CODE CORNER: The International Fire Code and PV Systems

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Labled PV conduit
All raceways containing DC conductors from the PV system must be installed in specific locations and labeled with specific language as defined by the IFC and NEC.
Rooftop PV system
This rooftop installation minimizes trip hazards by routing the raceway adjacent to the array and leaving the required space near the roof for ventilation access.
Rooftop pathways
Gable roofs require two 3-foot-wide pathways from eave to ridge, as shown, in addition to 3 feet of space between the ridge and top of the array for smoke ventilation.
Labled PV conduit
Rooftop PV system
Rooftop pathways

In HP164, “Code Corner” discussed Section 690.12—new National Electrical Code (NEC) requirements for controlling PV conductors on or in buildings. This time we tackle a complementary section—605.11—in the 2012 International Fire Code (IFC). The 2012 IFC was adopted by a number of jurisdictions and has been getting a lot of attention in the PV industry, since it addresses labeling requirements, equipment locations, and clearances around rooftop PV equipment. Detached, nonhabitable Group U structures (such as agricultural buildings, barns, carports, garages, parking structures, and pergolas) are exempt from 605.11 requirements.

Examining the overall intent of the IFC can help you understand the requirements framework. The intent, according to Article [A] 101.3, is “to establish the minimum requirements consistent with nationally recognized good practice for providing a reasonable level of life safety and property protection from the hazards of fire, explosion or dangerous conditions in new and existing buildings, structures and premises, and to provide safety to firefighters and emergency responders during emergency operations.” Careful consideration needs to be made for the layout of rooftop systems in advance of the permitting process, since rearranging modules after the design is completed can be a difficult and costly endeavor.

Section 605.11.1 governs marking electrical assemblies containing DC conductors in both interior and exterior locations to help emergency personnel quickly identify (and shut down) energized sources, which could pose a shock hazard. These requirements mirror the requirements set in Section 690.31(G) of the 2014 NEC. All raceways, enclosures, junction boxes, cable assemblies, combiners, and disconnects need to be clearly labeled to indicate the presence of PV conductors. The labels shall have “WARNING: PHOTOVOLTAIC POWER SOURCE” in all-white, capital letters, a minimum of 3/8 inch tall, on a red background. These labels must be reflective and weather-resistant.

IFC mandates the marking locations on all interior and exterior raceways, enclosures, and cable assemblies. This labeling has the added benefit of helping ensure the conductors won’t be confused with those from a different electrical system, like an AC circuit that could be used to run a new load. This section’s labeling must be applied:

  • Every 10 feet
  • Within 1 foot of turns or bends
  • Within 1 foot of penetrations through roofs/ceilings, walls, or other barriers

Section 605.11.2 specifies the locations for DC conductors—to minimize trip hazards for firefighters and not obstruct potential areas for ventilation access. The IFC accomplishes this by requiring PV circuit raceways be run as close as possible to the roof’s ridge, hip, or valley. Raceway transitions from a hip or valley should take the shortest/most direct path to an exterior wall. If combiners or junction boxes are used for multiple subarrays, they should be installed and connected in a manner that minimizes raceways on any pathways and that keeps the raceways as short as possible. As with the NEC, metallic conduit or raceways are required for DC circuits located inside buildings.

The next section, 605.11.3 Access and Pathways, can be the most challenging section of 605.11 to meet, although local AHJs may allow exceptions. Section 605.11.3.2.4 governs roof access for smoke ventilation, and is applicable to all rooftop installations, regardless of roof type. To meet this section’s requirements, modules must be installed at least 3 feet below a roof’s ridge. Since this is not a pathway requirement, the space doesn’t have to be clear of obstructions.

The array cannot block access to the roof for firefighters attempting to gain access from the ground. Available roof access points must be able to support a firefighter’s load and not be located directly in front of windows and doors. For the pathway requirements, the IFC establishes rules for three specific roof layouts: hip, gable, and hip-and-valley. These rules apply to roof slopes greater than 2:12 pitch and require the pathways to be located over structurally supported areas that can support the live load of a firefighter.

For hip roof layouts, 605.11.3.2.1 requires a single 3-foot-wide, clear pathway from ridge to eave on each slope where modules are located. Buildings with a single roof ridge (aka gable) are covered under 605.11.3.2.2, which requires two 3-foot-wide, clear pathways from ridge to eave on each slope where modules are installed. The exact location for each pathway is not defined; typically, the most convenient location will be on outer edges of the roof as long as they are structurally supported.

Pathway requirements for buildings with hips and valleys are detailed in 605.11.3.2.3. These complex roof shapes can make meeting the Code difficult. They must have at least one 3-foot-wide, clear pathway from ridge to eave on the slope that has modules, regardless of what is on the other side of the roof. If there are modules on both sides of the hip or valley, then a minimum 18-inch pathway needs to be provided on both sides of the hip or valley (to create a 3-foot-wide pathway). If the other side of the hip or valley is without modules, the PV array can go all the way to the hip or valley.

