AUTHOR: Dean Austin

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, 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. With the changes that occurred in the 2020 National Electrical Code® (NEC®) the authority having jurisdiction (AHJ) is permitted to periodically inspect and test pools. If municipalities so choose, they can implement a procedure 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, a reconstructed conductive pool shell, perimeter surfaces, metal forming shell for underwater luminaires, ladder cups, diving board bracket, the pool 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 2023 NEC, in Section 680.26(B)(6)(a) 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. Maintenance requirements for public pools, fountains, and similar installations, excluding one- and two-family dwellings, can be found in NFPA 70B, Standard for Electrical Equipment Maintenance, chapter 34. 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 periodic maintenance procedures found in section 34.3 of NFPA 70B, the 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 visible 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 incorporate by reference the 2023 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 2023 NEC along with NFPA 70B provide this direction and are instrumental in helping prevent a fun day at the pool from turning into a tragedy. NFPA 70 the National Electrical Code® (NEC®), and NFPA 70B, Standard for Electrical Equipment Maintenance, is 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.

An Electrical Inspector’s Role in Reducing Electric Shock Drowning

A version of this blog was originally published in 2022. It has been updated to reflect the most recent information. You would think that as someone who lives and previously conducted electrical inspections in Michigan, a state with 3,288 miles of freshwater shoreline and countless marinas, I would have known about electric shock drowning (ESD) before joining NFPA®. Well, you would be wrong; I had no idea what ESD was until I started working at NFPA. At a recent electrical inspectors’ conference, I began to wonder if I was the only inspector who had been in the dark about ESD. I asked if anyone knew what ESD was, and very few did. This was surprising to me, but also provided me with an opportunity to educate them. So, how can an electrical inspector have an impact? We must first answer the question, “What is ESD?” RELATED: Learn more about the NFPA Electrical Inspection Membership According to the Electric Shock Drowning Prevention Association, ESD occurs when a typically low-level alternating current (AC) passes through the body with sufficient force to cause skeletal muscular paralysis, rendering a swimmer in freshwater unable to keep him or herself afloat, eventually resulting in the drowning of the victim. Higher levels of AC in the water could also result in death via electrocution. It has been said that ESD is the catch-all phrase that encompasses all in-water shock casualties and fatalities. ESD occurs more in freshwater environments than in saltwater, which is why ESD is of particular concern around freshwater docking facilities, marinas, lakes, and ponds. Creating a specific code section in 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 in areas where boats are connected to shore power electricity. Increased knowledge on the risk of ESD has impacted the construction of boats, marinas, and docking facilities, which may help reduce occurrences of ESD. And 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 for helping eliminate ESD have become a regular subject in the code-making process, public inputs, and comments for potential new NEC requirements. Changes to the 2023 NEC that electrical inspectors should be aware of and that could lead to a reduction in electric shock drowning deaths include the following: Requiring emergency shutoff devices or emergency disconnects located within sight of the marina power outlets or other enclosures providing power to boats. They are to be marked “Emergency Shutoff,” readily accessible, and externally operable, 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 that modified, repaired, or replaced electrical enclosures, devices, or wiring methods comply with the current provisions of the NEC. The installation also requires the circuit be inspected due to exposure to harsh environments. Requiring all luminaires and retrofit kits to be listed and identified for use in their intended environment. Also requiring that luminaires installed below the highest tide level or electrical datum plane and likely to be periodically submersed comply with 555.38(B). As conversations around ESD continue throughout the code development process, it is important to remember which edition of the NEC is being enforced in your area, and how you as an electrical inspector can use those sections to make an impact in reducing ESD. Through enforcement of electrical codes, the inspector can help educate owners and installers about ESD risks. Here are just a few topics inspectors might want to look up in the NEC: Signage – You might be wondering, “How can signs 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 all the time. This can make a place you may otherwise consider swimming in potentially unsafe due to the presence of low-level AC (leakage current). Installing permanent safety signs around marinas, boatyards, and docking facilities gives notice of the ESD risk 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 aid in further preventing ESD, docking facilities were added to the list of marinas and boatyards found in 555.10 of the 2020 NEC. Ground-fault protection – Article 555, Marinas, Boatyards, Floating Buildings, and Commercial and Noncommercial Docking Facilities, addresses 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 the code language for the 2023 edition of the NEC that increased GFPE current settings not to exceed 100 milliamperes on feeders and 30 milliamperes on branch circuits, which will require inspectors to verify devices are properly located in the electrical system. This change helps facilitate more dependable power for marinas and docking facilities. Branch circuits feeding single shore power receptacles must still 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. Outlets for non–shore power had the GFCI protection for personnel expanded in the 2023 NEC to cover 150 volts to ground and 60 amperes, single phase, and 150 volts or less to ground and 100 amperes or less, three phase. Leakage current measurement device – The 2020 NEC language allowed 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. The new language in the 2023 NEC requires the device to be listed for use in marina applications. This requirement doesn’t become effective until January 1, 2026. 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 555.35(C) requires boat hoist outlets not exceeding 240 volts installed at dwelling unit docking facilities to 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, 2020, and 2023 NEC cycles. 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 this webpage to learn more about this topic and ways to help mitigate the risk of ESD.

