Westinghouse AC System User manual

Rev: 10-12-11
AC System Installation Guide
V2 60 Cell Modules

Westinghouse Solar AC Installation Guide
Copyright © 2011 - Westinghouse Solar
Copyright © 2011. Westinghouse Solar. All rights reserved.
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For permission contact: Westinghouse Solar, 1475 South Bascom Ave. Suite 101, Campbell, CA 95008, Attn: VP of
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Trademarks: Westinghouse Solar, Westinghouse Solar Power Systems, Sun for Everyone, and related trade dress
are trade names, trademarks or registered trademarks, and may not be used without written permission.
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AND THEIR EMPLOYEES, AGENTS, OFFICERS AND DIRECTORS (COLLECTIVELY “AUTHOR”) MAKE NO
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OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES
OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES,
PROMOTIONAL MATERIALS OR CUSTOMER SERVICE. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY
NOT BE SUITABLE FOR EVERY SITUATION. THE CONTENTS OF THIS WORK ARE INTENDED FOR A TARGET
AUDIENCE THAT HAS SOME BASIC CONSTRUCTION AND ELECTRICAL WIRING KNOWLEDGE. THIS WORK IS SOLD
WITH THE UNDERSTANDING THAT THE AUTHOR IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR
OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT
PROFESSIONAL PERSON SHOULD BE SOUGHT. IN VIEW OF THE CHANGES IN LOCAL, STATE AND FEDERAL
REGULATIONS, THE READER IS URGED TO REVIEW AND EVALUATE THE INFORMATION PROVIDED BY THEIR
LOCAL, STATE AND FEDERAL REGULATORY AUTHORITY FOR, AMONG OTHER THINGS, ANY RULES, REGULATIONS,
INSTRUCTIONS, REQUIREMENTS, OR PRECAUTIONS RELATED TO THE INSTALLATION OF PV SOLAR ELECTRIC
SYSTEMS. READERS SHOULD CONSULT A LICENSED SOLAR INSTALLATION CONTRACTOR OR ELECTRICIAN WHERE
APPROPRIATE. THE AUTHOR SHALL NOT BE LIABLE FOR DAMAGES ARISING HEREFROM.
Place of Origin. This manual, and the techniques, methods and IP contained within it, were created in the United
States of America. Westinghouse Solar AC Systems contain some foreign made components. Assembly, design and
distribution takes place through operations located within and outside the United States of America.
Protected by U.S. patents (7,406,800; 7,832,157, 7,866,098 and 7,987,641), and foreign patents (2,005,248,343;
243,626; 274,182 and 751,614). Other patents pending.

Westinghouse Solar AC Installation Guide
Copyright © 2011 - Westinghouse Solar
Table of Contents
Section I. Getting Started ...................................................................................................................1
1. Safety Precautions ............................................................................................................................ 1
2. Parts and Tools.................................................................................................................................. 1
3. Solar Power Basics ............................................................................................................................ 2
4. Using this Guide ................................................................................................................................ 3
Section II. Westinghouse Solar AC System Layout and Design..............................................................5
1. Westinghouse Solar Roof Layout Site Surveys.................................................................................. 7
2. Drafting a Roof Layout ...................................................................................................................... 7
3. Elements of Designing a Solar System Specific to Westinghouse Solar AC Panels........................... 8
4. Westinghouse Solar Mounting and Structural Requirements........................................................10
5. Drafting a Solar Array...................................................................................................................... 12
Section III. Creating an Electrical Diagram ........................................................................................14
1. Westinghouse Solar AC Electrical Requirements............................................................................ 14
2. Single line diagram preparation...................................................................................................... 15
3. Electrical Line Diagram.................................................................................................................... 16
4. Grounding .......................................................................................................................................16
Section IV. Installation .....................................................................................................................18
1. Safety Warnings ..............................................................................................................................18
2. Layout.............................................................................................................................................. 18
3. Mounting......................................................................................................................................... 21
4. Module Installation......................................................................................................................... 23
5. Connecting Westinghouse Solar AC Wiring Harnesses................................................................... 26

