Topic: Electrical

New Checklist Helps Electricians Assess Whether Damaged Electrical Systems Should be Repaired or Replaced After a Natural Disaster

The past few months have produced a number of powerful and damaging natural disasters across the US. From earthquakes and wildfires in the west to tornadoes in the Midwest and hurricanes across our northern and southern states, no one part of the country has been immune to the mighty force of nature. In the midst of this trying time, and with the worst of the hurricane season still to come (hurricane season runs from June to November), building owners and managers of industrial and commercial facilities are facing (and will continue to face) the daunting process of disaster recovery. More specifically, when electrical systems are damaged in a natural (and yes, even man-made ones, too!) disaster, electricians need to make a critical decision about whether the electrical equipment that was damaged can be salvaged or not. So where to start? Let NFPA lend a hand. We've created a new checklist for electricians to help highlight and simplify key aspects of this decision-making process. The checklist builds off of recommendations in Chapter 32 of NFPA 70B, Recommended Practice for Electrical Equipment Maintenance* (2019 edition). The checklist includes such things as: A list of disaster scenarios, which can inflict damage of varying degrees to facilities Steps for assessing equipment A Priority Assessment Table Steps to help identify factors for replacement or repair … and more. Still, even with the help of the checklist, the choice between repair and replace will not always be an easy one. Following these simple suggestions can be the difference, however, between an impossible task and an informed decision. Before your community experiences a disaster, download this free “Natural Disaster Electrical Equipment Checklist” and review the contents. Having this information at your fingertips will be extremely valuable should your community call on you for your electrical experience and assistance in the aftermath of a storm or other weather-related event.   Additional disaster-related resources can be found on NFPA's disaster webpage, including tip sheets, related code information, articles, and more. *The complete current edition of NFPA 70B and related resources are available for free access or to purchase at www.nfpa.org/70B.

Mapping the Codes for Solar Photovoltaic (PV) Systems

The installation of a solar photovoltaic (PV) system is an increasingly attractive way to reduce the cost and environmental impact of producing and using electrical energy. However, these systems can also have an impact on safety for building occupants, electrical workers, and emergency responders. As more homes and businesses are fitted with PV systems, it is important to understand that multiple codes and standards across different disciplines must be applied to ensure a safe installation for all. Whether you are a system installer, property owner, or electrical inspector, finding all of the applicable requirements can be a bit like looking for buried treasure. In this blog post, I'll save you some digging and give you a map! Reference #1 - NFPA 70®, National Electrical Code® (NEC®), 2020 edition establishes requirements for the safe use of electricity and electrical equipment by reducing or eliminating hazards, such as electric shock and fire. The following articles address PV systems as noted and either apply or modify the requirements found in the first four chapters of the Code: Article 690 addresses PV systems other than the PV generating plant (solar farms) covered in Article 691. Article 691 addresses large-scale systems with an inverter generating capacity of 5000 kW and greater. Article 705 addresses installation of one or more electric power production sources operating in parallel with a primary source(s) of electricity. Most jurisdictions adopt the NEC into law, as there are few alternative codes for electrical installation. Reference #2 - NFPA 1, Fire Code, 2018 edition prescribes minimum requirements necessary to establish a reasonable level of safety and protection from fire, explosion, and dangerous conditions. Part of this code's objective is to ensure that firefighters can respond effectively and safely to a fire. PV systems are a concern for firefighters because, during a fire, roof-mounted PV systems can impede access to the roof or become a potential shock hazard. Where PV systems are installed on the ground, vegetation and near-by structures could provide a means of spreading fire, and the PV panels could become a shock hazard for anyone with access to the array(s). The following sections address these concerns: Section 11.12.2 addresses roof-mounted systems and establishes requirements for marking and roof access. Section 11.12.3 addresses ground-mounted systems and establishes requirements for clear space, vegetation management, and security. Where the International Fire Code® (IFC®) is adopted instead of NFPA 1, similar requirements can be found in Section 1204 of the 2018 edition. Reference #3 - NFPA 5000, Building Construction and Safety Code, 2018 edition provides minimum regulations for the safety of buildings and structures. The following section ensures that roof-mounted PV systems are securely supported by the building and mounting equipment: Section 38.12 addresses roof-mounted systems and establishes requirements for mounting and support, wind design, and seismic design. Where the International Building Code® (IBC®) is adopted, similar requirements can be found in Section 3111 of the 2018 edition. Where the International Residential Code® (IRC®) is adopted, similar requirements for one- and two-family dwellings can be found in Section 324 of the 2018 edition. Reference #4 - NFPA 70B, Recommended Practice for Electrical Equipment Maintenance, 2019 edition outlines inspection and maintenance programs for industrial-type electrical systems and equipment. In order to reduce hazards due to failure or malfunction of the PV equipment, the recommendations of the following chapter should be followed: Chapter 33 addresses maintenance of PV systems. Similar recommendations can be found in CSA Z463-18, Guideline on maintenance of electrical systems. Additional References - PV systems are sometimes supplemented with a means to store the surplus energy produced during the day so that it can be used at night. Where a battery or energy storage system is installed, the following references apply to that portion of the system: NEC®, 2020 edition: Article 480 addresses battery storage systems Article 706 addresses energy storage systems >1kWh Chapter 52 of NFPA 1, 2018 edition or Section 1206 of the 2018 IFC® Where the IRC® is adopted for one- and two-family dwellings, Section 327 of the IRC® In addition to these references, a new standard, NFPA 855, Standard for the Installation of Stationary Energy Storage Systems, is currently being developed to address the hazards associated with energy storage systems. Note that the references I've mentioned in the paragraphs above are applicable to privately-owned systems and might not apply to systems that are under utility control. Before proceeding with any design or installation, it is prudent to verify which editions of these codes have been adopted in your jurisdiction and to check whether any local amendments have been incorporated as well. The NFPA CodeFinder tool can help you get started. On a final note, the documents I've identified can contain additional references that are either mandatory or simply helpful. I have chosen not to include those secondary references here. Use the comments section below to tell us about any references you think are particularly important or helpful for designing, installing, or maintaining PV systems. We look forward to hearing from you. Thanks for reading! NOTE: NFPA 70, National Electrical Code, and NEC are registered trademarks of the National Fire Protection Association. International Fire Code, IFC, International Building Code, IBC, International Residential Code, and IRC are registered trademarks of International Code Council, Inc.

