The National Fire Protection Association (NFPA) released the 2014 National Electrical Code (NEC) last August. The 2014 edition, which will go into effect as states adopt it, has several changes that affect photovoltaic installations.
‘It was the first time where you saw a variety of solar-related provisions,’ says John Smirnow, vice president for trade and competitiveness for the Solar Energy Industries Association (SEIA). ‘There were a dozen or so relatively significant changes that were solar specific.’
Some of the changes are new standards for solar installations, and others are a rewording of current standards to cover solar. These were necessary, Smirnow says, because solar is growing as an industry. ‘If you think of any product that produces electricity, there is always going to be continuous improvement and updating,’ he says. ‘Being the new kid on the block, solar just had more changes because people are learning more about solar.’
The NFPA updates the code, technically referred to as NFPA 70, every three years, with assistance from representatives from the fire safety, electrical, renewable energy and other fields. SEIA's Codes and Standards Working Group was among the stakeholders involved.
The most important change, Smirnow says, is Article 690.12, ‘Rapid Shutdown of PV Systems on Buildings.’ According to this requirement, PV systems on or in buildings must be provided with a rapid shutdown function, which means the solar system must be able to be de-energized – reduced to 30 V – within 10 seconds in order to limit the risk of shock hazard to responders.
‘The idea there is when firefighters come out to the scene, they know the system will not be producing electricity outside the array,’ Smirnow says. ‘The proposal was largely to address concerns from the fire service community.’
Bill Brooks, an independent consulting engineer who has worked with the Solar America Board for Codes and Standards, says firefighters have long requested some type of disconnect for PV systems.
‘We've been holding them off for years, saying we need to do something coordinated and comprehensive,’ Brooks says. ‘Many jurisdictions and departments have been making up their own rules, not increasing safety but increasing costs.’
The solution, Brooks says, is an improvement over previous standards. ‘Where the fire department would go to shut things off, there was no requirement to have something at that point to shut off the solar array,’ he says. The code does not offer specifics on the shutdown mechanism, but Brooks notes that certain inverters and other equipment on the market would comply.
Also in the NEC 2014, Article 705, Interconnected Electrical Power Production Sources, covers arc fault detection and interruption and contains new language to reflect changes in inverters and other equipment related to solar.
Another change is the increase in voltage threshold from 600 V to 1,000 V. That code-wide change will help solar, says Jeremy R. Poling, energy and atmosphere subject matter expert for the U.S. Green Building Council (USGBC). ‘The way renewable energy systems are designed, it's easy to increase capacity and efficiency of systems to higher output voltage, so from that standpoint, it's beneficial in terms of what opportunities exist now for solar.’
Poling adds that the USGBC did not have a direct role in the code updates, but in general, the new code might benefit distributed solar. ‘As the building market moves toward the ideal goal of net zero energy, on-site generation will become more prominent,’ he says. ‘We like to encourage users to focus on safety first and not do anything unsafe in the name of building an efficient building.’
NEC 2014 is not mandatory, but it is available for states to adopt. According to the Electrical Code Coalition, so far Massachusetts and Nebraska are using NEC 2014, and 31 states have commenced their processes to use the updated code.
Installers need to be prepared, says Richard Lawrence, executive director of the North American Board of Certified Energy Practitioners (NABCEP). The changes will show up in questions on the certification test beginning in fall 2015.
‘It's not fair to a lot of candidates to be tested on the code until it's really in place,’ Lawrence says. ‘The code is not automatically in force. Some states are still using NEC 2008.’
NABCEP administers the certification test twice a year. Also, installers need to be recertified every three years, so current installers can take continuing education courses that cover the new code and other topics. The application deadline for the fall 2014 certification exams is July 18.
For more information on NABCEP certification, click here.
The NEC 2014 is available here.
Nora Caley is a freelance writer based in Denver.