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Copyright © 2011 - Westinghouse Solar
6. Grounding .......................................................................................................................................29
7. Adding AC Interconnect Parts ......................................................................................................... 30
8. Commissioning Westinghouse Solar AC Systems ...........................................................................31
Section V. Westinghouse Solar Operations .......................................................................................33
1. Troubleshooting..............................................................................................................................33
2. Troubleshooting an Inoperable Inverter (For Experienced Installers)............................................34
3. Disconnecting the Inverter from the PV Panel ............................................................................... 34
Section VI. Definitions......................................................................................................................35
Section VII. Appendix ......................................................................................................................... i
Section VIII. Technical Support ........................................................................................................xiii
Table of Figures .............................................................................................................................. xiv

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Section I. Getting Started
1. Safety Precautions
•Before installing the Westinghouse Solar AC Module, read all instructions and cautionary
markings in the Westinghouse Solar AC documentation.
•Perform all electrical installations in accordance with all local electrical codes, the National
Electrical Code (NEC), ANSI/NFPA 70 and local utility requirements.
2. Parts and Tools
Required tools include:
Splice Driver (WHS provided)
Splice Driver
(Available from Westinghouse Solar)
1/4” Ratchet Wrench
(Available from any tool source)
9/16” Combination Wrench
(available from any tool source)
Offset Bracket
Grounding Washer

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3. Solar Power Basics
Background
Rooftop solar power systems have come a long way, and Westinghouse Solar AC panels break new
ground in both performance and safety. Westinghouse Solar AC panels are the first solar panel on
the market to integrate racking, wiring, grounding and inverters directly into the panel. This
section provides an overview of the installation and operation of your Westinghouse Solar Power
System. Please note that the instructions herein are directed towards individuals and
professionals with good knowledge of residential wiring and construction techniques. Do not
undertake the wiring and installation of this product if you are not qualified to work with
household AC voltages, if you are not knowledgeable about construction techniques, and if you
are not experienced in working on rooftops and other dangerous locations.
Figure 1 -– Westinghouse Solar AC System
How Westinghouse Solar AC Works
Westinghouse Solar AC panels are installed on a sunny, generally south-facing rooftop or back
yard area. AC output from the solar panels is wired into your home’s electrical service panel via a
dedicated 240 VAC branch circuit. When direct sunlight hits Westinghouse Solar panels, their
built-in inverters produce AC power synchronized to the utility’s grid. This power goes towards use
in your home first. When you produce more electricity on your roof than your home needs, the
excess flows to the grid, running your electric meter backwards. At night or on cloudy days you

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still draw power from your utility. Your electric bill is reduced because you only pay for the net
amount of electricity you use.
Westinghouse Solar AC Panel Design and Performance
Ordinary solar power systems use a centralized inverter, and require the installation of a separate
racking system to mount the panels. These ordinary systems also require manual interconnection
of high voltage DC wiring, and manual grounding of all panel and racking components. With the
racking, wiring, grounding and inverters built into Westinghouse Solar panels, installation is much
easier, reliability is greater and performance is 5 to 25% higher than ordinary systems.
The rating on each panel indicates the nominal DC power output in watts of a panel when it is in
bright sunlight in 25 degree C conditions, and the sun’s rays are perpendicular to the surface of
the panel. Because the inverter operates at about 95% efficiency, the AC output of the system will
be approximately 5% less than the peak DC output. So at peak conditions, a 235 watt
Westinghouse Solar AC panel will produce up to about 223 watts of power. In real world
conditions throughout the day, as the sun rises, moves across the sky, and then sets, the output of
the panels will increase from essentially zero at dawn to a peak of about 175-214 watts
(depending on season, sun angle, mounting angle and roof orientation), and then decline again to
zero. Each panel operates independently, so if one is shaded or dirty the adjacent panels will still
operate to maximize their energy output.
Westinghouse Solar AC panels use Enphase micro-inverters, which are mounted on the back of
each panel. The easiest way to determine the output from your Westinghouse Solar AC panels is
with the optional Energy Management Unit (EMU). The EMU communicates with Enphase’s
“Englighten” website for real time reporting and analysis on the performance of each of your
Westinghouse Solar panels. The EMU is installed by plugging it into any convenient 120 VAC wall
socket and providing an Ethernet connection to your broadband router or modem. After
installation of the EMU, the full network of Westinghouse Solar AC Panels automatically begins
reporting to Enlighten. Alternatively, you may measure the voltage, current and power output of
each branch circuit of Westinghouse Solar AC panels with conventional electrical instruments,
taking the appropriate cautions when handling live electrical circuitry.
4. Using this Guide
This guide will familiarize you with the fundamentals of design and installation of your
Westinghouse Solar Power System. The guide also serves to illustrate the simplicity and
efficiency of solar design when equipment is developed in unison with each other. Westinghouse
Solar Power Systems consist of hundreds of individual separate parts built into one integrated
solar electric system delivering easier, faster design and installation over ordinary solar
installations.
This guide contains three primary sections. The first section covers the physical properties of solar
design specific to the Westinghouse Solar Power System, including how to layout your
Westinghouse Solar Power System, how to choose components, and the structural requirements