Article 90: Why It’s So Important for Electrical Inspectors

Some people may not consider Article 90 of NFPA 70®, National Electrical Code® (NEC®), to be a backbone of electrical inspector knowledge. But a familiarity with Article 90 is crucial for electrical inspectors. The sections found within Article 90 provide a comprehensive overview of when the NEC applies and when it doesn’t, how the code is arranged, and how enforcement works—all information that is valuable to any electrical inspector. In this blog, we’ll go over some of the information in Article 90 that is important for electrical inspectors to know. What does the NEC cover? Section 90.2(C) lists areas covered by the NEC, and they are: 1.     Public and private premises, including buildings, structures, mobile homes, recreational vehicles, and floating buildings 2.     Yards, lots, parking lots, carnivals, and industrial substations 3.     Installation of conductors and equipment connecting to the supply of electricity 4.     Installations used by electric utility, such as office buildings, warehouses, garages, machine shops, and recreational buildings, that are not an integral part of a generating plant, substation, or control center 5.     Installations supplying shore power to ships and watercraft in marinas and boatyards, including monitoring of leakage current 6.     Installations used to export power from vehicles to premises wiring or for bidirectional current flow As you can see, the NEC addresses installations and methods of accomplishing those installations in its areas of coverage. The fifth item was added in the 2020 edition of the NEC to address installations of shore power and associated receptacles in marinas and boatyards, which may help lower the risk of exposure to electric shock drowning (ESD) through specific changes made in Article 555. The sixth item was also added in the 2020 NEC to deal with new technology around electric vehicles (EVs) and their ability to provide power to premises electrical systems through the EV charging equipment. The changes are reflected in Article 625. What doesn’t the NEC cover? Just as important as knowing what the NEC covers is knowing what it doesn’t. Section 90.2(D) lists the areas that are not under the purview of the NEC, which helps electrical inspectors navigate the out-of-bounds line. This is not to say there are no electrical inspections happening in those areas—just that if there are any, they are likely done using a code or standard other than the NEC for determining compliance. For example, utility-owned service or transmission line installations are covered by the National Electrical Safety Code (NESC) and not the NEC. How is the NEC arranged? The NEC arrangement is outlined in Section 90.3. The NEC is organized so that the requirements found in Chapters 1 through 4 apply generally to all electrical installations referenced in the code, except those referenced in Chapter 8, where the code language must have specific references to the first four chapters. This arrangement helps consolidate general requirements into a few chapters so that they’re not repeated elsewhere in the NEC, which makes it easier for electrical inspectors and installers to locate. Enforcement Information for electrical inspectors around enforcement, interpretations, specific requirements, and what to do with new products, constructions, or materials is found in Section 90.4. According to 90.4(A), the NEC is suitable for mandatory application by governmental bodies that have legal jurisdiction of electrical installations. These bodies are usually state, county, or city governments that incorporate the NEC by reference into their rules or laws. In most instances, electrical inspectors must be working under the authority of an enforcing agency or for an authority having jurisdiction (AHJ) to have any enforcement powers over permitted electrical installations within those jurisdictional boundaries. AHJs have the responsibility for making interpretations of the rules and for deciding on the approval or rejection of equipment or materials used in electrical installations. They may also grant special permission in certain circumstances as they deem necessary. There are two types of rules in the NEC: mandatory and permissive. They are expressed very differently. Mandatory rules are the shall or shall not rules. For example, a mandatory rule would be “the electrical connection of conductors to terminal parts shall ensure a mechanically secure connection without damaging the conductors,” whereas a permissive rule would be “reconditioned equipment shall be permitted except where prohibited elsewhere in the NEC.” As a former AHJ, I frequently would tell electrical inspectors that the code isn’t what you THINK it says; it is what it SAYS it is, so go read the code section before writing a violation or approving an installation. Understanding the difference between mandatory and permissive rules can help the enforcer-installer relationship by having a more accurate inspection. Where to go for more information Electrical inspectors, you are not alone in what you do. NFPA® has an Electrical Inspection Section membership just for you, where you can network with other electrical inspector members. Inspectors can share ideas, talk code, and collaborate on interpretations of the code through NFPA XchangeTM. Having these tools will help create a more consistent enforcement of the NEC.