A Better Understanding of NFPA 70E: Impending Equipment Failure

How do you know if equipment is ready to fail? What are signs of impending failure? Who should know what the signs of impending failure are for a piece of equipment? NFPA 70E®,Standard for Electrical Safety in the Workplace® requires that before you operate a piece of electrical equipment that you confirm that the normal operating conditions have been met. You are put at risk of injury if any one of those conditions is suspect. I have written several blogs covering the subject and the impending failure condition confuses many people. Typically the employer/owner is not aware of the daily condition of individual equipment in their facility. This means that the unqualified person operating the electrical equipment must be trained to recognize an impending failure since conditions can change on a daily basis. The electrical safety training provided should include recognizing potential failure modes and identifying signs of impending equipment failure. This is true whether the equipment that the employee operates is portable and cord-and-plug connected or a section of a large assembly line. However, the signs of impending failure vary greatly by the type of electrical equipment. <>The smell of ozone, presence of smoke, and sound of arcing are all possible indications of potential equipment failure. Damage or discoloration of the power cord could be a sign for the portable equipment. A tripped circuit breaker or operation of a ground-fault circuit-interrupter could be another sign. For the assembly line equipment there may be warning lights or alarms. A controller may shutdown to prevent damage and should not be routinely reset. Without proper training to understand such things the employee may not recognize the risk of an injury while operating the equipment. Electrical safety is not just for qualified persons and involves a lot more than donning PPE. Federal law mandates that an employer provide a workplace that is free from known hazards. An employee operating equipment that is exhibiting signs of impending failure is placed at risk of injury due to electrical hazards. It is only proper training that prevents an injury in that circumstance. Does your electrical safety training for unqualified persons include this important aspect? If you are the employee, do you know how to recognize a potential equipment failure that could prevent you from returning home today? Want to keep track of what is happening with the National Electrical Code® (NEC®)? Subscribe to the NEC Connect newsletter to stay informed of new content. The newsletter also includes NFPA 70E information such as my blogs. Next time: On July 16- 18, I will be in Indianapolis for the NFPA 70E meeting and the week after for the NFPA 72 meeting so this will be my only blog for the month of July. I will post something about that meeting in my August blog. Please Note: Any comments, suggested text changes, or technical issues related to NFPA Standards posted or raised in this communication are not submissions to the NFPA standards development process and therefore will not be considered by the technical committee(s) responsible for NFPA Standards development.  To learn how to participate in the NFPA standards development process and submit proposed text for consideration by the responsible technical committee(s), please go to www.nfpa.org/submitpi for instructions.
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Safeguarding Pool and Hot Tub Owners from the Hazards of Electricity

