I recently did a workshop for a major city experiencing problems with inspections on photovoltaic (PV) systems during and after installation. The problem was between the inspection and fire department. The inspection department—according to the fire code official—was inspecting the PV systems based on Article 690 of the National Electrical Code (NEC), but it was failing to require the appropriate signage and proper clearances for firefighting purposes. I was asked to locate a procedure that could aid in solving this problem. With the help of a California city, I located a procedure pertaining to the inspection of PV systems that satisfied both departments. The following procedure, “Signing and Marking: All photovoltaic systems shall be permanently marked as specified in this section,” was the one that the city reviewed for adoption.

A. Main Service Disconnecting Means

  1. Main Panel Exterior Marking. A placard is required to be permanently affixed to the main disconnect panel. The placard shall be red in color with white capital letters at least -in. in height and read as follows: SOLAR DISCONNECTING MEANS INSIDE PANEL. The placard shall be constructed of weather-resistant, durable plastic with engraved letters, or other approved material.
  2. Circuit Disconnecting Means Marking. A permanent label is to be affixed adjacent to the circuit breaker controlling the inverter or other PV system electrical controller. The label shall have contrasting color capital letters at least -in. in height and read as follows: SOLAR DISCONNECTING MEANS. The label shall be constructed of durable adhesive material or other approved material. Sections 690.5(C), 690.7(E)(3), 690.10(C), 690.17, 690.31(E)(3) and (4), 690.33(E)(2), and 690.35(F) can be very helpful for labeling and marking of various PV system components.

B. Direct Current (DC) Conduits, Raceways, Enclosures, Cable Assemblies, and Junction Boxes. Sections 690.31(E)(1) through (E)(4) and 690.31(F) can serve as an aid when conduits, raceways, enclosures, cable assemblies, and junction boxes are used to house DC related components. The following procedure is a recommended practice for DC supplied PV systems.

  1. Marking is required on all interior and exterior DC conduits, raceways, enclosures, cable assemblies, and junction boxes.
  2. Marking Locations. Marking shall be placed on all DC conduits, raceways, enclosures, and cable assemblies every 10 feet, at turns and above and below penetrations. Marking shall also be placed on all DC combiner and junction boxes.
  3. Marking Content and Format. Marking for all DC conduits, raceways, enclosures, cable assemblies, and junction boxes shall be red with white letter with minimum -in. capital letters to read: WARNING: SOLAR CIRCUIT. The marking shall be reflective, weather-resistant, and suitable for the environment. Materials used should be in compliance with UL Standard 969.

C. Secondary Power Sources. Where PV systems are interconnected to battery, generator backup systems, or other secondary power systems, additional signage acceptable to the electrical inspector and fire code official shall be required indicating the location of the secondary power source shutoff switch.

D. Installer Information. Signage acceptable to the electrical inspector and fire code official indicating the name and emergency telephone number of the installing contractor shall be required to be installed adjacent to the main disconnecting means.

E. No markings are required for inverters.

F. AC PV systems shall be marked as specified in this section.

  1. Main Panel Exterior Marking. A placard is required to be permanently affixed to the service disconnect panel. The placard shall be red in color with white capital letters at least -in. in height to read: SOLAR DISCONNECT INSIDE PANEL. The placard shall be constructed of weather--resistant, durable plastic with engraved letters, or other approved material.
  2. Circuit Disconnecting Means Marking. A permanent label is to be fixed adjacent to the circuit breaker controlling the inverter or other PV system electrical controller. The label shall have contrasting color capital letters at least -in. in height and read: SOLAR DISCONNECT. The label shall be constructed of durable adhesive material or other approved material. Review Sections 690.13 and 690.15 of the 2011 NEC.

Note that all signage and label letters shall be in a sans-serif font for a more positive identification of their meaning.

This article governs the requirements for providing the appropriate signage and marking of components making up a PV system installation and inspection. This identification procedure is necessary so that fire personnel can locate these systems easier when they are fighting fires in or on a facility. In the next installment of this three-part series, I will discuss building-mounted PV systems and the types of PV-output power circuits that must be installed properly and provide a reliable, dependable and safe PV system.


STALLCUP is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the National Electrical Code and other standards, including those from OSHA. Contact him at 817.581.2206.