Electrical safety is often described as a three-legged stool encompassing proper installation, routine maintenance, and applicable safe work practices. It is this relationship that sets the stage for what can best be described as the electrical safety ecosystem as it lives within the larger overall NFPA Fire & Life Safety Ecosystem™.
This Ecosystem is made up of eight key elements (Figure 1) that must all work together and are interdependent on each other. A breakdown in one element often leads to tragedy, and when it comes to electrical safety, the stakes are even higher.
On top of keeping the world working safely within this well-oiled system, industry professionals are tasked with keeping up with an ever-changing technological landscape. Equipment and building systems are evolving at a faster pace than ever before as manufacturers strive to solve issues with energy efficiency, equipment resiliency, building manageability, and cybersecurity. Keeping up with this changing industry is paramount to the success of the Ecosystem and that three-legged stool of electrical safety.
CODES AND STANDARDS
One of the key components of this ecosystem is that we develop and use codes and standards based on the most up-to-date information available. Imagine trying to stay on top of the dangers of today’s lithium-ion energy storage system (ESS) hazards if all we had were the installation requirements for storage batteries from the 1981 edition of NFPA 70, National Electrical Code® (NEC®)! This would be extremely problematic.
Fortunately, that is not the case. Today, we have specific requirements in a number of codes and standards that address the hazards with these ever-evolving battery technologies. However, requirements across multiple codes and standards means that those who design, install, and maintain electrical equipment have more places to look when they need to find the necessary information.
Energy Storage Systems
Take an energy storage system, for example. As an electrician, I immediately think of Article 706 in the NEC and Article 480 for storage batteries, if the ESS happens to employ batteries as the energy storage medium. But there is also the new standard, NFPA 855, Standard for the Installation of Stationary Energy Storage Systems. This standard addresses the minimum requirements for mitigating the hazards associated with ESS. Additionally, NFPA 1, Fire Code contains an entire chapter on energy storage systems from a fire danger standpoint. And a number of other codes and standards contain information like how these systems can serve an installation, how and when these systems must be maintained, how to work safely around ESS equipment, and how to address an ESS when there is a problem. All in all, at least half a dozen documents contain requirements for safety around energy storage equipment throughout its lifecycle.
As technology like ESS and solar/wind power generation becomes more prevalent in the built environment, this has become more of an issue. Today’s electrical systems seek to resolve issues with resiliency and efficiency. This has led to an increase in the number of systems utilizing this technology and has put terms like “microgrid” and “island mode” on the tip of everyone’s tongue in the NEC universe. With facilities aiming their sights squarely on establishing a system that can weather just about anything that comes their way and keeping energy costs to a minimum, microgrids seem to be popping up everywhere. This usually means an entire system that depends on solar/wind generation and ESS to stay operational, and it presents challenges from both maintenance and upkeep standpoints due to the hazards this type of system presents.
Let’s take a look at some requirements that will help keep us safe.
First, we must fully grasp and understand just what is meant by the term “microgrid.” There has been a lot of discussion around this term ever since it was added into the NEC, but it often seems as though folks are over-complicating the issue. In its basic form, a microgrid is defined in the NEC as:
“A premises wiring system that has generation, energy storage, and load(s), or any combination thereof, that includes the ability to disconnect from and parallel with the primary source.”
In other words, a microgrid is simply a premises wiring system that can stand on its own if need be and can operate in parallel with a primary source such as a utility-fed service. Not overly complicated when it comes to answering the question of “what is a microgrid.” However, let’s break down the individual components of a microgrid and explore the requirements there.
We’ll start by diving right into energy storage systems, in particular, battery-type energy storage systems. We will need to look in both the NEC and NFPA 855 for requirements related to the design and installation of these systems.
NEC Section 706.3
First and foremost, section 706.3 requires that only qualified persons as defined in the NEC install and maintain these systems. This means that only those individuals who possess skills and knowledge related to the construction and operation of the electrical equipment and installations and have received safety training to recognize and avoid the hazards involved are able to work on these systems.
Article 706 goes on to require other safety measures like how systems must be listed, disconnecting means configuration, circuit sizing, and capacity along with overcurrent protection, ventilation, and how to make the connection to an energy source.
ESS must also be maintained in safe and proper operating condition. This required maintenance must be in accordance with both manufacturer’s requirements and industry standards, and a written record must be kept of all maintenance and repairs performed.