Summer is finally here! Drive through any neighborhood and it is nearly impossible to miss the signs. The smell of burgers on the grill and fresh cut grass permeates the landscape and perfectly accompanies the sound of children laughing and playing in backyards everywhere. And with summer, comes swimming. Whether it is swimming in a pool, lake, ocean, or even just playing in a puddle, children of all ages jump at the chance to head to water when the temperatures rise.  But before we do, it is important for all of us to take a moment and consider the safety measures that have been put in place to ensure that an epic cannonball off the diving board does not turn into a tragic electrical accident. In case you didn't know, submerging our bodies in water makes us more susceptible to electric shock and reduces resistance of our skin. This in turn permits lower voltage levels to cause a sufficient amount of current to flow through our bodies, which is extremely dangerous, and possibly even deadly. For this reason, NFPA 70®: National Electrical Code® (NEC®) contains many requirements to minimize shock hazards in and around pools and hot tubs and protect us from harm. With this in mind, there are essentially two methods of protection that are employed in the pool and hot tub safety requirements of the NEC®: Eliminate voltage gradients in the water and surrounding areas Interrupt power if and when there is a problem The first method of protection, eliminating voltage gradients, deals less with protection from faulty electrical equipment itself and more so with taking measures to electrically connect conductive surfaces and items in the area around the pool, including measures to bond the water itself to the conductive surfaces and equipment. This concept is referred to as "equipotential bonding," meaning, bonding things together in order to keep everything at the same or equal potential or voltage. The NEC requires all of the following to be bonded together with a minimum of an 8 AWG solid, copper conductor or with rigid metal conduit made of brass or other corrosion resistant material: Conductive pool shells, such as concrete poured or sprayed over rebar or a copper conductor grid Perimeter surfaces up to 3 feet measured horizontally from the inside wall of the pool Metal fittings Electrical equipment associated with the circulation system or pool cover Metallic components Fixed metal parts like ladders and handrails Underwater lighting Lastly, if none of these components to the system are in contact with the actual water itself, means must be provided to expose a minimum of 9 square inches of a corrosion-resistant and conductive material to the water. By connecting all of these items together, the chance that any one of them develops a difference in potential from any of the other items or the water itself is now reduced. The other main method for protecting people from electrical hazards in and around pools and hot tubs involves turning the power off when there is a fault or other problem. There are also two main vehicles in which this level of protection can be provided: An effective ground-fault current path to facilitate the opening of the overcurrent protective device (OCPD) Ground-fault circuit interrupter protection that monitors the current on the circuit and interrupts power when the difference between what goes out and comes back in exceeds 4-6 mA Combined, these two methods protect pool goers by removing the electricity from the environment when there is a problem. For instance, often the area surrounding a pool is very corrosive and harsh with respect to electrical equipment and can cause conductors to loosen up or break off from their terminals. This could lead to a conductor contacting the frame of a motor or a metal raceway or side of a box increasing the chances of someone being electrocuted. Having an effective ground-fault current path like an equipment grounding conductor will help the overcurrent protective device supplying the circuit open quickly by providing a low impedance pathway and spiking the fault current high above the trip setting or rating of the OCPD. For instances where a human might come in contact with this faulty equipment, GFCI protection is required. This protection helps to interrupt the power even when the fault current isn't high enough to trip the OCPD, which might be the case in the event that the EGC or bonding conductor has been broken or otherwise disconnected. All these measures are aimed at protecting us in an environment we often view as recreational and relaxing. However, due to the chemicals and moisture and nature of activities that take place in and around a pool, a certain level of maintenance and care must be done to ensure that these protective measure continue to function and provide the intended level of safety. This is where both qualified electricians and pool owners can work together. Regular testing of GFCI receptacles and circuit breakers is needed to verify that these devices will operate when the need arises. Regular inspection of grounding and bonding conductors is also a must to make sure that these needed pathways are still in place both to open the OCPD when equipment fails and to eliminate dangerous voltage gradients that could lead to electric shock drowning or electrocution. Staying safe in and around pools from electricity is often not the first thought on our minds when the temperature climbs and we head poolside to relax and unwind. But with a little attention to maintenance and inspection of the measures put in place at the time of installation, we can do that cannonball without a second thought.  So now that you're aware of how pools are built to protect you from electricity (even if you don't understand all of the requirements) remember to work together with a local qualified electrical who can help you with maintenance and inspections, and can answer any questions you may have. Then kick back and enjoy your time around the pool this summer knowing you've put safety first!  For additional pool safety tips, resources and information, check out NFPA's website.
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A better understanding of NFPA 70E: NFPA 70E audits