Premade IFC/NEC labels can be found at:

Comments (7)

David Bangley_2's picture

A solar array has a probability of operating 100% of the days it is on a roof, while a fire event requiring roof ventilation is likely to never happen. In a fire event, who cares if a ladder damages a solar panel? It is insured. A high voltage DC system presents risks, but I would be perfectly willing to drop a fire ax through a panel on a microinverter system. I already have a code required kill switch with a big red sign for the firefighters. How is the remaining 36 volts a problem? Are high voltage DC arrays going to be installed on homes 5 years from now? I doubt it. My concern is this: code writers limit innovation and efficiency by carving out restrictions based on unlikely scenarios, and technologies that are already being phased out.

Ryan Mayfield_2's picture

The pathway requirements are there for both ventilation and roof access. In the case of the ladder hooking on the roof, the firefighters aren’t concerned with damaging the modules, they are concerned with getting on the roof and even more important, getting off, safely. The rapid shutdown switch is great for the firefighters but it doesn’t solve their roof access issues. And expecting fire fighters to drop axes through modules isn’t a working solution regardless of the wiring configuration and power electronics selection IMO.

I agree high voltage dc arrays are likely phasing out, specifically on residential applications. But I wouldn’t go so far as to say they absolutely won’t exist in five years. One of the tough issues here is Codes are written a full three years prior to their release. In an industry such as ours, that is a lifetime away in terms of available equipment. The Code writers can’t keep up to technology, they are constantly playing catch-up.

The requirements are difficult to work within I know, I face it every day. At the same time, the last thing we need is the insurance industry getting the idea that any roof with solar on it eliminates firefighter from accessing the building and fighting fires.

As one of the early solar pioneers I got to work under was fond of saying, if you don’t like the direction the ship is taking, get in the captain’s seat and steer it yourself. Code making panels are made up of industry volunteers giving input and helping steer the ship. We need all the input we can get to help our industry.

David Bangley_2's picture

"Section 605.11.3.2.4... modules must be installed at least 3 feet below a roof’s ridge." As I look through the magazine, most of the rooftop PV photos in this issue- including the cover- violate this new rule. Why not count the empty north roof of a solar home as a clear area for firefighters to work? For servicing, wind resistance, and fire safety it makes sense to leave space on both sides of an array, but the restriction at the top is going to hurt system designers and seems arbitrary when the north side of the roof is unobstructed. South facing roof area is valuable, and should be treated as such.

Mark@exactsolar.com's picture

I talked with a local fire captain about this while planning for an upcoming installation. He said that they often use ladders that hook over the ridge and that they want to be sure the hooks don't hit a panel.

Mark Bortman
Exact Solar

Ryan Mayfield_2's picture

David, a few years ago (prior to IFC 2012) there was a specialty code written for solar installations in Oregon. A major portion of that Code was fire access, similar to the requirements I talked about in this article. During round-table discussions, the same request (use the north side) was presented. The firefighter's rebuttal was that the need for cut-out areas can't be predicted and cutting holes on the wrong portion of the roof during a fire can actually make the fire worse. The intention here is to give them the ability to make the cutouts on either side, based on the exact needs.

Bill Loesch_2's picture

Ryan, David also asked the question why so many of the photos shown [in both of your bi-monthly magazines] still today, do not comply with the roof setback requirements that are useful/required for firefighters? Thanks.

Ryan Mayfield_2's picture

I can't speak for all (or even most) photos, especially since I am a contributing author, not a staff member. But I'm willing to address the point. There are a number of photos that likely don't adhere to the various Fire Code requirements as set in the IFC and local jurisdictions but part of the problem is the varying degree of implementation there is across the country and the date in which the Codes are adopted. So the photos used may (or may not) be in full compliance for their specific locations at the time they were installed. And then there are the locations where variances have been granted or where there are difference between IFC an local requirements. To quote Matt Paiss of the San Jose, CA fire department from a recent SolarPro article:

"Each state or jurisdiction adopts the fire code of choice according to its own procedures and updates code editions according to its own calendar. According to a database maintained by the ICC, as of March 2014, approximately 23 states have adopted the IFC at the state level. Ten of these states—including California—have already adopted IFC 2012,which includes the new requirements for PV systems; seven states are still enforcing the 2009 edition; four states have yet to update from IFC 2006; and two states are still enforcing the 2003 edition. Meanwhile, another 19 states have adopted some edition of NFPA 1.”

The exact numbers very well may have changed since he made this quote, but that just illustrates the difficulty of representing all systems as IFC complaint even more. I'm not trying to represent that all of the photos shown in either magazine are in full compliance or find an excuse for those that aren't, just point out that without complete knowledge on the entire system, it is difficult for us as authors and editors to know if there are issues in this area.

I think as time passes and more and more jurisdictions get on the same page, the discrepancies will diminish but there will always be those differences just as there are with NEC complaint systems.

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