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involved in the installation process. The second section of this guide covers the creation of an
electrical diagram, electrical site surveys, and elements of designing a solar system specific to
Westinghouse Solar AC panels. Common requirements for solar electrical permit applications are
also reviewed. The final section reviews Westinghouse Solar AC installation best practices and
system commissioning. If you are familiar with residential construction techniques, AC wiring, and
your local permitting requirements you will have the basic skills to install your Westinghouse Solar
Power System. Please note that certain state incentive programs and utility interconnection
regulations may require skills and instruments beyond those noted above, in which case the
services of a professional solar installer may be needed.
The convention we use to describe the orientation of Westinghouse Solar layouts in this guide is
that the north/ south direction describes rows of panels that are aligned vertically where north is
the peak of the roof, and south refers to the gutter. An east / west row describes a horizontal
grouping of panels from left to right. There are different functions that need to be considered
when designing Westinghouse Solar in regards to the horizontal and vertical connection of panels.
Note:
This guide was created by summarizing common requirements of solar design. It serves to prepare
system designers with a basic understanding of the solar design and planning process. Designers are
encouraged to research the specific demands of the permitting jurisdiction and utility governing their
region. Your installation should be performed in full compliance with OSHA safety standards and all
relevant jurisdictional requirements, including if applicable, the U.S. National Electrical Code (“NEC”).

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Section II. Westinghouse Solar AC System Layout and Design
Westinghouse Solar AC systems require 80% fewer parts than ordinary solar systems; the simplicity of
having fewer parts transfers directly into the ease of the design process. Along with the added
efficiencies of Westinghouse Solar AC panels comes a set of unique parameters that need to be
considered when laying out your design. Westinghouse Solar’s racking system is built directly into the
panel frame. When laying out a single row you should visualize the perimeter of the array for your roof
attachment points. The top and bottom frames of Westinghouse Solar panels is where the "Groove”
(Figure 2) is accessible and will serve as connection between the array and the chosen roof-mounting
solution. The Groove provides full adjustability in the east-west direction of your roof, allowing you to
adapt attachment spacing to nearly every rafter scenario.
Figure 2 -Roof attachment components and panel Groove example for composition shingle roof
You may orient the Westinghouse Solar panels in either a “portrait mode” or a “landscape mode”.
Portrait mode minimizes roof penetrations and AC wiring, resulting in faster installation times.
Landscape mode may also be used for added flexibility. The design of the Westinghouse Solar Power
System also accommodates mixed portrait and landscape installations.

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Figure 3 –Six by two array installed in portrait mode
Figure 4 - Comparably sized four by three array in landscape mode

