Fire Safety in PV Systems: Understanding Fire Rating and Prevention

Photovoltaic (PV) systems are increasingly popular as a clean energy source for homes, businesses, and communities. These systems convert sunlight into electricity, powering various establishments.

However, like any electrical system, PV systems can pose fire risks if not installed correctly.

Therefore, understanding the fire safety considerations related to PV systems is essential for their safe operation.

Importance of Fire Safety in PV Systems

PV systems present unique fire safety challenges that must be addressed in order for them to operate safely.

PV systems' high voltage and direct current nature can generate electrical arcs and sparks, which can ignite nearby materials.

Furthermore, if PV modules are not properly installed and maintained, the heat generated by them can cause fires.

As a result, fire safety considerations must be considered during the design, installation, and operation of PV systems.

Fire Rating Standards

Several industry standards exist to provide guidance on the fire rating of PV systems. These standards include:

UL 1703

UL 1703 is a standard developed by Underwriters Laboratories that outlines the fire rating requirements for PV modules.

This standard covers various aspects related to fire safety, including:

• Flammability of the module: UL 1703 sets requirements for the flammability characteristics of PV module materials, ensuring that they do not contribute significantly to the spread of fire.
• Ignition resistance of the module: The standard specifies tests to determine the ignition resistance of PV modules, ensuring that they are not easily ignited by external sources of heat or flame.
• Spread of flame on the module: UL 1703 includes testing procedures to evaluate the spread of flame on the surface of PV modules when exposed to fire.

By adhering to UL 1703, manufacturers can help ensure that their PV modules are designed and built with fire safety in mind, reducing the risk of fire-related incidents in solar energy systems.

This compliance is crucial for installers and end-users to have confidence in the quality and safety of photovoltaic modules used in solar installations.

IEC 61730

IEC 61730, a standard created by the International Electrotechnical Commission, defines the fire rating requirements for PV modules.

This standard aims to ensure the safety and reliability of photovoltaic modules across diverse applications and environmental conditions.

IEC 61730 consists of two parts:

IEC 61730-1: Construction Requirements: IEC 61730-1 addresses the general requirements for materials, design, and construction of PV modules. It encompasses specifications for factors such as mechanical load, impact resistance, temperature, and humidity.

IEC 61730-2: Testing Requirements: IEC 61730-2 details the testing procedures for PV modules, ensuring their compliance with the requirements set forth in IEC 61730-1. This includes tests for electrical insulation, mechanical load, thermal cycling, and more.

The IEC 61730 standard plays a crucial role in guaranteeing that PV modules are safe, reliable, and can endure various environmental conditions without posing risks of fire or other hazards.

Adherence to this standard is vital for manufacturers, installers, and end-users to trust the quality and safety of photovoltaic modules used in solar energy systems.

NFPA 70, National Electric Code

The National Electric Code, or NFPA 70, offers guidelines for electrical system installations, including PV systems. This code encompasses requirements for PV system installation and addresses fire safety considerations.

PV Solar Protection Rating Grades

PV solar protection rating grades, also known as fire rating grades, indicate the level of fire resistance for a PV system.

Standards such as UL 1703 and IEC 61730 determine these grades by assessing flammability, ignition resistance, and flame spread on PV modules. PV systems typically have three fire rating grades: Class A, Class B, and Class C.

Class A

Class A is the creme de la creme of PV solar protection and fire resistance ratings. These modules have passed the most stringent fire tests, including the ASTM E84 and UL 790 tests, and are the least likely to ignite or spread flames.

The ASTM E84 test checks out the surface burning properties of building materials, whereas the UL 790 test focuses on the fire resistance of roofing materials.

When faced with a fire, PV modules with a Class A rating have been put to the test to resist the spread of flames and the generation of smoke.

To receive a Class A rating, PV modules must have a flame spread rating of 0-25 and a smoke development rating of 0-450.

The flame spread rating measures the speed at which flames travel across the module's surface. Meanwhile, the smoke development rating checks out the amount of smoke produced.

Class A modules are ideal for high-risk fire areas or places where maximum fire protection is a must. They are commonly used in commercial, industrial, and residential applications where local building codes mandate a high level of fire protection.

The Class A rating guarantees the highest level of fire protection for PV systems. It's a crucial consideration for ensuring the safety and reliability of these systems.

Class B

When it comes to PV solar protection, the Class B rating sits in the middle, providing a moderate level of fire resistance in comparison to Class A modules.

Although not subject to the same extensive fire tests as Class A modules, modules with Class B ratings still offer decent fire protection standards.

