2013 CONFERENCE + EXPO ROUNDUP
New changes proposed for the 2014 NEC aim to boost safety related to home rooftop wiring, green power systems, RV parks, and more.
NFPA Journal®, May/June 2013
By Fred Durso, Jr.
Of the more than 3,500 proposals and 1,600 comments submitted for the 2014 edition of NFPA 70®, National Electrical Code® (NEC), a select handful is generating a healthy buzz.
One debate focuses on the growing residential use of arc-fault circuit interrupters (AFCIs), devices that are designed to detect electrical arcing and de-energize a circuit before a fire can occur. While proposals aim to expand AFCI use in homes, one group is arguing that increased use of the devices will only drive up the price of homes with no derived benefit. Cost is also at the center of another NEC debate over a proposal to further protect power sources at recreational vehicle (RV) parks, which has prompted pushback by the Recreational Vehicle Industry Association.
Green + Greener
A primer on NEC changes to safeguard renewable-energy technology and other systems
2013 NFPA Conference + Expo
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Jake West, Knowledge Services, UL LLC, Underwriters Laboratories, Inc.
Sunday, June 9, 8 a.m.–4:30 p.m.
Unclear about overcurrent devices and disconnects required for photovoltaic (PV) systems? Learn these and other specifics at a one-day seminar presented by NFPA and Underwriters Laboratories on designing, installing, and inspecting systems that harness the sun’s power.
Alan Manche, Schneider Electric; Jeffrey Sargent, NFPA
Monday, June 10, 8–9 a.m.
Up-to-date code provisions safely guide infrastructure upgrades, new technology utilization, and building construction. Learn how the NEC and other NFPA codes and standards aim to keep your community safe and sound. 2014 NEC Changes
Michael Johnston, National Electrical Contractors Association; Keith Lofland, IAEI
Tuesday, June 11, 11 a.m.–12:30 p.m.
Join NEC code-making panel members for their education session outlining and interpreting the most significant changes to the 2014 edition. Proposed Revisions to the 2014 NEC
Tim McClintock and Jeff Sargent, NFPA
Friday, June 14, 8 a.m.–4:30 p.m.
For a more in-depth look at the new edition, attend the one-day, post-conference seminar hosted by NFPA electrical specialists providing explanations on properly applying new code provisions to electrical inspections, installations, and designs.
Safety concerns regarding power systems using wind and solar energy resulted in proposals to increase the NEC's voltage threshold. Other proposals addressed rooftop wiring.
Topics receiving a Notice of Intent to Make a Motion (NITMAM) that become Certified Amending Motions (CAMs) will be posted at nfpa.org/70 in early May, and will be discussed at the Association Technical Meeting held at NFPA's Conference & Expo, June 10-13, in Chicago.
Arc-fault circuit interrupters
The 2011 edition of the NEC mandates the use of AFCIs. Hammering a nail into a wall and piercing electrical wiring can cause electrical arcing that can ignite combustible construction materials within the wall, as can deterioration of a wire or its insulation. That's why the NEC requires AFCIs for circuits supplying power to various rooms - bedrooms, dining rooms, and hallways, to name just a few - in all new dwellings. A provision also requires AFCI protection for modified, replaced, or extended circuits in existing dwellings.
"An AFCI is like having an electrical inspector in your home 24/7," says Thomas Domitrovich, national application engineer for Eaton Corp., a producer of electrical devices, including AFCIs. He also sits on the technical committee for NFPA 73, Electrical Inspections for Existing Dwellings. "If there's a problem, it's going to find it."
Since AFCIs identify electrical glitches that can go undetected by standard circuit breakers, the NEC has continually expanded AFCI use. The 2014 code cycle is no exception; proposals for the next edition of the code include increasing AFCI use beyond a home's electrical panel to its electrical outlets as well.
At odds with these proposed changes is the National Association of Homebuilders (NAHB), which argues that the cost of AFCIs will drive up home prices. (NAHB abstained from public comment voting.) An AFCI can cost upwards of $35, while standard circuit breakers can be under $10. "Despite repeated attempts by NAHB and several other affected parties to show that there have been no decreases in the number of electrical arcing fires…the NEC code-making panel continues to expand AFCI protection incrementally, without providing any concrete evidence or supporting data that AFCI protection has resulted in fires being prevented," says Steven Orlowski, a representative for NAHB who sits on an NEC code-making panel.
NFPA does not test, label, or approve products, but Underwriters Laboratories and the Consumer Product Safety Commission have field-tested AFCIs and found the devices to be reliable and effective. These results were the basis for the NEC requiring the use of these devices. NFPA statistics further the cause for increased protection against electrical fires. The 2013 NFPA report "Electrical Fires" shows that electrical failure or malfunction was a factor contributing to ignition in 84 percent of electrical distribution equipment home structure fires. Arcing (indicating an arc fault) was specifically cited for at least 77 percent of these electrical failure home fires involving electrical distribution equipment.