Electrical Room Basics, Part 3

This is the last in a three-part series on electrical rooms. Read Part 1 here and Part 2 here. Working space about electrical equipment is covered in Article 110 of the NEC.  Up to this point, we have discussed electrical rooms and how the National Electrical Code® (NEC®)—specifically, 110.26—helps ensure there is enough space, especially working space, in those rooms or areas. In Part 2, we observed that changing the voltage alters some of the clearance requirements for the equipment in electrical rooms (see 110.32 and 110.34 of the NEC). Now, we will look at an electrical enclosure, vault, or tunnel that is being used as a method for guarding electrical equipment and see how it affects clearances for working space about electrical equipment. What is an electrical enclosure?  First, let’s look in Article 100 to see if there is a definition for a vault or tunnel. We find there isn’t one, but we do find a definition for enclosure. Enclosure is defined as “the case, housing of an apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.” So, does this definition cover an electrical room or vault? I think it could, because the vaults are areas typically surrounded by walls and frequently some form of lockable entrance. Does a vault or enclosure still require working space for electrical equipment? Yes, Parts II and III of Article 110 cover these requirements. For voltages of 50 to 1000 volts, nominal, 110.27(A)(1) would address the use of a room, vault, or similar enclosure that is accessible only to qualified persons, as a means of protection against accidental contact with live parts. For the over 1000 volts, nominal, installations, 110.31(A)—which deals with electrical vaults, including their construction requirements—would apply. Often, we see vaults being utilized as electrical rooms for installations over 1000 volts versus the under-1000-volt installations. This is in part due to electrical installations using exposed terminations or the use of larger substations and switches, which could increase the risk of accidental contact with live parts, depending on the type of equipment. Construction of enclosures  Construction of the vault roof and walls must not be made from studs or wall board, but instead from construction materials that will provide adequate structural strength for the conditions and possess at minimum a 3-hour fire rating. This is usually accomplished using materials that are made from or contain concrete, like a masonry block wall with pre-cast concrete planks for the roof and floor, or a complete pre-cast concrete unit. Where the floor is in contact with earth it must not be less than 4-inch-thick concrete. However, where vacant space or stories are below the floor, it may need to be engineered to be able to structurally withstand the loads imposed on the floor. A vault will normally have access doors as well, which are required to be tight-fitting and have a 3-hour fire rating, unless the vault has an approved fire suppression system installed, in which case the doors can be 1-hour fire rated. These doors must also be lockable, to restrict access to unqualified persons. To allow safe egress in the event of an electrical injury, the doors must be equipped with panic hardware and open 90 degrees in the direction of egress. Don’t forget the signage that must be on the doors (See Part 2 in this blog series for more on signage). Should an electrical catastrophic failure occur, the vault’s robust construction will help mitigate damage to other portions of the building, which could ultimately save lives. This type of heavy-duty construction requires detailed planning from the electrical contractor and design professional for all electrical equipment locations and the penetrations into the vault from feeders, branch circuits, or raceways that will be connecting to that electrical equipment. These penetrations must not reduce the rating of the vault. The electrical equipment contained in the vault, such as the switchgear, transformers/substations, and motor control centers (MCC), must meet the working space requirements found in 110.26, 110.32, and 110.34 of the NEC. The applicable NEC section is determined by the highest nominal voltage for the equipment in a particular area, since there may be more than one voltage within a vault. Where high-voltage equipment is contained within the same vault as equipment 1000 volts or less, there may need to be some separation in accordance with 110.34(B). If the separation is accomplished with a fence controlled by locks, then 110.31 would apply. Table 110.31 contains distance values for the required space between the equipment and the separating fence. Note that the fence cannot be within the working space measurements found in Table 110.34(A). Adding electrical equipment in a vault does not reduce the working space requirements found in 110.26 or 110.34. It just adds some additional items to work around. Whether your electrical equipment is in an electrical room or a vault, you must maintain proper clearances for worker safety. A great way to learn more about working space about electrical equipment is to register for the NFPA online training series on the 2023 edition of the NEC. Working space about electrical equipment is covered in the General Equipment Installation Practices section of this training. Learn more about this comprehensive, self-paced training.  