New equipment is added to a facility. Knowledge gained while working through an issue drives change in safety standards. Employees with different backgrounds and from different generations have dissimilar learning styles. Electrical safety is not a static field, it is more dynamic than often believed. How do you evaluate your electrical safety program? Training, procedures and practices involving electrical safety need to be periodically reviewed to not only stay current but to be effective. NFPA 70E®, Standard for Electrical Safety in the Workplace® contains many requirements which should be your starting point for auditing an electrical safety program (ESP). The first place NFPA 70E requires an evaluation of an ESP is in 110.1(F). Controls are the company's electrical safety metrics for determining if the ESP is effective and efficient. In order to evaluate a system, you need to know where you started and how far you have come. Metrics are measurable points to determine performance. They also can be used to determine if improvements to the safety program are required and, if so, what needs to be changed. There are two common metrics used to determine the effectiveness of something: lagging metrics and leading metrics. Lagging metrics provide a reactive view of a safety program. Leading metrics are used to identify and correct contributing factors before an incident occurs. A combination of these metrics can enhance a safe work program. Next in NFPA 70E, 110.1(K) covers necessary audits. Auditing and enforcement is a critical part of any electrical safety program. It is vital that the electrical safety program — as well as the auditing and enforcement actions — be documented for the benefit of the employees and of the company. The process control points and actions (i.e., the items capable of being measured) need to be determined for there to be effective auditing. An audit of the overall ESP (110.1(K)(1)) is necessary to ensure that program principles and procedures are kept current with changing situations. Section 110.1(K)(2) addresses field audits. This involves going into the field — wherever employees are performing their required tasks and there is the potential of exposure to electrical hazards — to gather information. It is important to watch employees perform their electrical safety related tasks and ensure that they are using PPE appropriate for the task to be performed. When it has been confirmed that the ESP principles or procedures are not being followed, corrective action must be taken. The field audit should be used to confirm that all electrical hazards are addressed, and to evaluate any program and physical conditions that have changed.  Lockout/tagout programs and procedures require auditing in 110.1(K)(3). The objective of the audit is to make sure that all requirements of the procedure are properly detailed and that employees are familiar with their responsibilities. The audit should determine whether the requirements contained in the procedure are sufficient to ensure that the electrical energy is satisfactorily controlled. The audit must ensure that the lockout/tagout procedure is effective and is being properly implemented. There are several other requirements for audits and supervision in NFPA 70E. Any audit should identify and correct deficiencies in the procedure, employee training, or enforcement. Corrective actions could consist of either modification of the training program or a revision to the procedures, such as increasing the frequency of training. Audits and metrics should measure program effectiveness as well as be used for developing program improvement. Audits should evaluate incidents to determine any necessary change to the ESP. An ESP should not be developed then placed on the shelf as a job well done. Electrical safety in the workplace is not the same as it was 10 years ago. How are you protecting employees with the best ESP possible? Next time: Is there a way to increase electrical safety for workers in the future. Please Note: Any comments, suggested text changes, or technical issues related to NFPA Standards posted or raised in this communication are not submissions to the NFPA standards development process and therefore will not be considered by the technical committee(s) responsible for NFPA Standards development. To learn how to participate in the NFPA standards development process and submit proposed text for consideration by the responsible technical committee(s), please go to www.nfpa.org/submitpi for instructions.
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