimensions over 250’ require 4’

perimeter• Flat roof with a dimension over 250’ require 6’

perimeter• Dual axis path – typically on arrays over 150’

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Fire Safety

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Commercial Venting Design - Pathways

Smoke ventilation options between array sections shall be one of the following:

• 2.1. A pathway 8 feet or greater in width.• 2.2. A 4-foot or greater in width pathwayand bordering roof skylights or smoke andheat vents.• 2.3. A 4-foot or greater in width pathwayand bordering 4-foot by 8-foot "ventingcutouts” every 20 feet on alternating sidesof the pathway.

• Saw tooth style cutouts

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Fire Safety

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>250’ Roof Design with 6’ Perimeter

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Fire Safety

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<250’ Roof Design with 4’ Perimeter

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StraightUp Solar10330 Page Industrial Blvd.

St. Louis, MOinfo@straightupsolar.com

Inspiring a Solar Tribe to Create A Sustainable Worldwww.straightupsolar.com