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Without properly performing an E3MP, incident energy levels can drastically increase above calculated values, which may go unnoticed until a life-changing event occurs.

More and more companies today are taking the smart step toward performing an arc flash analysis on their electrical distribution system to determine arc flash hazard levels and accurately post the hazard level on associated equipment. However, once the study is completed, most firms never give it another thought — assuming the arc flash calculations will always accurately reflect the hazard in the field.

After the analysis is complete, there is no reason to second-guess the engineer who performed the calculations. But the reality is, over time, the calculated arc flash hazard values are in jeopardy of becoming erroneous if the equipment is not part of an effective electrical equipment maintenance program (E3MP).

Arc flash severity variables

Three primary variables are required for the calculations associated with an arc flash analysis: available fault current, distance from the fault, and duration of the fault. Distance from the fault is determined by IEEE Standard 1584, “Guide for Performing Arc Flash Hazard Calculations,” and the fault current is a property of the electrical distribution system being evaluated. Fault duration is the variable that can be inadvertently impacted by a company’s electrical maintenance strategy. Fault duration is the characteristic of the arc flash event, which is determined by the upstream overcurrent protective device’s (OCPD’s) ability to interrupt the fault. For the purpose of an analysis, the engineer assumes the OCPD will interrupt the fault in the manner and speed at which it was designed.

Arc Flash 0218 2

A lack of maintenance could lead to a dangerous situation, where an electrical worker is insufficiently protected from the arc flash energy levels produced during a fault.

Circuit breakers are one of the most common OCPDs and are considered as time-limiting equipment in the arc flash analysis. However, the time required for a circuit breaker to interrupt a fault can be dramatically impacted by the lack of proper maintenance. In order to better understand the relationship between circuit breaker maintenance and arc flash severity, you must first understand some basics related to circuit breaker design and operation.

What is a circuit breaker?

A circuit breaker is a switching device that can be operated manually or automatically for control and protection of an electrical power system. From a protection standpoint, circuit breakers are devices that automatically stop current from flowing if a certain abnormality in the system is detected — in simple terms, it interrupts the flow of current in the circuit.

There are two main types of circuit breakers: magnetic and thermal. Magnetic circuit breakers respond quickly to short-duration large overcurrent faults, while thermal circuit breakers respond best to long-duration small overcurrent faults. In addition, a thermal-magnetic circuit breaker combines the advantages of both types, breaking circuits in response to both large overcurrent and prolonged small overcurrent conditions. Magnetic circuit breakers are more relative to the arc flash discussion in that they are typically the breakers responsible for clearing short-duration large overcurrent faults that involve arc flash events.

Magnetic circuit breakers rely on induction through a coil of wire called a solenoid. When current flows through the solenoid, a magnetic field is created. This field exerts a force on a nearby magnet; the larger the current, the stronger the force. If the current is strong enough, the magnet is pushed out of the solenoid with enough force to trip the mechanism that breaks the circuit. This is useful if there is a sudden surge in current, because the force created by the solenoid increases proportionally with the amount of current, allowing a rapid response for fault interruption.

Why circuit breaker maintenance is crucial

Arc Flash 0218 3

A circuit breaker is a mechanical device, so inherently it has components that are required to move in order for a successful operation. When calculating incident energy levels, the engineer would use information from the manufacturer with regard to how quickly those mechanisms work together to complete the operation and interrupt the circuit. Each breaker is designed to interrupt fault current based on its time-current characteristics curve. These design characteristics are used in the arc flash analysis calculations to determine the fault clearing time.

Notice the impact increased fault clearing time has on incident energy levels.

If an E3MP is not utilized on a breaker, then the operating times provided by the manufacturer become irrelevant. Circuit breaker mechanisms will start to malfunction (contacts can start to stick and grease can begin to “gum up”). Even worse, the breaker might not work at all. A delay in response time might not seem like much, but it only takes milliseconds for the incident energy on a typical 480V motor starter to go from negligible to deadly.

Impact of increased fault clearing time

The Figure shows arc flash values for a typical 480V motor starter breaker in a system with 3kA of available fault current. The y-axis is the arc flash energy level in cal/cm2. Time is shown along the x-axis starting at 2 msec up to a maximum of 2 sec. Notice how quickly the incident energy level rises.