Electrical fires in kitchens
Electrical kitchen fires have also led to proposals on expanding AFCI use. A proposal from consumer appliance manufacturer General Electric, also citing similar NFPA research on electrical failure and malfunctions, requested AFCI use in kitchens - specifically, for dishwasher circuits only. Electrical malfunctions resulted in an annual average of 700 home dishwasher fires between 2005 and 2009, according to NFPA's "Home Electrical Fires" report.
The code-making panel "has recognized the fire prevention capabilities of AFCIs by expanding the areas requiring AFCI protection in the 2008 NEC code-making cycle," says Jay Broniak, a GE engineer who submitted the proposal, in his proposal's substantiation. "Further expansion…is necessary to help minimize the risk of fire to dishwasher circuits."
The National Electrical Manufacturers Association took this idea a step further by developing its own proposal, which suggested AFCI use in all 120-volt, single phase, 15- and 20-ampere branch circuits in all dwelling units, not merely for the rooms listed in the 2011 NEC.
The panel did agree to expand the use of AFCIs incrementally by adding kitchens to the list, but it rejected the device's use in all 15- and 20-amp branch circuits.
Voltage threshold increase
Technology designed to harness sustainable energy sources continues to hit the marketplace, but is the NEC equipped to handle the requirements of these systems?
That was the question recently faced by the NEC High Voltage Task Group, which examined how the NEC could address green energy systems - specifically, wind power and solar photovoltaic systems - that operate above 600 volts. There were 120 proposals submitted for the 2014 NEC code cycle that sought to boost the code's voltage threshold from 600 volts (and subsequent requirements at this capacity) to 1,000 volts, an increase intended to address the energy and safety needs of these systems.
"The 600-volt figure has been long established in the code, and we never had any issue with it until renewable energy systems connected to building wiring had output voltages that started exceeding 600 volts," says Michael Johnston, executive director of Standards and Safety for the National Electrical Contractors Association and chair of the NEC Technical Correlating Committee. This would have required the use of distribution equipment rated over 600 volts. "The NEC needs to be equipped to handle these circumstances," Johnston adds.
Also driving this voltage increase was the concern that the newer-technology equipment could be more difficult to use under existing NEC requirements..
The High Voltage Task Group proposed a 1,000-volt threshold to accommodate this new equipment. "We don't know if [the threshold limit] will stay at 1,000," says Johnston. This had become the dividing line for low-voltage distribution equipment. In some technical committees of other standards developers, higher voltage limits are being discussed for low-voltage distribution equipment.
"There were a few panels that didn't accept the proposals across the board because they wanted more research on this issue," Johnston says, adding that this research will likely take place between the Annual 2014 and 2017 code cycles.
Despite the pushback, the majority of code panels favored the increase, says Jim Dollard, chair of the High Voltage Task Group and safety coordinator for the International Brotherhood of Electrical Workers Local 98 in Philadelphia, Pennsylvania. "The enforcement community will have an easier time looking at these installations and reviewing and inspecting them in accordance with the NEC," he says.
'Structures' in RV parks
The NEC provides provisions for "electrical conductors…installed within or on recreational vehicles (RVs), conductors that connect recreational vehicles to a supply of electricity, and the installation of equipment and devices related to electrical installations within a recreational vehicle park."
Related to the issue of RV safety in the NEC is a provision on grounding, which prevents shock or electrocution by sending an unwanted electrical current - from a lightning strike or short circuit, for example - out of harm's way and into the earth. A proposal sought to expand grounding requirements for RV pedestals, a type of power outlet panel found at RV parks and campgrounds.
According to the proposal, these pedestals should be considered "structures," which the NEC defines as "that which is built or constructed," and should be required to comply with grounding requirements found in Article 250. An NEC code-making panel unanimously approved the proposal, according to the NEC Report on Proposals, but then reversed its position during the public comment vote.
The proposal arose out of a lack of understanding of existing safety protocols in the RV industry, says Bruce Hopkins, vice president of standards and education for the Recreational Vehicle Industry Association and a member of the panel that originally accepted, and ultimately denied, the proposal. "People don't understand our business, and that sets the stage for potential conflicts," he says, noting that RVs and RV pedestals already have over-current protection devices. The pedestals, he adds, are considered pieces of equipment - not structures - and are incorrectly compared to portable electrical distribution panels used at construction sites and subjected to grounding requirements. Hopkins says installing the necessary grounding rods at RV parks, where the pedestals are numerous, would entail "excessive cost with no additional safety."
Others disagreed with the panel's final vote, arguing that the pedestals should in fact be treated as structures. Among them was Ron Chilton, chief electrical engineer and state electrical inspector for the North Carolina Department of Insurance in the Office of the State Fire Marshal. Chilton also sits on the code-making panel that accepted, then rejected, the proposal during the comment stage. "In my opinion, I don't think the panel has the authority to say, 'We're not going to require grounding for pedestals,'" he says. The issue pertains to the definition of "structure" found in the NEC, he argues, and to the code's extensive grounding requirements - neither of which is covered by the scope of the code-making panel.
