New Solar Fire Regs Discussion Heats Up

Several people involved in the creation of the new fire regulations respond to this article.

We are writing to address several statements in the recent Solar Power World article titled “New Class ‘A’ Fire Regulations Closer Than You Think,” published Aug. 19, 2014, that we believe are inaccurate.

In the article, the author states that “racking systems from SolarDock and solar panels from Motech — are literally the only way to be compliant” with Class A Fire Regulations being enforced by the state of California. This statement is incorrect. There are already several solar racking systems that have been tested and listed for the “PV System Fire Class rating” requirements of UL1703 including Zep, Sunlink, Sunrun South, Quick Mount PV and PanelClaw. Numerous additional racking systems are in the process of testing for system fire classification, and many more racking systems are anticipated being added to the list of class A fire rated system before California starts mandates PV systems have a UL “PV System Fire Class rating” in January 2015.

While it is possible to test a specific make/model of PV module with a specific make/model of racking system, it is important to note that UL1703 “PV System Fire Class rating” does not have to be unique to a specific make/model of PV module. Rather the more likely scenario is the testing a specific make/model of racking system with a representative PV module that has been categorized to a particular “fire classification type”. This means a racking manufacturer can test their system with a PV module that has been “typed” for fire classification. If the racking system passes with a “Class A” fire rating with a type 1 module, their customers can use any type 1 module and be considered class A fire rated as a system.

Just to clarify: Specific modules can be tested with specific racking systems (and appropriate roof material) to obtain a PV System Fire Class rating under UL 1703/2703. If this method is used, only that specific combination of modules and racks will maintain the PV System Fire Class rating. However, most mounting system manufacturers will likely test with fire “typed” modules, which enables them to substitute any other module of the same fire “type” to maintain their “System Fire Class” rating. This improves the options available to installers and system owners. As of this writing, there are 15 “fire classification types” for PV modules, however, the significant majority of PV modules used in residential and commercial PV systems will be type 1 and type 2. If the listed racking system has been tested to “class A” fire rating with both type 1 and type 2 modules, the installer can use any type 1 or type 2 module and still maintain the “class A” PV System Fire Class rating.

One additional point that should be made: There is more than just Class A fire rating. There are many modules that will only pass Class B or C fire rating when considering spread of flame tests especially for module Types 4-9.  The system testing will still be with a Class A roofing material, so the pass/fail distances are the same, but the resulting certification will on be Class B or C system fire rating. This will satisfy the state of California requirement that mandates the PV system match the required fire rating of the roof as the majority of areas in California only require that roofs be class B or class C. Only a minority of jurisdictions require that roofs and PV arrays be Class A. Areas with class A fire rating requirements are those that are vulnerable to wild land urban interface fires.

Since the new fire classification requirements will be implemented soon, it is important we clear the confusion on how the standard works and how the system fire classification testing is performed. To that end, we would like to clarify the following items from that same article…

• The article claims that the UL2703 standard has testing for mechanical loading that will rate systems A through C depending on how much load it can handle. This is incorrect. There is no class rating system for loading, rather, the racking manufacturer will test their system for a specific load capacity (ex. 30 psf) and that load level will be referenced in the listing to allow building departments to insure the racking/module/grounding system will be able to withstand regional requirements for structural requirements (wind, snow, seismic forces).

• The spread of flame testing for low slope systems requires testing to a roof material that has a “Baseline” spread of flame of 48″, not the stated 44.2″

• For most racking systems, there are 6 tests required for spread of flame not 3 as stated in the article. For most low slope racking systems, there are 2 tests upslope, 2 test downslope, and 2 tests from the side (as long as both sides are geometrically symmetrical) The only exception is where one of those directions is proven to be the worst case scenario, in which case the other 2 directions would only require a single test resulting in 4 tests total.

• It is also important to understand that for low slope PV systems, there is no burning brand test modules installed in racking systems. The burning brand test is performed on the surface of the module alone, independent of any racking system. Additionally there is no need to test a low slope racking system for a burning brand on the interstitial space (between the module and the roof).

The 1703 and 2703 STPs will soon be working to develop new training materials to help manufacturers, installers, and building departments understand these rapidly evolving standards and fire testing procedures. As part of the outreach effort, we will be writing an article for an  upcoming issue of SPW to explain how the new UL2703 standard works as the vote for ANSI accreditation is rapidly approaching.