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1. Westinghouse Solar Roof Layout Site Surveys
Prepare for the roof layout by surveying your roof to gather the following design information:
A. Roof type. The most common roof type is composition asphalt shingle. Flat Concrete tile
and barrel tile roofs are also compatible with Westinghouse Solar AC panels. This
information will determine your specific roofing kit needed. We have included roof
attachment profiles that can be included in your plans in the appendix of this guide.
B. Underlying structure. Determine the dimension of rafters and the spacing of the rafters.
For example, 2"x 8" @ 24" o.c. describes 2" by 8" rafters that are spaced 24" on center.
This information will determine where you locate your attachment points on your roof
layout. Also, planning departments typically will not ask you to draw individual rafters on
your submitted layout, but they will need this information noted on the plans to confirm the
structure meets code requirements.
C. Roof Pitch. Measure the pitch of your roof in degrees.
D. Roof measurements. Take accurate measurements that can easily be transferred onto a
sheet of graph paper or into the CAD program you are working with to design the layout.
Remember to include any obstacles that will interfere with your array design. When
measuring the peak of the roof, exclude the roof cap in your measurements because this is
an unusable area for solar attachments.
E. Azimuth. This information will help you choose the optimal solar roof surfaces, and is also
crucial to include on documentation when applying for state rebates and incentives. Ideal
orientation is south, but east and west facing roofs are OK with only a slight output penalty.
Panels are designed for flush roof mounting at your existing roof slope.
F. Shading. Using a SunEye or Solar Pathfinder device, determine shading and design a layout
that will maximize system output.
2. Drafting a Roof Layout
This portion of the process can be done using a graph paper or in a more detailed tool such as a
CAD program. Before submitting your layout to your local permitting jurisdiction, request
information from your local building permit office on special requirements for PV design in your
area. These requirements may include roof setbacks and clearances that need to be included in
your design.

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Figure 5 - Sample roof layout and panel dimensions
3. Elements of Designing a Solar System Specific to Westinghouse Solar AC Panels
Before you add the solar array to your roof layout design become familiar with the basic design
principles specific to Westinghouse Solar AC. You should understand the spacing requirements,
mounting methods, and wiring basics that are a part of the Westinghouse Solar AC design. You will
need to follow the equipment specific rules below in order to create a safe and efficient
Westinghouse Solar AC system.
-Westinghouse Solar AC Branch Circuits. -When Westinghouse Solar AC panels are arranged on
a roof layout, they are wired in parallel, and operate independently on a per panel basis. For
this reason, panels can be placed on roofs of varying pitches, orientations, and shading levels.

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Unlike with ordinary DC solar panels, the performance of Westinghouse Solar panels will not be
compromised by adjacent lower producing panels in the same branch circuit.
-Include Buffer Space Around the Array in your Design. Consider the necessary buffer room
needed around the array for the roof mount to be sufficiently “flashed.” To be flashed is a
roofing term for professionally sealing a penetration by installing a separate metal flashing
underneath the row of shingles above the penetration, as illustrated below. Concrete tile and
barrel tile dimensions are shown in the Appendix.
Figure 6 - Roof top buffer room example on composition shingle roof
Use an Offset L Bracket when modules connect over an attachment point. The Offset L Brackets
allow you to secure two modules together with a splice over an attachment point. Use the
Offset L Bracket instead of a regular L Bracket for an additional 2 inches of mounting flexibility.
Figure 7 - Offset L Bracket

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4. Westinghouse Solar Mounting and Structural Requirements
To satisfy Westinghouse Solar's minimal structural requirements there are two simple design rules
that usually dictate the minimum mounting requirements. As Westinghouse Solar AC panels are
connected together they form a rigid structure. The span of the panels between roof attachments
is generally 48”. As per the Technical Engineering Report (available on WestinghouseSolar.com,
greater spans can be used in sheltered wind condition areas, and shorter spans may be necessary
under high wind conditions. These roof attachments are located on both the top and bottom of
your single row array. The second rule requires that panels which overhang the last footing in a
row may stick out no more than a maximum of 16" from that footing. Before finalizing your roof
drawing, check with your local building department to identify any unique wind or snow load
requirements that pertain to your jurisdiction. A combination of shortening the maximum span
between roof attachments and increasing the length of your lags will enhance the wind load
rating of Westinghouse Solar AC panels.Refer to the Technical Engineering Report on
www.westinghousesolar.com to determine maximum allowable anchor spacing.
Figure 8 - Basic Westinghouse Solar attachment point layout
(Refer to Technical Engineering Report on www.westinghousesolar.com)

