In this lesson, we will discuss topics starting from building, fire, mechanical, and electrical codes and then we will finish with the inspection requirements for PV systems. Whether you are a PV designer or installer, it is important to familiarize yourself with various codes and regulations to efficiently work on PV systems at different scales. We will also see that codes apply to all PV scales starting from small residential systems to large scale PV plants.

Learning Outcomes

At the successful completion of this lesson, students should be able to:

• Identify relevant electrical and building codes that govern PV systems at various locations.
• Discuss standards and design qualification testing that help ensure the safety and reliability of PV system components such as UL, local, and national electrical code NEC articles.
• Identify important warning signs and equipment labeling, notes, and other safety requirements associated with PV systems.
• List design guidelines, drawing, and documentation requirements and methods.

In previous lessons, we briefly discussed applicable codes that apply to PV components such as Underwriters Laboratory (UL) and IEEE, which are the manufacturer's responsibility before they sell the final product.

In this lesson, we will elaborate more into different standards that are beyond the standards specific to PV components. If we zoom out a little to view the overall PV system, we see that there are various regulations and standards that need to be met before installing a PV system in the U.S. PV market.

There is a collaborative effort funded by international and local agencies (such as the U.S. Department of Energy) that dedicates experts to transforming solar markets by developing building codes, fire codes, electrical codes, utility interconnection procedures, product standards, reliability, and safety. In addition, a part of their overall strategy is to reduce barriers to the adoption of solar technologies and to stimulate growth in different marketplaces. There are various codes, standards and regulatory requirements applicable to PV installations. We will not address the content of most of these codes. However, we will help you become familiar with these organizations and main codes and standards that are most relevant to this course.

It is important to mention that most of the codes and standards, listed in this lesson, have been adopted in various states. However, some states are still working on adopting them while others prefer to have a local city code. It is wise to consult with the city where the PV system will be installed to assure complying with the right local codes.

Building codes

The International Code Council (ICC)

ICC is an international organization that develops a set of comprehensive international model construction codes focused on building safety and fire prevention. Many ICC Codes (AKA I-Codes) have sections relevant to PV installations, including:

The International Building Code (IBC):

IBC covers all types of buildings except the detached one and two family dwellings and townhouses that don’t exceed three stories in height. The IBC includes requirements for the fire class rating of PV systems and it contains wind load calculations (as we briefly discussed in Lesson 5 when we talked about BOS structural calculations).

International Residential Code (IRC):

IRC establishes minimum regulations for one and two family dwellings and townhouses up to three stories in height that are not addressed in IBC. It brings together all building, plumbing, mechanical, fuel gas, and energy and electrical provisions, which include PV systems for one and two family residences.

International Fire Code (IFC):

IFC includes regulations governing the safeguarding of life and property from all types of fire and explosions hazards, which include PV systems. IFC addresses topics include general precautions against fire, fire department access, and fire safety requirements for new and existing buildings and premises. The IFC includes requirements for PV labeling, access and spacing, and the location of DC connectors and other. It is considered the most relevant to rooftop PV installations.

International Green Construction Code (IGCC):

IGCC is a model code focused on new and existing commercial buildings. It addresses green building design and performance to establish minimum green requirements for buildings. This code is related to the grading of buildings rather than safety regulations, as the previous ones do.

International Code Council Evaluation Services (ICC-ES)

ICC-ES involves technical evaluations of building products, components, methods, and materials. The evaluation process culminates with the issuance of technical reports that directly address the issue of code compliance and is useful to regulatory agencies and building-product manufacturers.

Mechanical Codes

IAPMO Codes and Standards

The International Association of Plumbing and Mechanical Officials (IAPMO) works with government and industry to implement comprehensive plumbing and mechanical systems all around the world. There are many IAPMO codes and standards that pertain to PV installations.