One such document that provides industry knowledge for maintenance is NFPA 70B, Recommended Practice for Electrical Equipment Maintenance. However, in NFPA 70B, you are not going to find specific requirements for maintaining an ESS. You will find recommendations on how and why to establish an electrical preventive maintenance program. You will also find recommendations on what information to collect, how to collect it, and some basic fundamentals that make up maintaining these systems such as cleaning and personnel safety. However, the requirement for what needs to be checked, when it needs to be checked, and how it gets checked often comes from elsewhere like the manufacturer’s information.
Lastly, we also need to be thinking about other hazards associated with an ESS that are now incorporated into the installation when we install a microgrid. NFPA 855 addresses many of these other hazards. There are requirements within 855 for emergency planning for when something goes wrong, protection of thermal runaway incidents, and even explosion control to be implemented in accordance with NFPA 69, Standard on Explosion Prevention Systems. There are also requirements for fire protection systems depending on the type of ESS employed.
However, all of this only addresses the ESS portion of the microgrid. Don’t forget we must also address the other components. One of the more popular energy sources for microgrids is solar photovoltaic (PV) equipment, which has its own set of requirements to follow. NEC Article 690 addresses the installation of PV systems for safeguarding persons and property from the electrical hazards this type of equipment presents. Here we can find requirements for sizing conductors based on how much current the PV system will supply and how to protect those conductors from overcurrent. We’ll also find requirements for how to shut off the system intentionally as when adverse conditions exist. This requires isolation disconnects, rapid shutdown for emergency response, and arc-fault detection in order to shut the system down when it presents a hazard.
However, there are also requirements for grounding and bonding, safety marking and labeling of PV systems, and the same requirement as ESS systems that require only qualified persons to install PV system equipment and wiring components.
An entire chapter in NFPA 70B deals with the maintenance of PV systems. Here we can find recommendations on how to plan out a maintenance schedule to maximize the longevity of these systems and keep them performing as intended for years. The environment where we install these systems plays a crucial part in planning out how we take care of them as well.
For instance, PV systems are on nearly every building in California. If the building location is within close proximity to the ocean, the maintenance plan might need to include a procedure for cleaning the salt off of the modules and other associated equipment like the inverter and possibly the charge controller if the ESS is also installed where exposed to this environment. Another thing to maintain is labelling or marking. When the NEC requires us to mark something with the hazard present or leave a placard showing the location of other key components of the system, it is important that these labels are suitable for the environment where they will be installed. We must make sure we maintain them in legible condition and that the environment hasn’t damaged them beyond recognition.
These are just a few examples of where we need to begin when it comes to building out the electrical safety ecosystem. We find a number of requirements for qualified persons to install and service the equipment that makes up a microgrid. Having a skilled workforce is one of the key components to protecting the world from electrical hazards. We also want to make sure we are using the most recent editions of the various codes and standards since these are based upon the most recent information available to the industry.
We also need effective enforcement, which means that people in job roles like the AHJ must be aware of and stay current with industry trends and the latest requirements. However, enforcement isn’t always coming from the AHJ role. Many times, as is the case with safe electrical work practices, it is the employer who must enforce the rules. No matter who does the job, effective enforcement is critical to ensuring the highest level of safety.
All of this requires a significant investment in safety. There will need to be training, development of electrical safety plans and electrical preventive maintenance plans, and investments in new technology that provides new ways of approaching the electrical system within a building. We also need to keep pace with the changing trends in the industry. To do this the right way, electrical safety must be a place where no corners are cut. Replace equipment if we know it to be unsafe; make the investment now before the investment turns into fines and restitution. Be prepared to respond when the unthinkable happens. We can follow all aspects of the ecosystem, but if there is no emergency plan, we can still fail to provide that needed level of electrical safety when we have no idea how to respond to an event. Remember, people’s lives are often on the line when it comes to electrical safety.
When we bring all these pieces together to form our electrical safety ecosystem, it becomes more and more apparent just how much work we really have in front of us. With technology evolving on a daily basis, keeping up with what a person needs to know often seems an impossible task or at a minimum, a full-time job all by itself.
However, staying connected and getting involved will help keep us on that leading edge of knowledge and expertise that the world depends on us for. Keep in mind that, without those of us in the electrical industry with safety as a core principle for doing what we do day in and day out, the whole thing can come crashing down. The electrical world is a complex and often confusing world to navigate, but with a little help, we can achieve the level of safety we all strive for. Remember, it’s a big world. Let’s protect it together!
The NEC, NFPA 1, and NFPA 70B are now available in NFPA LiNK™, the association’s information delivery platform with NFPA codes and standards, supplementary content, and visual aids for building, electrical, and life safety professionals and practitioners. Learn more at nfpa.org/LiNK.
Derek Vigstol is Senior Electrical Content Specialist with the National Fire Protection Association (NFPA) in Quincy, Mass. He can be reached at email@example.com.