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Warning: The Westinghouse Solar AC Solar Panel System must be mounted over a fire
resistant roof covering rated for the application. Attachment points must be properly located
relative to the panel so the brackets do not exert lateral pressure on the frame. Care should
be taken to ensure the mounting points are positioned in accordance with the Westinghouse
Solar AC panel requirements. The measurements in the following diagrams represent distance
between lag bolt penetrations. Westinghouse Solar L-brackets feature an adjustable oblong
base slot that is adjusted to exact panel dimensions as the system is installed. Failure to
adjust the L-Brackets and associated hardware to the exact panel dimensions may cause the
hardware to exert lateral pressure on the Westinghouse Solar Frame voiding the warranty.
Shared Attachment Points
Westinghouse Solar roof layouts that include multiple rows of panels leverage the installation
efficiencies of panel-integrated racking. The stainless steel Westinghouse Solar splices
(Connectors) that ground and connect panels in the east-west direction serve as structural
components. The North-South Bracket serves as a structural connection and enables sharing of
footings between the first and second rows (and all consecutive rows until the top of array).
The Westinghouse Solar North-South Bracket allows the upper row to share the lower rows
upper footing. The Westinghouse Solar AC Solar Power System has been tested and certified at
an accredited laboratory as an integrated system. When designing a multiple row array with
Westinghouse Solar AC, the entire array can be seen as a unified structure, and not single rows
of panels on independent racking systems as with ordinary solar panels.
Figure 9- Profile of roof attachments with shared center attachment point across two panel rows

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5. Drafting a Solar Array
Begin drawing Westinghouse Solar panels on the predetermined solar roofs considering the above
mentioned design parameters. Westinghouse Solar AC panels measure 65.3" long by 39.3” wide.
Include a 1" gap between rows in the north/ south direction to accommodate the installation of the
Westinghouse Solar North-South Bracket. To allow for thermal expansion in large arrays, include a
one inch expansion gap for every 12 Westinghouse Solar panels in a continuous row.
Take time to review how the Westinghouse Solar components you are working with are
developed and organized in the included roof layout. The default roof attachment profiles
included in the Appendices may be attached to your plans for review by local planning and
permitting jurisdictions.
Figure 10 - Westinghouse Solar inter-panel spacing and panel dimensions
Adding Additional Equipment to the Roof Layout
Westinghouse Solar AC Wire Runs
After the roof layout is complete with Westinghouse Solar AC panel locations and the existing
electrical service, identify where conduit or Romex will be run to route the arrays conductors to
the associated equipment on the ground. This can be done by simply drawing a line across your
site map and labeling the material as is seen in the sample roof layout.
Conductors
Conductors will either be run as Romex internally or through an approved conduit externally. If
an external disconnect is required in your jurisdiction, include this location on the roof layout.
Label all equipment and conduit sizes on the roof layout.
1”

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Other Electrical Equipment
Include junction boxes and disconnects on your roof layout as needed. The conduit will connect
all of this equipment in the same sequence as your electric diagram. For this reason it may be
helpful to finalize the electrical line diagram before finalizing equipment placement on the roof
layout.

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Section III. Creating an Electrical Diagram
It is important to understand the electrical design principles specific to Westinghouse Solar technology
before you begin your electric line diagram. Sample designs for 15 panels (or fewer), 30 panels and 45
panels are provided in an Appendix. Below are some important concepts to consider as you create
your roof layout and electric line diagrams:
1. Westinghouse Solar AC Electrical Requirements
A. Westinghouse Solar AC Panels may be arranged in branch circuits of up to 15 when working
with 240V single phase electrical systems. Each branch circuit will need to be isolated using
NEC compliant circuit protection
B. When Westinghouse Solar AC panels are arranged on a roof layout, they are wired in parallel,
and invert DC power on a per panel basis. For this reason, panels can be placed on roofs of
varying pitches, orientations, and shading scenarios. Their performance will not be hindered
by adjacent panels in the same branch circuit.
C. Westinghouse Solar AC branch circuits require three proprietary components to complete a
multi row branch circuit. An AC branch circuit is ended with an “end cap,” which is a plastic
fitting that protects the last inverter in a circuit from moisture and exterior elements. Because
the wiring harnesses come built into the inverters at a preset length, a 6' extension cable is
necessary to wire branch circuits in the north /south direction, and also to route the inverters
past obstructions (such as a vent pipe). Finally, Westinghouse Solar AC circuits are completed
with a “Pigtail” connector; the Pigtail transitions the inverter's conductors from the UV rated
insulation to four color-coded conductors that can be utilized inside a junction box on the
edge of an array. Each Westinghouse Solar AC kit includes one Pigtail and one end cap.
D. Inverters mounted on Westinghouse Solar AC panels work most conveniently when the wiring
harnesses are aimed towards the junction box, or final destination for a circuit on a rooftop.
By carefully planning the direction and orientation of Westinghouse Solar AC Panels, your wire
management will be simplified and system will be installed with fewer extra components.
E. Westinghouse Solar AC inverters are attached to the panel frame using an UL-approved
bonding method. These attachments utilize thread-forming bolts in addition to star washers
to ensure a solid and redundant bonding path between the frame and inverter.