Let’s assume the breaker is designed to clear the fault in three cycles. The calculation for this example results in an incident energy level of 2.2 cal/cm2, which would require a minimum of Category 1 personal protective equipment (PPE). If the lack of proper maintenance causes the breaker to not clear the fault until 30 cycles (0.5 sec), the incident energy level reaches 22.2 cal/cm2. This would require a minimum of Category 3 PPE. The significance of this time delay is that the electrician wearing typical Category 2 “daily wear” PPE would be insufficiently protected from the arc flash energy levels produced during the fault, regardless of what the warning sticker on the equipment states as the required PPE.

Conclusion

Even if a company has the most accurate and detailed arc flash analysis performed on its system and provides employees with top-of-the-line PPE, there is still a safety-related responsibility for the establishment of an E3MP. If the company does not incorporate an E3MP on all OCPDs, then employees remain at risk of being injured due to the probability of arc flash events that exceed calculated values. Without an E3MP, the probability is higher that the operating speeds of the mechanical parts in your breakers are significantly slower than designed, and, as demonstrated in the example above, it takes only fractions of a second to defeat all of the efforts associated with an effective arc flash mitigation program.

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See the origial article at: http://www.ecmweb.com/arc-flash/how-improper-maintenance-can-increase-arc-flash-severity?NL=ECM-06&Issue=ECM-06_20180213_ECM-06_853&sfvc4enews=42&cl=article_3_b&utm_rid=CPG04000000918978&utm_campaign=18559&utm_medium=email&elq2=a8857a985fd14639aa724cfc8bec0026

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Installations of smart meters have more than doubled since 2010, per the Dec. 7, 2017 EIA report, while slower growth is the norm for demand response and energy efficiency

According to recently-released EIA data, almost half of all U.S. electricity customer accounts now have smart meters. By the end of 2016, U.S. electric utilities had installed about 71 million advanced metering infrastructure (AMI) smart meters, covering 47% of the 150 million electricity customers in the United States.

In contrast to two-way AMI, the second-largest category of meters is one-way Advanced Metering Infrastructure (AMR), a category for which meter installations peaked in 2012 at 48 million units installed. The total AMR population of meters nationwide over last four years has wavered between 46 and 47 million total units.

Link electric use 1

Advanced Metering Infrastructure (AMI)

Chart1

Chart2

Smart meters have two-way communication capability between electric utilities and customers. One-way meter-to-utility communication, also known as automated meter reading (AMR), was more prevalent before 2013. Since then, two-way AMI smart meter installations have been more common based on data collected in EIA’s annual electric utility surveys.

Two-way AMI meters allow utilities and customers to interact to support smart consumption applications using real-time or near real-time electricity data. Smart meters can support demand response and distributed generation, improve reliability, and provide information that consumers can use to save money by managing their use of electricity.

AMI data provide utilities with detailed outage information in the event of a storm or other system disruption, helping utilities restore service to customers more quickly and reducing the overall length of electric system outages.

While the EIA data has shown a healthy growth rate for AMI, equaling about 10% a year, the EIA data on uptake of demand response programs continues to show low or no growth, with total enrolled customers hovering just over 9 million as shown below:

Chart4

The EIA Annual Electric Outlook just released on Dec 7, 2017 is at this link: https://www.eia.gov/electricity/annual/pdf/epa.pdf

 

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See the origial article at: http://www.theenergytimes.com/new-energy-customer/us-electric-utility-customer-base-now-exceeds-150-million

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BICSI

The publication includes new standards, codes, and best practices.

BICSI, the association advancing the information and communications technology (ICT) community, has published a new edition of the Outside Plant Design Reference Manual (OSPDRM).

Written by OSP subject matter experts, the manual focuses on outside plant properties, with the detailed information contained applicable to all projects large and small. In addition to covering traditional infrastructure subjects such as cabling and pathways, the OSPDRM also covers items not typically found within interior design work, such as right-of-way, permitting and service restoration.

