Electrical Labeling Requirements for Solar PV Systems
Written by Jack Rubinger
The solar photovoltaic (PV) panel is the heart of the solar power system that has transformed the way business users are converting the sun's rays into useable, renewable electrical energy.
Driven by city, state and federal incentives, decreases in costs to manufacture panels and a desire to move toward a more sustainable energy resource, solar powered businesses will continue to be a changing part of our industrial landscape.
Each Solar PV System consists of thousands of panels found in large installations such as office buildings and power plants. These systems help produce electricity and come under the scrutiny of the National Electrical Code (NEC) which has strict standards about how these panels must be labeled for users.
While the NEC is not itself a US law, NEC use is commonly mandated by state and local law. To avoid costly delays and correction comments from the local authorities having jurisdiction (AHJ) we are providing a guideline to NEC electrical labeling requirements for PV panels.
Section 690 of the NEC specifies requirements for labeling PV systems. There are multiple labeling requirements, and they are spread out among several subsections. The labels, signs and placards are required to be a durable, unalterable material.
The first NEC requirement is that the PV power source information be posted at the DC disconnect, which may or may not be part of the inverter depending on local requirements. Section 690.53 lists the posting requirements: rated maximum powerpoint current, rated maximum power-point voltage, maximum system voltage, and short-circuit current. According to 690.14(C)(2), if there is more than one PV DC disconnect, they shall also be labeled.
The NEC also requires electrical labels for:
- The DC disconnect, noting that the line and load sides may be energized in the open position (NEC 690.17).
- The AC disconnect - stating the rated AC output current and nominal operating AC voltage (as stipulated by NEC Sections 690.14[C] and 690.54).
- At the location of the ground-fault protection, normally at the inverter, warning of a shock hazard (NEC 690.5[C]).
- Where the solar-electric system interconnects to the utility (NEC 690.54).
- General warning signs per article 705.10 NEC/CEC
Photovoltaic systems that include batteries have a few other electrical labeling requirements. In addition to NEC requirements, it is a good idea to also label other DC enclosures, the utility disconnect, and combiner boxes with fuses, while also providing information at the utility meter that there is a PV system connected.
In states such as California, there may be fifty different Building and Safety Jurisdictions with fifty different solar permitting fees, processes, timelines, levels of knowledge and signage and labeling requirements. Also, there’s a wide disparity between jurisdictions on what they require. It is imperative that installers inquire with the building department when pulling the appropriate permits.
Municipalities will also specify in their permitting requirements what type of signage is required at installation sites. They will be able to identify what stickers or placards are needed. They should also specify the colors, coatings and requirements for affixing the placards. Most municipalities will allow you to use adhesive to affix the placards and don't require rivets. That being said, some cities like Laguna Beach, CA require permanent fasteners like rivets or one way screws.
Solar labeling can be costly – especially if you purchase pre-printed labels. The upside of printing your own electrical labels is huge: Maximum efficiency, productivity, flexibility, convenience, portability, speed, high quality and availability of quality supplies.
One electrical label resource is DuraLabel, www.duralabel.com, which offers more than 50+ supplies, including UV and weather-resistant supplies and a complete family of thermal transfer printers for indoor and outdoor applications. All are easy to use and are compatible with all commonly used word processing software enabling installers to take charge of customizing and printing solar panel labels.