Electrical Codes

International Electrotechnical Commission (IEC)

The International Electrotechnical Commission (IEC) [6] publishes international standards for all electrical, electronic and related technologies. The United States formed an IEC National Committee (USNC) to oversee the country's participation in IEC activities, and that is governed by the American National Standards Institute (ANSI). The IEC promotes international cooperation on all questions of standardization and the verification of complying to standards and often serves as the basis for national standardization and as a reference when drafting international tenders and contracts. The IEC standards include all electrotechnologies, which also includes PV systems for energy production and distribution.

Institute of Electrical and Electronics Engineers (IEEE)

The Institute for Electrical and Electronics Engineering (IEEE) Standards Association [7] publishes hundreds of industry-driven consensus standards in a broad range of technologies and applications, including photovoltaic (PV) systems and the integration with the utility grid. The IEEE global outreach drives the functionality, capabilities, and interoperability of a wide range of products and services.

National Fire Protection Association

The NPFA 70: National Electrical Code (NEC) developed by National Fire Protection Association (NFPA) [8] issues the National Electrical Code® (NEC), the Uniform Fire Code, and other codes. The NEC is updated and published every three years and is considered to be the most comprehensive electrical safety installation requirements document in the world. Published by the National Fire Protection Association, the NEC is over 115 years old with 50+ editions and over 800 pages and articles. The first PV related article was added to the NEC in 1984 (Article 690) and is legislated into law by all states and most major cities in the US and some international places.

There are many articles of the NEC referenced in Article 690 that apply to PV installations. Whenever the requirements of Article 690 and other articles differ, the requirements of Article 690 apply.

Testing and Material Related Codes

ASTM International

ASTM International [10], also known as the American Society for Testing and Materials (ASTM), is an organization that develops international standards with a goal to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence. The ASTM has tens of standards that pertain to PV technology.

Underwriters Laboratories

As discussed earlier, Underwriters Laboratory (UL) [11] develops safety standards including standards for PV related products. UL's standards are essential to helping ensure public safety and confidence, reduce costs, improve quality, and market products and services. Most products in the U.S. undergo UL testing and listing credentials.

As we can see, finding the solar and PV related local and international codes can be a tedious task due to the variety of engineering disciplines involved in solar systems. Therefore, as a combined effort, ICC provisions coordinated and developed a model code to bring together all solar energy provisions found throughout the 2015 ICC (or I-Codes) that pertain to solar thermal and PV energy systems. As a result, ICC published the International Solar Energy Provisions (ISEP) that simplify the implementation of I-Codes in the jurisdiction where solar and PV systems are to be installed. Furthermore, since most PV system include electrical components and systems, NFPA 70 or NEC related articles are integrated into the ISEP 2015.

The ISEP is organized in chapters with related topics and it differentiates between commercial and residential applications. You can also notice cross references between I-Codes within the ISEP chapters. In additions, ISEP references other standards across the chapters, such as ASTM, IBC, IFC, IRC, NFPA 70 (NEC), and UL.

Let's look at an example:

If you are designing a PV system in a jurisdiction that approves international (I-codes), the ISEP 2015 will become handy to find related PV code sections such as LBC, IFC, and IRC code sections. Designers need to pay attention to the system installation type considerations to comply with these codes. For example, below we have two scenarios of PV systems:

We saw in the previous example that the ISEP adopted IFC 605 for electrical equipment, warning and hazards. In addition, the National Fire Protection Association NFPA 70 (NEC 690) and International Fire Code (IFC 605) both require that marking is needed to provide emergency responders with appropriate warning and guidance with respect to isolating the solar PV system. This helps in identifying energized electrical lines that connect the solar modules to the inverter to prevent cutting these wires when venting for smoke removal.

Materials used for marking should be able to withstand extreme weather conditions. Different materials can be used for warning signs. Vinyl signs need to meet UL requirements, while plastic and metal engraved signs do not need to meet any UL standards.

In rare cases, fire can be caused by solar modules. An example of this occurred in a residential application in New Rochelle, NY. Complying to marking and labeling code requirements can help firefighters find the energized circuits in the property and disconnect the power to safely work on the property.