The 6th Edition of OSPDRM includes updates and additional information on:

• Passive optical networks (PON)

• Aerial installation of all dielectric self-supporting cable (ADSS)

• Maintenance and restoration of OSP

• Radio frequency over glass (RFoG) specific to OSP fiber optic installations

• Additional excavation methods for direct-buried cable and pathways (i.e., vacuum, hydro-vac, and air nozzle)

• New storm loading requirements for aerial OSP design that includes the U.S. Warm Islands Zone per requirements in 2017 NESC

• Updated OM5 optical fiber cable type

• Project management information and geographic information systems (GIS)

• Air-assisted cable installation for OSP cable runs

• Changes resulting from the issuance of the 2017 edition of the NESC concerning clearances and grounding/bonding requirements

More information on the OSPDRM, 6th edition, can be found here.

 

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See the origial article at: http://www.ecmweb.com/training/new-addition-bicsi-s-outside-plant-design-reference-manual-released

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A properly designed and executed job safety plan gives workers a practical tool to help ensure they make it home safely every day.

Planning for safety isn’t new to the electrical trade. Guidelines to conduct a job hazard analysis (JHA) for each individual job were first published by OSHA in 1989, and have since been regularly revised. However, complying with the 2018 edition of NFPA 70E “Standard for Electrical Safety in the Workplace” requires the completion of an in-depth “job safety plan,” probably in more detail than what most employers and electrical workers may conduct today.

Job Safety Planning 1
Job safety planning requires inspection of this transfer switch prior to performing maintenance. In addition to recording information from the arc flash warning label, the worker inspects the condition of the equipment to ensure it is suitable for normal operation.

Some workplaces use generic forms, often referred to as a job safety analysis (JSA), for identifying hazards and determining methods to mitigate those hazards. Whether referred to as a JSA, JHA, or other company-specific term, the objective is the same: Provide a structured method for workers to recognize hazards and identify the choices they will make to protect themselves from those hazards.

New NFPA 70E requirements

The 2018 edition of NFPA 70E contains new requirements for the worker to analyze the critical steps of the electrical job, assess the electrical hazards associated with those steps, and then determine how they will protect themselves. Prior to this edition of the standard, there was no requirement for workers to perform such a detailed risk assessment. This new requirement for a job safety plan must also be reviewed as part of the required job briefing. Should a change in work scope occur during the course of the job, the job safety plan must be revised as needed, and an additional job briefing must occur to reflect any change. Remember, the purpose of the job safety plan is to have the qualified electrical worker review each step of the job they are to perform, determine how safe it is to perform that particular task, and what actions are needed to ensure they will be protected.

OSHA Part 1926 “Safety and Health Regulations for Construction” requires the person in charge of the job to conduct a job briefing. Rules for job briefings have appeared in NFPA 70E since 1995. However, there is no reasonable assurance that the properly conducted job briefing itself will identify all electrical hazards. To ensure hazards are properly addressed, the job safety plan requires:

  • The employee in charge, who must also be a “qualified person,” is responsible to complete the job safety plan and job briefing.
  • The job safety plan must be documented.
  • The plan must include both a “shock risk assessment” and an “arc flash risk assessment.”
  • The plan must identify work procedures involved, special precautions to be taken, and the energy source controls for the equipment undergoing work.

Both shock risk assessments and arc flash risk assessments require the electrical hazards be identified and the likelihood of the occurrence and potential severity of any potential injury be considered. Once this information regarding the hazards is identified, any specific protective measures needed are determined. As expected, the assessments must be documented.

Completing the job safety plan

NFPA 70E doesn’t specify an exact type of job safety plan form be used for documentation. It is expected that companies will review and modify (as applicable) their own JSA, JHA, or similar documents used to plan work. The key points of the document is that each critical step of the job is analyzed for electrical hazards, and logical decisions are made to protect workers based on items such as use of work procedures, PPE, or other special precautions. In some cases, it may be identified that a particular step may not be completed safely at all, and other means, such as lockout/tagout must be used.

Informative Annex F Risk Assessment and Risk Control has been expanded for the 2018 edition of NFPA 70E to help companies and workers with the process of risk assessment. While different methods of job safety planning are mentioned, the concept of using a “risk assessment matrix” is typical for many organizations. A basic example of such a matrix is provided in the Annex. For a risk assessment matrix that assigns a risk code to each critical step see the Sample Risk Code Matrix.