Electrical Room Basics, Part 2

This is the second in a series of blogs on electrical rooms. Read Part 1 here. In my previous blog, we discussed the misconception that electrical rooms are covered in 110.26 of NFPA 70®, National Electrical Code® (NEC®), when they are actually covered as an option for guarding against accidental contact with live parts in 110.27. Now, we will explore the electrical room and working space for equipment over 1,000 volts, nominal. Does 110.26 still apply to that working space within the electrical room? The answer would be no, because 110.26 is in Part II of Article 110, which covers installations under 1,000 volts, nominal. The applicable part of 110 is Part III: Over 1,000 Volts, Nominal. Specifically, 110.32, Work Space about Equipment; 110.33, Entrance to Enclosures and Access to Working Space; and 110.34, Work Space and Guarding. Coincidently, these sections have some similarities to 110.26, such as requiring: ·       Height for working space of 6.5 feet, measured from floor or platform ·       Working space not to be used for storage ·       90-degree opening of equipment doors or hinged panels ·       Equipment doors not to impede entrance to and egress from the working space ·       Grade, floor, or platform to be as level as practical for the entirety of the working space ·       24-inch wide by 6.5-foot high entrance to and egress from the working space As you can see, the NEC correlates sections with one another when it makes sense. There are, however, a few differences among these sections, one of which is the width of the working space. Section 110.26(A)(2) allows a minimum width of 30 inches for working space, while 110.32 allows a minimum width of 36 inches for that same space. Another difference is the depth of the working space. Table 110.26(A) has varying depths from 3 to 5 feet, while Table 110.34(A) has depths ranging from 3 to 12 feet. All these distances are dependent on the specific condition and nominal voltage to ground. So, for example, for a high-voltage switchgear operating at 13,200 volts to ground, with grounded parts on the opposite side, the depth of working space would be 6 feet, measured from the front of the enclosure or exposed live parts. You will notice that higher voltages and higher hazard conditions require a greater depth of working space for worker safety. Section 110.27 covers the guarding of live parts under 1,000 volts, which in my previous blog could be considered a locked electrical room. For voltages over 1,000 volts, nominal, 110.31, Enclosures for Electrical Installations, would address the electrical room or enclosure for those installations. Some methods of enclosure could be: ·       An electrical vault ·       Electrical room or closet ·       A specific area surrounded by a wall, screen, or fence These methods are designed and constructed according to the nature and degree of hazard associated with the installation. Additional protective measures are required for installations involving walls, screens, or fences that are used to deter access by unqualified persons. These measures may include additional height or barbed wire. These requirements are different from those found in 110.26 and 110.27. Typically, the electrical room or vault access doors are locked to prevent access by unqualified persons, or those doors must be under continuous observation. The doors to these areas are required to open in the direction of egress and be equipped with panic hardware or listed fire exit hardware that opens upon simple pressure. For installations over 1,000 volts, nominal, these locked or monitored rooms, enclosures, or vaults must have a warning sign on the door reading, “DANGER – HIGH VOLTAGE – KEEP OUT.” This sign must also comply with the provisions outlined in 110.21(B) around their durability to withstand exposure to the environment and specific marking requirements. Section 110.27(C) also requires a warning sign for installations of 1,000 volts or less, where there are exposed live parts. It must be placed on the door but is only required to be marked to forbid unqualified persons to enter the electrical room or other guarded area. The wording for the warning sign outside of spaces with over 1,000 volts is much stronger because of the potential exposure to high-voltage electrical hazards. Any exposed live parts adjacent to the electrical room, vault, or enclosure entrance must be suitably guarded. Other exposed parts may require additional means to prevent inadvertent contact with exposed live parts, such as screens, partitions, or fences within the electrical room. Any exposed live parts above the working space are required to be elevated at the distances found in Table 110.34(E) and have permanent ladders for access according to 110.33(B). These codes around working space and electrical rooms are for the protection of qualified persons who may be working on or in this equipment. Stay tuned to NFPA Today for Part 3 in this blog series titled Electrical Rooms, where we will explore electrical vaults. We will look at their construction and some of the requirements for electrical equipment being installed in them.  

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.
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