Cables and conductors on rooftops
The NEC provides requirements for circular raceways, which are enclosed channels of metal or nonmetallic material designed to hold wires or cables. Research has indicated that exposure to direct sunlight might make a raceway hotter than its ambient temperature and compromise its properties, and the code lists temperature values, or "adders," to the ambient temperature for use mainly by installers and designers to prevent conductor damage due to the elevated temperature where installed in direct sunlight on a rooftop.
These values, however, have been called into question because there has never been a verified report of failure of rooftop wiring in a raceway exposed to sunlight, according to some panel members. In addition, the Copper Development Association (CDA) wants to increase these values following a series of recent tests witnessed by Underwriters Laboratories (UL). Initial tests conducted by UL led to the values listed in the 2011 NEC, but the study didn't take into account other forms of raceways.
Based on tests, the CDA submitted a proposal to increase the ambient temperature adjustments on rooftops, but the code-making panel responsible for this information chose to retain the values in the 2011 NEC. Christel Hunter, a director with General Cable, a worldwide wire and cable manufacturer, and NEC panel member, submitted a proposal requesting that an exception to the adder provision be made for a specific type of insulation. The panel rejected the proposal, but expressed interest in laboratory testing that could substantiate the exception. Hunter says that testing confirmed high temperatures posed no safety risk to the insulation when it was placed on rooftops. The panel accepted the comment in principle, limiting the exception to Type XHHW-2 cable.
Fred Durso, Jr. is staff writer for NFPA Journal.
Green + Greener
A primer on NEC changes to safeguard renewable-energy technology and other systems
Like the 2011 edition of NFPA 70®, National Electrical Code®, the 2014 edition of the NEC will also feature a number of changes designed to increase safety related to a variety of green technologies.
Hazard marking for alternative energy systems became an important issue this code cycle, and proposed new requirements and an "informational note" in Article 110 of the NEC will address hazard markings for all systems covered by the code. The requirements will address hazard marking signage details including legibility and durability, and are designed to help provide clearer, more effective hazard warnings to electrical workers, inspectors, and anyone else working in close proximity to these systems. It also references a standard that provides details on words, colors, and symbols.
"We've had warning markings in the NEC for a while," says Mark Earley, NFPA's chief electrical engineer, "but these new requirements provide a more standardized approach to help provide more effective signage."
Locking and disconnecting
Another NEC-wide change with important ramifications for renewable-energy technologies is a proposed new section that would standardize requirements for "locking" and "disconnecting" the power source so that electrical equipment can't be accidently re-energized during maintenance or repair. "The idea is to ensure that when equipment is disconnected and locked out, that you make sure it's truly disconnected and locked," says Earley. "These new centralized requirements will make that process clearer and easier to follow."
PV and wind turbine shutdown
Related to disconnection and lockout are new requirements for the shutdown of photovoltaic (PV) systems and wind turbines. For PV systems, Earley says, the idea is to be able to shut a system down rapidly for maintenance or to fight a fire. "PV is unique in that if you disconnect it during daylight hours, it can still be energized," he says. "This is a real concern for the fire service-they can't just call the utility to come out and shut a PV system off, because in most circumstances the system doesn't belong to the utility." The new provisions would outline how to shut down such systems quickly, and how to make sure the system is no longer energized and is safe to work around.
New shutdown procedures are also included for wind turbines, including a readily accessible shutdown button or switch that would either stop the turbine rotor or de-energize the turbine output circuit.
Like the 2011 edition of the NEC, the new edition also includes important proposals aimed at electric vehicle (EV) charging technology. One proposal provides new requirements for branch circuits that supply power to EV charging equipment, specifying that these circuits should be dedicated to EV charging equipment in order to prevent circuit overload.
DC and energy conversion
Another set of new requirements that could affect alternative energy sources addresses direct current (DC), specifically in the conversion processes that can result in lost energy. "PV systems, for example, generate energy in DC, which is then converted to AC," Earley says. "Wind power is generated in a sort of 'dirty' AC that's converted to DC, then finally back to AC. Each time you do a conversion you lose a little bit of energy, and the idea with these requirements is to save that energy by eliminating some of the conversion."
Energy management systems and smart grid
Finally, Article 750 will introduce energy management systems (EMS) into the NEC. While not specific to alternative technologies, EMS can be an important component of smart grid power management, a grid-wide approach to creating a consistent supply of power based on predicted needs. EMS can be particularly useful for managing the load for multiple electric vehicle charging stations. It would allow a facility's electric vehicle supply equipment (EVSE) energy load to be spread over the course of a day, allowing for smaller, more economical systems.
"If you have a commercial property with EV charging stations, for example, the code requires you to factor in all of the EVSE loads as continuous loads, this could require some very large equipment to supply that very large load," Earley says. "EMS allows you to switch where that power is going over the course of the day, spreading it out, so you're doing it much more efficiently and with a smaller system."
The new article, which will focus on EMS use in commercial and industrial campus applications, was produced by the correlating committee's Smart Grid Task Group.