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F. Drafting the Electrical Line Diagram.
Figure 11 - Inverter components in a two row array
2. Single line diagram preparation
Prior to drafting the diagram it is necessary to identify the size and capacity of the existing
electrical system components. You will also need to research the additional equipment you may
need to include based on special local utility and building department requirements.
Electrical Site Survey List:
A. Main Panel bus rating- This information can be found inside the electrical service door
on a sticker label, common residential bus ratings are 100A, 125A, and 200A.
B. Main Disconnect Rating-The main disconnect rating is printed directly on the main
breaker. It is common for the main breaker's rating to match that of the main panel
bus. The main breaker should not exceed the rating of the main panel.
C. Available breaker space-The most straightforward method to back feed a residential
grid-tied electrical service is by utilizing a double pole breaker to interconnect your
circuit (up to 15 panels) or circuits (if more than 15 panels) to the main panel. Survey
how many breaker spaces are available; a double pole breaker will require approx. two
inches of space in your average residential service panel.
D. Grounding-Check that a ground rod is present, serving as a grounding electrode to the
main electrical service. If you cannot identify a grounding electrode, per section 250 of
the NEC, a new one will need to be installed to assure a safe grounding path for your
solar equipment. The grounding electrode, new or existing needs to be included in your
electrical line Diagram.
E. Wiring Location-Is there a clear pathway through crawl spaces and attics to route your
Westinghouse Solar AC system conductors? Will the wire run be external to the
structure? How long is the wire run? This information will be a factor in sizing your

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conductors and what types of materials you will need to use in reference to the U.S.
NEC, if applicable.
3. Electrical Line Diagram
The sample Electrical Line Drawings in the appendix are provided as a starting point. Three
drawings (15 panels, 30 panels and 40 panels) are provided that include multiples of 15
Westinghouse Solar AC Panels in branch circuits. Use the sample drawings as a template, and
identify the exact number of panels in your system. Completing your electrical line diagram circuit
can be as simple as labeling the equipment rating and defining whether you are wiring the system
with Romex or using a conduit with individual conductors. The following details should be
provided:
•Type of utility meter, voltage rating, and phase (bi-directional utility meter, 240
VAC, 1 Phase).
•Main panel manufacturer, main panel bus rating, main disconnect rating (Square D,
200 A rated main panel, 200 A main disconnect).
•The grounding electrode and an appropriately sized conductor grounding the main
panel.
•The voltage, number of poles, and circuit protection rating of the breaker used to
interconnect with the main service, (240 V, double pole, 30 amp breaker).
Conductor sizing, overcurrent protection, load centers, disconnect switches, and other equipment
must be sized according to the National Electrical Code, in addition to any special requirements of
the local permit jurisdiction. Special considerations for solar include, but are not limited to, the
following:
•Conductors and connectors used on the roof must be rated for 90 degrees C
•Conductors on the roof should have their ampacity de-rated for a temperature of at
least 70 degrees C.
•Voltage drop between the array and the main panel should not exceed 1.5%.
•The sum of the overcurrent protection of all power sources (line + PV) feeding a bus
bar or conductor must not exceed 120% of the current rating of that equipment.
•Warning labels as required by your local jurisdiction.
4. Grounding
Rows of Westinghouse Solar AC panels spliced in the East-West direction are bonded by the same
stainless steel splices that connect the panels structurally. The North-South bracket provides
grounding when used with grounding washers for columns of Westinghouse Solar panels.
Westinghouse Solar splices are a UL listed grounding component. At the end of each row in the
east-west orientation there is a factory designated bonding location for attaching a lug.