Drawbacks

Workers who do not normally complete such detailed job safety plans may object to the complexity of the new requirements. It can be argued that determining the likelihood of an occurrence, or the potential severity of an injury, is subjective. Routine tasks are just that — routine, and should not require any special planning.

There is always a learning curve to any new process. Job safety plans can be streamlined for many jobs. Individual work steps should already be incorporated as part of a standard work or maintenance procedure. But when it comes to routine work, warning flags should go up. Human performance studies indicate such work can be more dangerous than tasks performed less often.

There’s a reason for proper job safety planning. Electrical accidents may not occur as often as other types of incidents, but they have much higher fatality rates. They typically happen in a fraction of a second, and the results can be disabling injuries/fatalities. Thinking about the job to be performed, what could go wrong, and how to best protect oneself before the job begins are effective methods of reducing risks to workers.

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See the origial article at: http://www.ecmweb.com/safety/job-safety-planning-and-2018-nfpa-70e

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solar tech

  • Advanced Energy Economy Institute (AEE Institute) has issued a new report focused on cybersecurity challenges on a distributed grid, identifying key hurdles and best practices the group says state and federal policy makers will need to address to ensure a secure power system.
  • Among the recommendations is the development of a short list of "mandatory and standardized requirements" that could be implemented at little to no expense, and for cybersecurity to be embedded as part of standard security practices impacting manufacturers.
  • The utility industry has stepped up its focus on cybersecurity in recent years as threats have become more sophisticated and persistent. This month, two new widespread cybersecurity vulnerabilities have been identified, with solar inverters in particular at possible risk.

Securing the electric grid is a complicated challenge that becomes even more difficult as more resources are connected and the system becomes increasingly reliant on flows of data.

Lisa Frantzis, a senior vice president at Advanced Energy Economy, said the industry must prepare for "new vulnerabilities" as the grid evolves.

“As we transition to more advanced and intelligent technologies that improve our energy system and benefit customers, we must take into account and prepare for new vulnerabilities to the security of our nation’s energy infrastructure,” Frantzis said in a statement announcing the new report.

The paper focuses on several areas, including: cybersecurity threats to the economy and energy sector; best practices for a distributed, intelligent grid; cybersecurity policy and regulatory frameworks at the state and national level; and protective measures and protocols for grid operators.

According to the report, cybersecurity for grid-edge devices creates new challenges, in part due to their limited capabilities. Such devices are "high in number and limited in bandwidth, memory, and storage space," the report notes. "As a result, standard industry solutions for other technology areas such as malware protection, file integrity monitoring, firewalls, and whitelisting, have not been viable for edge devices."

Network infrastructure has also had similar limitations, AEE added. Kenneth Lotterhos, managing director of energy at Navigant Consulting, said in a statement that recent events show that the level of cyber threats is "increasing and targeting a broader range of assets, including advanced distributed energy technologies and smart grid applications."

Specialized applications for edge devices and critical network infrastructure have been developed in the past, the report notes, "but they have not been widely adopted." While some of that has been related to cost and complexity, AEE Institute also says that until recently there has been a perception that the threat was relatively low.

That perception has changed significantly in recent years, and cybersecurity is now a major focus of the industry.

A 2015 attack on Ukraine resulted in widespread power outages, serving as a wakeup call. Last summer, cybersecurity firm Dragos issued a report concluding the malware used in that attack could be modified by developers to target the United States.

The newest vulnerabilities identified, possibly impacting solar inverters, are known as Spectre and Meltdown, and leverage processing techniques known as speculative execution and caching, in order to access data that should be off limits.

One problem thus far, however, is that patches to address the vulnerability are significantly slowing down operating systems. The features Spectre and Meltdown attack were created to speed up computer processors, and plugging the leak has resulted in performance slowdowns of up to 30%.

P3 strives to bring you quality relevant industry related news.

See the origial article at: https://www.utilitydive.com/news/aee-grid-edge-technologies-vulnerable-to-cyber-threats/515138/

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