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:
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: