AUTHOR: Dean Austin

Electrical Room Basics, Part 1

This is the first in a series of blogs on electrical rooms Frequently, people associate an electrical room with Article 110 of the National Electrical Code® (NEC®).  More specifically, they associate it with section 110.26. But is that accurate? The answer would be kind of. Section 110.26 deals with what it calls working space about electrical equipment, not electrical rooms. After all, these rooms are sometimes used for other mechanical equipment like furnaces or water heaters, which is why they are sometimes referred to as mechanical rooms. The one thing they are not is storage rooms. The sections within 110.26 are specific to working spaces about electrical equipment that may or may not be within a room. Working space may be in a corridor, basement, exterior, or even a garage. However, the section that could be interpreted to require an electrical room is 110.27, which requires live parts be guarded against accidental contact. One of several methods to accomplish this is by placing electrical equipment in an electrical room or vault. Therefore, most architects design a separate electrical room, or mechanical room, for the main service equipment and mechanical equipment for the building, which is usually less expensive than an electrical vault. In most cases, the room is locked, which helps create a method of control to ensure only qualified persons have access to energized electrical equipment as outlined in 110.26(F). Contained within the electrical room is the working space about the electrical equipment as described in the 2023 NEC, section 110.26(A). This space consists of several parameters, some of which are outlined below. ·       Depth of Working Space is a measurement that considers nominal voltage to ground and if there are grounded parts or exposed live parts across from the equipment. This information lines up with the conditions outlined in Table 110.26(A)(1). To determine this measurement, one must select the condition that applies to the installation. Then measure from exposed parts (soon to be live) or from the face of the enclosure, if live parts are enclosed, extending out the front until the minimum distance within the table is achieved. ·       Width of Working Space is a dimension derived from measuring the width across the front of the electrical equipment. This can be taken from center (15 inches in middle of equipment), from left side of equipment or from right side. No matter the amperage the maximum width will be equal to the width of the equipment but will not be less than 30 inches. ·       Height of Working Space is measured from grade, floor, or platform to a height of 6.5 feet and is the width of the equipment or at least 30 inches and extends out to the depth of the working space. Other items such as luminaries or sprinkler pipes may be above this space, but not within it. ·       Grade, Floor, or Working Platform requires the grade, floor or working platform to be kept clear and that the floor, grade, or working platform be as level and flat as practical for the entire depth and width of the working space for the applicable working space. This is largely because electrical equipment that requires servicing may be in different environments. ·       Entrance to and Egress from Working Space requires at least one entrance of sufficient area to give access to and egress from the working space. Depending on the size of the equipment (see 110.26(C)(2)), the entrance and egress to/from the working space could be 24 inches wide by 6.5 feet high. Open equipment doors must not impede access to and egress from the required working space. If one or more equipment doors are open and access to and egress from the working space is reduced to less than 24 inches wide and 6.5 feet high, the access is considered impeded. Most of us have seen electrical equipment located outside of the electrical room. Sometimes a panel is in a corridor of a school or back hall of a store or even outside. Panels located outside of a building may require other means to guard the live parts from accidental contact and to create a compliant working space. No matter where the electrical equipment that may require servicing is located, all of section 110.26 applies. So, working space and section 110.26 must be accounted for by architects and design professionals in the overall layout and installation of electrical equipment to allow for safe access, operation, and maintenance of that equipment. Stay tuned to NFPA Today for part two in this blog series titled Electrical Rooms, where we will explore the working space requirements for equipment over 1,000 volts, nominal.
Temporary/holiday lighting

Holiday lighting: To inspect or not to inspect, that is the question

As the holidays approach us some may wonder, do I need an electrical inspection to hang my holiday decorative lighting? The answer is maybe. I know, probably not the answer you were thinking. The decision to require an inspection often lies with the authority having jurisdiction (AHJ) along with any applicable laws. The AHJ will likely consider the type of lighting or wiring that is being installed when making the decision. If you are just hanging a few twinkling decorative lights around the house and on trees an inspection might not be needed, but if you are putting on a holiday lighting extravaganza like Clark Griswold in Christmas Vacation, an inspection might be necessary, or probably should be. The 2023 National Electrical Code®, (NEC®), section 590.3(B) permits the installation of temporary holiday decorative lighting and associated wiring, as long as it is not up more than 90-days. This permission has nothing to do with the requirement or wavier of an electrical inspection but does provide the inspector with valuable information. Another question that comes to mind surrounding string lights, the ones that are hung around a patio or along a fence for ambiance, would that require an inspection? Possibly, since the string lights may be considered lampholders by the AHJ and are often left up for longer periods. NEC Article 410, Part VIII, and section 225.24 cover lampholders and their wiring. Because string lights are installed in a more permanent manner, frequently, a fixed and not temporary wiring method is used to supply the power. Section 590.2(B) indicates temporary wiring methods, including lighting, are acceptable only if approved based on conditions of use and any special requirements of the temporary installation. So how is it approved if it is not inspected by a qualified electrical inspector? Simple, it is not approved. So what is the AHJ looking for with temporary wiring or holiday decorative lighting installations? Typically, they are looking for: listing and labeling, sections 590.5, 410.6 wet locations for lampholders, 410.96 Location of outdoor lamps, section 225.25 installation methods, section 225.24, 590.2 So, as the holidays near and we start digging into the boxes in our basements and attics for holiday decor, now is the time to consider your approach to safety. Ensure your holiday decorative lights, string lights, and associated wiring are hung in a safe and code compliant manner and request an inspection where available. By reducing electrical hazards in your home, you can help assure you and your family will enjoy a fun, festive, and safe holiday season. NFPA has free resources to download and share, including a safety tip sheet on outdoor electrical safety, and a safety checklist. For more information, visit

Electrical space: the final frontier where electrical inspectors voyage to explore two of the many requirements of section 110.26(A)

Electrical space: the final frontier. “These are the voyages of the electrical inspector.” This plays on a quote from one of my favorite Star Trek movies. Space, especially electrical equipment space in buildings, can seem like it is a final frontier because it is getting harder to come by. Or is it? Prior to the COVID outbreak, buildings were being built to house hundreds, even thousands of employees, so space for electrical and mechanical rooms was at a premium and in tight quarters. Office space, especially when being rented by the square foot, was made a higher priority. With the way that many of us work shifting due to the pandemic, designs of buildings are likely to also start shifting to accommodate the move to a more remote workforce, which occupies less space within buildings. This may cause office spaces to be consolidated, therefore giving more room for electrical and mechanical rooms. Consolidation of space for offices may be occurring, but the change in how we work appears aimed more at having open spaces being converted to conference rooms for team meetings. But no matter what is occurring in the space designated for offices or meeting rooms, the one area that cannot be compromised is the spaces about electrical equipment. There are two types of spaces around electrical equipment mentioned in the 2023 National Electrical Code® (NEC®): working space and dedicated equipment space. Each one has quite different requirements, but all aid in the safety of the worker and longevity of the installation. Working space within the NEC, in general, is comprised of three parts: Depth of Working Space - found in section 110.26(A)(1). This measurement factors in nominal voltage to ground and if there are grounded parts or exposed live parts across from the equipment. Measurements are taken from live exposed parts or from enclosure if live parts are enclosed, out the front until the minimum distance found in Table 110.26(A)(1) is met. Width of Working Space –in section 110.26(A)(2). This dimension is derived by measuring the width across the front of the equipment. This can be taken from center (15 inches in middle of equipment), from left side of equipment or from right side. No matter the voltage or amperage the width will never be less than 30 inches. Height of working Space – addressed in 110.26(A)(3). This is measured from grade, floor, or platform to a height of 6.5 feet and is the width of the equipment or minimally 30 inches. All these spaces combine to form a box, if you will, that is for the qualified worker to occupy when servicing or working on the equipment. This is intended to provide room to move, which is necessary to keep them from bumping into something and possibly getting shocked or causing an arc flash. This area also allows easy access to equipment should a breaker or disconnect need to be shut off quickly. Working space is not to be used for storage according to 110.26(B). In all my years as an inspector I can’t tell you how many times I have had to write that violation during the electrical inspections. These mostly occurred on remodels where circuits and wiring were added to the existing electrical systems. I would politely remind the building owner/occupant that working space was required to help keep the electrical worker safe from exposure to electrical hazards that may be present. New to the 2023 NEC in section 110.26(A)(6) is the requirement that the grade, floor or platform in the working space be clear and as level or flat as practical for the entire required depth and width. The dedicated equipment space in 110.26(E) is just what you would think it would be; space dedicated solely for the installation of electrical equipment. Indoor dedicated electrical space is found in 110.26(E)(1)(a), which electrical inspectors often refer to as the “thumb print” of the equipment plus six feet above the top of the equipment. For example, a panelboard 20-inches wide x 6-inches deep mounted to the surface of the wall at seven feet to the top would have dedicate electrical space extending up to 13 ft above the finished floor. So the overall dedicated space is 20-inches wide x 6-inches deep up to 13 ft. In general, only electrical items are allowed within that space, which might include: raceways (and associated fittings) wireways junction boxes This list is not all inclusive, but an idea of what may be seen within the vicinity of electrical equipment. One exception to the dedicated space requirement is made for suspended ceilings with removable panels. With design limitations imposed on room size, there may be the occasional foreign system intruding into the dedicated electrical space required by section 110.26(E)(1)(a), typically becoming a violation. So, if the system was installed in accordance with 110.26(E)(1)(b), which addresses foreign systems over the dedicated electrical space, there would not be a problem. Remember our example, the top of the dedicated electrical space was 13 feet above finished floor, so the foreign system would need to be higher than 13 feet. If a foreign system is subject to condensation or leaks, the electrical equipment would require protection from such occurrences, which may also mean the system needs to be higher since the method of protection is not allowed within the dedicated electrical space. This space was put into the code to ensure adequate access to the electrical system for the installation of associated parts and to protect the electrical installation from other systems foreign to the electrical system. Electrical space: the final frontier where the voyages of the electrical inspector have explored two of the many requirements of section 110.26(A). Find more information for electrical inspectors by visiting You can explore the 2023 NEC by purchasing a printed copy or have NFPA LiNK® beamed to your computer.
A generator

Electrical Inspectors and Generators for Existing Dwellings

What is a generator and how do we inspect it on a residential application? Simply put, a generator is composed of two main parts, a prime mover, and an alternating-current or direct-current motor. The prime mover spins the motor causing an electromagnetic field to be induced onto the magnetic pole(s) of the motor. The number of poles the motor has, determines what the generator produces such as, single-, two-, or three-phase power. This is a very simple explanation. The generators can be permanently connected or portable. As inspectors we normally will not be looking at the internals of a generator since most are a permanently connected listed piece of equipment. Some gen sets use a combustion engine for prime mover or possibly a wind turbine, which could be fueled by natural gas or liquified petroleum gas (LPG). For this blog, we will discuss a permanently installed combustion engine type generator set being added to an existing residential dwelling. These installations are referred to in the NEC as optional standby systems and covered under article 702. The rating of most residential generators is not typically over 22 kilowatts (KW) and may be considered a gas fired appliance by the mechanical code. Frequently these installations require more than one inspector. When I was inspecting in the field, one of the initial items I requested was the installation instructions for the unit. This would provide additional information like clearances from buildings, windows, or doors, as well as specific wiring requirements. After proper clearances were verified, I would look for the disconnecting means required by the 2020 National Electrical Code® (NEC®), section 445.18 and they are: Emergency shutdown of prime mover – this disconnecting means is designed to disable the prime mover from inadvertently starting again and requires a mechanical reset to reengage the prime mover Remote emergency shutdown – this disconnecting means is applicable to generators over 15 KW rating and is located outside of the generator enclosure or equipment room, so this may affect larger one- or two-family dwellings. Emergency shutdown in one- and two-family dwelling units – this disconnecting means is for any generator at a one- or two-family dwelling and must be outside the dwelling in a readily accessible location. These disconnecting means should not be confused with the transfer switch, or the overcurrent protective device located within the generator housing for the feeder conductors running to the transfer switch. Being somewhat familiar with other codes I would frequently ask the installer or owner if they had contacted the utility company to determine if the current gas meter or regulator was sufficiently sized to handle the increased gas consumption created by the generator. Often, they had not. This may not seem important but asking this question may have saved them from being without the generator or heat when it was needed. Gas meters and regulators are typically sized for a specific cubic feet per minute flow at the time of installation, based on the amount of British Thermal Units (BTUs) required by the appliances in the dwelling. By adding additional BTUs to an existing gas meter without being upgraded could mean the gas fired appliances will not have sufficient gas flow to function properly. Inspectors asking questions, even when it is not within the area of your expertise, can almost always help avoid future problems for the customer. Moving to the transfer switch, I would determine if there was as an integral main overcurrent protective device (OCPD) and then inspect clearances around the switch. When a transfer switch contains an OCPD it frequently means the switch is an automatic transfer switch and is the service disconnecting means. For our scenario this is the case. I then would request a load calculation or provisions to automatically manage the load, sometimes called “load shedding.” Once that information was gathered, I would verify that the switch had a “suitable for use as service equipment” (SUSE) label, and that it had proper capacity, ratings, listing, and labeling. Since the transfer switch is the service disconnect it may also be serving as the emergency disconnect required in the 2020 NEC, section 230.85. Because the transfer switch is being used for both the service disconnect and the emergency disconnect, it must be marked as: EMERGENCY DISCONNECT, SERVICE DISCONNECT. Those markings should be on the exterior of the enclosure and comply with section 110.21(B). Adding emergency disconnects to the exterior of a dwelling is a way that the NEC allows first responders to safely disconnect all power within the structure, which will save time and lives in the event of a fire. Within the automatic transfer switch, I would also be verifying conductor sizes from meter, generator, grounding electrodes and new feeder to the old service panel as well as properly torqued terminations. The old service panel, typically inside the dwelling, new or existing, now has feeder conductors providing it with power instead of service conductors. Therefore, all neutral conductors must terminate on separate terminal bars from the equipment grounding conductors and the main bonding jumper between the neutral conductor and the panel enclosure must be removed if the panel is existing. If everything checks out, then I would have the installer initiate a power outage scenario to make sure all systems were functioning properly. This was not an overly deep dive into residential generator and optional standby system inspections, but a good overview of what to look for when conducting them. When on the job do not be afraid to ask questions; they can often lead to the discovery of a potential problem. Catching such issues early in the process allows us to readily address and fix the problem before it has the potential to harm us and others. To learn more about this and other related topics, go to the NFPA electrical inspection webpage and join us on NFPA Xchange where you can collaborate with other industry professionals, ask questions, and network with like-minded individuals We look forward to hearing from you!

An Electrical Inspector’s Role in Reducing Electric Shock Drowning

With dozens of papers and videos created around electric shock drowning (ESD) you would think that living and conducting electrical inspections in Michigan, a state with 3,288 miles of freshwater shoreline and numerous marinas, I would have known about ESD. Well, you would be wrong; I had no idea what ESD was until I started working at NFPA. I wondered if I was the only electrical inspector who was unaware, so I asked several inspector and electrician friends, and the answer was overwhelmingly, “No I do not, what is it?” This was shocking to me, but also provided me an opportunity to educate them. So, how can an electrical inspector have an impact? We must first answer the question of; what is ESD? According to the Electric Shock Drowning Prevention Association, it is the result of the passage of a typically low-level AC current through the body with sufficient force to cause skeletal muscular paralysis, rendering the victim unable to help himself / herself, while immersed in freshwater, eventually resulting in drowning of the victim. Higher levels of AC current in the water will also result in electrocution. It has been said that ESD is the catch-all phrase that encompasses all in-water shock casualties and fatalities. ESD occurrences happen more in freshwater environments than in salt water, which is why ESD is a concern around freshwater docking facilities, marinas, lakes, and ponds. Creating a specific code section in the NFPA 70®, National Electrical Code® (NEC®) for ESD may sound simple, but it is not. ESD is not a piece of electrical equipment or an electrical conductor but rather a phenomenon that can occur where boats in water are connected to shore power electricity. ESD is impacting the construction of boats, marinas, and docking facilities, which may help reduce occurrences of ESD. Even though ESD isn’t specifically addressed in the NEC, it has had a significant impact on recent changes that have been made in it. New solutions towards helping to eliminate ESD have become a regular subject in the code making process, public inputs, and comments for potential new NEC requirements. Although not finalized yet, suggested changes to the 2023 NEC that electrical inspectors should be aware of and that could have a positive impact on ESD reduction are: Emergency electrical disconnects within sight of the marina power outlets, which allows bystanders to quickly de-energize power to the boat and safely release a person who may be suffering an electric shock. Adding equipotential planes and bonding of equipotential planes that could help mitigate step and touch voltages for electrical equipment that supply power to the equipment. Requiring modified, repaired, or replaced equipment be updated to current provisions due to exposure to harsh environments. As conversations around ESD continue throughout the code development process it is important to remember the current requirements found in the 2020 NEC, and how electrical inspectors can use those sections to make an impact in reducing ESD. Through enforcement of electrical codes the inspector can help educate and inform owners and installers about ESD risks. Here are just a few code sections inspectors might want to be looking for: Signage - You might wonder, since when do electrical inspectors enforce non-electrical signage around marinas, boatyards, and docking facilities and how can they help prevent ESD? They can do it by continuing to warn everybody of the true dangers facing them. These areas are challenged with constantly changing environments because numerous boats in various degrees of electrical repair travel in and out of these facilities. This can make a place you may otherwise consider swimming in, potentially unsafe due to low-level AC current (leakage current). Installing permanent safety signs around marinas, boatyards and docking facilities gives notice of electrical shock hazard risks to persons within those areas. Signs should say more than “No Swimming” since some people may not take that warning seriously and swim anyway. Code language was added to have signs state: “No Swimming: “WARNING-POTENTIAL SHOCK HAZARD-ELECTRICAL CURRENTS MAY BE PRESENT IN THE WATER.” To aide in further preventing ESD, docking facilities was added in the 2020 NEC to the already existing areas of marinas and boatyards found in section 555.10. Ground-fault protection - Changes in the 2020 NEC, Article 555 Marinas, Boatyards, Floating Buildings, and Commercial and Noncommercial Docking Facilities address both ground-fault protection of equipment (GFPE) and ground-fault circuit interrupter (GFCI) protection. With cumulative effects of leakage current causing excess tripping of 30 milliampere GFPE devices, changes were made to code language that increased GFPE current settings not to exceed 100 milliamperes on feeders and branch circuits, which will cause inspectors to alter how they enforce this section. This change helped to facilitate more dependable power for marinas and docking facilities. However, individual branch circuits feeding single shore powered receptacles, must have individual GFPE devices set to open at currents not exceeding 30 milliamperes. Coincidentally, this requirement matches main breaker settings in boats manufactured after July 31, 2017. Leakage current measurement device - New 2020 NEC language allows electrical inspectors to require marinas, boatyards and docking facilities that have more than three receptacles supplying shore power to boats to have a leakage current measurement device available on site. This device would allow facility operators to isolate and notify boat owners of leakage current so repairs could be made by a qualified person, thus helping to eliminate a potential ESD risk. Private docks - Locations where ESD hazards may easily get overlooked or not inspected are on lakes surrounded by homes with private docks. These homes don’t always have shore power but may have electrically powered boat hoists. Section 555.9 was added requiring boat hoist outlets not exceeding 240-volts installed at dwelling unit docking facilities have GFCI protection for personnel. We have seen notable code changes within Article 555 over the last several cycles. Prior to the 2017 NEC, warning signs around marinas, boatyards, or docking facilities were not an NEC requirement, but they are now. GFCI and GFPE have had changes made within Article 555 over the 2017 and 2020 NEC cycles. Boat hoist GFCI protection was added to the 2020 NEC, plus numerous potential changes that may occur in the 2023 NEC cycle. There’s been a lot of positive influence on the codes because of the risks surrounding ESD, including regulating electrical requirements in marinas, boatyards and docking facilities, rendering them much safer now. But you still can’t swim there! As inspectors, we can help raise awareness of ESD in our communities. It starts with educating ourselves. Visit NFPA’s ESD web to learn more about this topic and ways to help mitigate the risk of ESD.
Structural reinforcing steel that serves as the pool shell bonding