Labeling is required at certain locations in the electrical PV system, such as:

1. PV modules labels: usually provided by manufacturers and has main electrical parameters such as current, voltage, and power.
2. Disconnect labels: Either AC or DC sides, all disconnects need to be labels and visible. Labels must include maximum current and voltage. For PV systems, labels need to list the operating voltage as well. In addition, a warning sign needs to be placed on disconnect where terminals may remain energized in the open position.
3. Point of connection labels: This is specific to interactive systems. A label needs to be located at the point of interconnection and must identify the interconnection utility service.
4. Other energy source labels: For any other energy source such as batteries, labels must indicate the maximum operating voltage and polarity of a DC system.
5. Grounding labels: Whether the system is grounded or ungrounded, labels must identify the ground-fault current and a warning signage stating the grounded system may be ungrounded and energized.

As mentioned in the overview of this lesson, in addition to the aforementioned codes, local jurisdictions and municipalities can amend and change some codes to some extent. Local municipalities have final jurisdiction and authority for projects, so communicating with your Authority Having Jurisdiction (AHJ) and understanding permit requirements is going to be an important element of your job as a PV designer and installer.

Permitting and inspection

For most PV systems, permits are required from the building department, electrical department and, perhaps, fire department in some cases. The permits are important to ensure code compliance for a functional PV system.

After the permits are granted, installers and integrators can start the installation process. Upon the completion, an inspection should be scheduled to ensure complying with the design and installation standards. Inspection is usually done for the structural and electrical parts of the systems. Integrators will need to verify with their AHJ.

Design Requirements

Any solar design needs to meet certain requirements to function properly. The city, utility, or AHJ might request a design package that complies with national and local standards. This may include:

1. The conceptual package showing the overhead of the location of the PV system and the utility interconnection point. 
2. The one-line and three-line electrical drawings showing how the electrical connection between components is done and check electrical code compliance such as NEC.
3. The mechanical and structural design showing the load on the PV array and the holding structure.
4. Warning and signage that labels main parts of the PV system and provide guidance to utility personnel.
5. Bill of material showing quantity and type of components used for the project.
6. Official stamps by Professional Engineers (PE) for the electrical, mechanical, or structural documents (if needed).
7. The specification datasheets for the main PV components.

Lesson 7 Discussion

Activity	Details
Assignment	Post original entry: In this lesson, we covered code applicable to PV systems. Based on previous discussions, we learned that PV systems classification can include more specific market sector, such as:   Solar installation for rural off-grid application Residential rooftop for grid-tied application Utility Scale PV installations Shared solar for communities In this lesson, we ask our solar professionals to discuss the importance of one PV code. In other words, what are the consequences of not complying with such codes? You may discuss how applicable codes might vary for different installation types. Support your post with links to actual PV installation examples. Discuss specific code considerations for one of the options. Support your discussion with facts (you may research the same solar installation example you selected for the Lesson 1 and Lesson 6 Discussions. (Hint: the fire hazard referred to in the lesson is an example of the labeling and code compliance for residential buildings. Also use ISEP to compare different PV system types and how codes might vary!)   Post comments: Respond to two different opinions of others' posts. (For example, if you choose Option 1, you need to respond to one post for Option 2 and another post for Option 3 or 4.)
Requirements, Submission Instructions, and Grading	For more detailed instructions about the discussion component of this course, including how you will be graded, please visit the Discussion Activity [13] page.

Let’s go back to the scenarios from the beginning of this lesson where you need to prepare the required documents for permitting to get approval on your PV system design before you start the installation process. By now, you should understand that PV installations involve different building, fire, mechanical, and electrical codes and standards. Furthermore, you learned that your local city may adopt the national and international codes with slight variation. You need to consult with your local AHJ to insure you are complying with the requirements of the location.

In the next lesson, we will zoom into the NEC code and discuss the various articles that are in concern to us as PV designers to insure a safe and functional PV system.