690.31(G)(1) Beneath Roofs.
Code Change Summary: Requirements to keep the DC PV wiring methods at least 10 in. under the roof sheathing have been deleted.
In the 2011 NEC®, section 690.31(E)(1) required DC PV system conductors to be installed at least 10 in. below the roof deck or roof sheathing unless these wiring methods were directly below the PV modules and associated equipment. This prevented accidental damage caused by saws used when firefighters vented the roof during a fire.
In the 2014 NEC®, this section has been deleted. When looking into the archived code proposals and associated comments, there is no real indication as to why this section was removed but it is likely that the code panel felt it unnecessary since the new requirements in 690.12 for rapid shutdown were introduced. After the firefighter initiates the rapid shutdown function, there will be no live PV system wires to cut into even if they are installed directly under the roof sheathing.
With the deletion of this code language came the addition of 690.31(G)(1). This new section contains the following code language which was similar to what was previously found in 690.4(F):
690.31(G)(1) Embedded in Building Surfaces. Where circuits are embedded in built-up, laminate, or membrane roofing materials in roof areas not covered by PV modules and associated equipment, the location of circuits shall be clearly marked using a marking protocol that is approved as being suitable for continuous exposure to sunlight and weather.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).
2011 Code Language:
690.31(E)(1) Beneath Roofs. Wiring methods shall not be installed within 25 cm (10 in.) of the roof decking or sheathing except where directly below the roof surface covered by PV modules and associated equipment. Circuits shall be run perpendicular to the roof penetration point to supports a minimum of 25 cm (10 in.) below the roof decking.
Informational Note: The 25 cm (10 in.) requirement is to prevent accidental damage from saws used by fire fighters for roof ventilation during a structure fire.
2014 Code Language:
690.31(E)(1) has been deleted.
690.31(G)(1) Embedded in Building Surfaces. Where circuits are embedded in built-up, laminate, or membrane roofing materials in roof areas not covered by PV modules and associated equipment, the location of circuits shall be clearly marked using a marking protocol that is approved as being suitable for continuous exposure to sunlight and weather.