Code Compliant Electrical Installation the Key to Swimmer Safety and a Secure Electrical System in Pools

Now that summer has arrived, many of us will be taking advantage of the nice weather to jump into swimming pools to cool off. But what many people don’t realize, is there’s a lot to keeping us safe from electrical hazards in these wet environments. Much of this depends on the initial electrical installation. Something that is often overlooked after the pool has been installed and inspected, is maintenance of the pool and associated pool equipment. As we all know, Father Time is not always kind to electrical installations, which may require re-inspections for safety. Based on changes to the 2020 National Electrical Code® (NEC®) the authority having jurisdiction (AHJ) is permitted to periodically inspect and test pools. If they so choose, municipalities can now implement a process to periodically inspect and test pools, associated pool equipment, and the equipotential bonding after the initial installation inspection to help ensure reliability and continued safety. A code compliant electrical installation for a pool, completed by a licensed qualified electrician, is vital to the overall performance of the electrical system and the swimmer’s ability to cool off safely. The conductive pool shell, perimeter surfaces, metal forming shell for underwater luminaires, ladder cups, diving board bracket, the water, and other metal surfaces are where the equipotential bonding system is found. This equipotential bonding system surrounds the pool with connections to a #8 AWG solid copper conductor. This solid copper conductor is terminated to all the above points then routed underground or within the concrete, back to the pool pump motor and terminated on the grounding lug located on pump motor. The NEC in Section 680.26(B)(6) requires sufficient length in the equipotential bonding conductor for future pump replacement. Best practice would be to provide enough additional conductor to terminate it anywhere on the motor in the event the lug is not in the same location. These connections are crucial to equalizing the electrical potential of all conductive surfaces, ladders, diving boards, underwater luminaries, and water that are all found with pools. Because pools are subject to corrosion and use corrosive chemicals, terminations, many of which are underground or within concrete, must be listed and labeled for the environment they are being installed in. People often think that once a pool is installed, all they need to do is add chemicals to the water and clean the pool. This myth is where problems arise as maintenance and periodic inspection and testing of the pool equipment is a very important part of the overall electrical safety of the pool. Ground Fault Circuit Interrupters (GFCIs) need to be tested in accordance with the manufacturer’s installation instructions, which is typically monthly. Also, as a part of the maintenance, grounding connections should be checked for corrosion, loose connections, or rust; all of these can inhibit the functioning of the equipotential bond, which could result in an electrical shock or an electric shock drowning (ESD). If corrosion is seen on any terminations, those points should be cleaned and or replaced by a qualified person as these connections are crucial to the safety of the people who use the pool. Pool pump motors do not last forever and therefore must be replaced, which requires the disconnection and reconnection of the equipotential bonding conductor from the motor. As previously mentioned, additional slack in the solid copper conductor is required at the motor location for motor replacement because consideration was taken for bonding lug location. When a state chooses to legislatively adopt the 2020 NEC, which makes it enforceable by an AHJ, Section 680.4 permits the periodic inspection and testing by the AHJ of the pool system. This may help encourage the maintenance and repair of the pool system and equipotential bond.   Maintenance on pools, associated pool equipment, and the equipotential bonding system is no different than maintaining a car by getting the oil changed. It is not difficult to do; the 2020 NEC provides this direction and is instrumental in helping to prevent a fun day at the pool from turning into a tragedy. Find additional information and resources for electrical inspection professionals at NFPA 70 the National Electrical Code® (NEC®) is 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   

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