To achieve a Class B rating, the modules need to pass a flame spread rating range of 26-75 and a smoke development rating of 0-450.

Class B modules are suitable for areas with moderate fire hazards, commonly used for residential applications. They don't offer the same level of fire resistance as Class A modules, so you need to consider the installation location's specific fire hazards and appropriate fire ratings.

Overall, the Class B rating provides moderate fire protection for PV systems and is crucial for ensuring their safety and reliability.

Class C

When it comes to PV solar protection, modules rated Class C offers the least level of fire resistance, making them the most prone to ignite or spread flames.

Overall, Class C modules undergo less rigorous fire tests than Class A and B modules.

To achieve a Class C rating, they must pass a flame spread rating range of 76-200 and a smoke development rating of 0-450, which measures the speed at which flames travel across the module’s surface and the amount of smoke produced.

Class C modules are typically utilized in low-fire hazard areas, where local building codes don't need high-level fire protection, commonly found in residential applications.

It's worth noting that in the event of a fire, Class C modules could ignite or spread flames quickly since they offer the least level of fire protection.

Therefore, you must assess the location's specific fire hazards and opt for the appropriate fire rating for the intended use.

In conclusion, the Class C rating offers the lowest level of fire protection for PV systems, which is a significant aspect to consider in low-fire hazard areas to ensure their safety and reliability.

Which fire-level-rated product would you need?

The fire rating required for your PV system will depend on several factors, including:

Location

If you plan on installing a PV system in a wildfire-prone area, it may need a Class A fire rating due to the heightened risk of fires in such regions.

Wildfires can quickly spread and easily ignite PV systems, underscoring the need for high fire resistance.

Local building codes may require PV systems with Class A fire ratings for installation in these areas in certain cases.

In regions with high temperatures or extreme weather conditions like deserts, a PV system may require a higher fire rating due to the increased risk of fires resulting from high temperatures or lightning strikes.

In these instances, a PV system with a Class A fire rating may be the most effective at preventing the spread of flames.

Building codes

In order to meet the local building codes for fire safety, PV systems must be installed with specific fire ratings such as Class A or Class B.

This is especially important in areas where there are high-risk fires like California which requires all PV modules installed in certain areas to have a Class A rating.

To ensure that these requirements are met, it is necessary to install additional measures such as fire barriers and/or a fire-resistant mounting system.

The National Fire Protection Association (NFPA) has guidelines for the installation of these types of systems which will help protect against flames spreading if a potential incident were to occur.

It’s essential that when installing any type of photovoltaic system you consider the local building codes and follow appropriate regulations regarding their construction and installation so they can provide maximum protection from fires while still providing reliable energy generation capabilities throughout its life cycle.

Fire hazards

When installing a PV system near potential ignition sources, such as gas pipelines or propane tanks, a higher fire rating is critical to prevent flames from spreading to the PV system.

In these cases, a PV system with a Class A fire rating would be ideal because it provides the highest level of fire resistance.

Similarly, PV systems installed in areas with extreme weather conditions, such as high winds or high temperatures, may require a higher fire rating to ensure the system can withstand these challenges.

For example, a PV system in a hurricane-prone area may require a higher fire rating to prevent flame spread during high winds.

Choosing the appropriate fire rating for the PV system will help ensure its safety and reliability under various conditions by carefully considering the specific environmental factors and potential hazards of the installation location.

Type of building

When installing a PV system, it is critical to consider the type of building on which it will be installed. This is especially important when assessing fire risk and protecting building occupants and critical infrastructure.

For example, if you're installing a PV system on a high-rise building or a hospital, you'll almost certainly need a higher fire rating to keep flames from spreading vertically.

A Class A fire rating is frequently recommended in these situations because it provides the highest level of fire resistance, minimizing damage and limiting the spread of flames.

However, depending on the fire risk in the surrounding area, installing a PV system on a single-story or low-rise residential building may not necessitate such a high fire rating. In such cases, a fire rating of Class B or Class C may suffice.

Insurance requirements

Insurance providers often require a specific fire rating for PV systems to ensure proper coverage in the event of a fire.

The required fire rating may vary based on the building's location or type and the associated risks.

In some instances, insurance companies might mandate a higher fire rating for PV systems to reduce fire risk and minimize potential damage.

Besides fire ratings, providers may also require additional fire prevention measures, such as installing fire alarms, to increase safety and mitigate losses in case of a fire.

When considering the installation of a PV system, it's important to review your insurance policy's specific requirements to ensure your system has the appropriate fire rating and protection.

Investing in a higher fire rating and additional fire safety measures can offer peace of mind and safeguard your investment from potential fire-related damages.