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Great Power, Great resPonsibility

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ContentsGreat Power, Great ResponsibilityClick here p. 3

Heat, Load, & SpaceClick here p. 9

Small Labels, Big Safety MessageClick here p. 13

New NEC 240.87 Requirements Focus on Arc FlashClick here p. 15

Take Precautions Against Ground FaultsClick here p. 17

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Significant changes to NFPA 70E since 2012 compel updated electrical safety trainingBy Sheila Kennedy, Plant Services contributing editor, and Dee Jones, P.E., AVO engineering division manager

NFPA 70E: Standard for Electrical Safety in the Work-place® is an indispensable work in progress. For more than 35 years, NFPA 70E has delivered on its mission to create safer workplaces through improved electrical safety prac-tices, but the standard continues to evolve.

Approximately every three years, NFPA 70E is updated to incorporate the latest in electrical safety research, risk assessments, work practices, design considerations, and personal protective equipment (PPE) in an effort to reduce the number of deaths and injuries caused by shock, arc flash, and arc blast. This voluntary how-to guide to assist in Occu-pational Safety and Health Administration (OSHA) compli-ance can play an invaluable role in helping plants mitigate their electrical hazards, protect workers, promote safety requirements, and keep their facilities up and running.

Much is learned every year. When the National Fire Protection Association (NFPA) initiated the voluntary standard at OSHA’s request in 1979, the first edition ad-dressed only electrical installation requirements related to electrical safety. It wasn’t until the 1995 edition that arc flash hazards were addressed, and numerous workplace safety requirements have since been added.

As the safety standard evolves, so must the companies

and electrical workers who use it. The 10th and latest release, NFPA 70E 2015, contains some significant differences from its 2012 predecessor. It is essen-tial to understand these changes and why they matter in order to remain compliant with OSHA, avoid risking lives, reduce liability, and prevent unexpected and costly downtime.

SummAry OF NFPA 70E 2015 ChANgESThe new edition strives to ensure a safer workplace and clarifies the responsibilities of employees and employers by making the following major changes, in addition to exten-sive minor adjustments:• “Risk assessment” replaces the phrase “hazard analysis”

throughout the standard as part of an effort to make us-ers more aware of the devastating risk of failure and loss caused by shock, arc flash, and arc blast hazards. Specifi-cally, the “risk assessment process” now is defined as including identification of shock, arc flash, and arc blast hazards; estimation of the potential severity of injury or

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damage to health; estimation of the likelihood of injury occurrence or damage to health; and determination of whether protective measures and PPE are required.

• Maintenance status is now an integral part of the risk assessment.

• The electrical safety program must now include mainte-nance on electrical equipment as a primary element.

• Clarification was made that a comprehensive risk assessment, not just an incident energy analysis, is required (see sidebar on best practices for conducting a risk assessment and incident energy analysis).

• The responsibility for proper installation and mainte-nance is assigned to the equipment owner or the owner’s designated representative.

• The short-circuit current and clearing time of the over-current protective device must be known for an incident energy analysis.

• Hazard/risk category (HRC) tables have been replaced with new hazard identification tables and PPE category tables. All references to HRC have been replaced with the term “arc flash PPE category.” This will force a culture change because HRC has become institutionalized termi-nology in the industry.

• To use the PPE category tables, the short-circuit current and clearing time of the over-current protective device must be known.

• HRC 0, the standard PPE worn every day for normal con-struction activities, has been eliminated; now, the qualified person must make a risk assessment based upon normal operation of equipment that meets all of the following criteria:• The equipment is properly

installed• The equipment is properly

maintained• All equipment doors are closed and secured• All equipment covers are in place and secured• There is no evidence of impending failure

• Companies can develop their own PPE numbering system. • Warning label content was modified to include:

• Incident energy at a corresponding distance or PPE category selected using 70E tables, but not both

• Site-specific level of PPE• Labels must be updated when a hazard risk assessment

review renders the label to be inaccurate• It’s clarified that the electrical equipment owner is now

responsible for the documentation, installation, and main-tenance of field-installed labels.

• The requirements for construction and maintenance work were separated from outdoor work to enhance usability.

An arc flash occurs when electric current passes through the air instead of along its intended path. The result is extremely high heat that can cause severe burns, blind-ing light, and an explosion that can result in hearing dam-age and potentially fatal injury. Multiple arc flash incidents occur every day in workplaces across the United States.

There’s urgency to completing arc flash risk assessments and shock risk assessments: According to changes made for NFPA 70E 2015, these assessments must be conducted before any person is exposed to electrical hazards. The risk of an arc flash explosion occurring at your facility is not negligible, and the trend of increased power use combined with aging electrical infrastructure across the U.S. height-ens the danger. The Electrical Power Research Institute (EPRI) estimates direct and indirect costs to an employer from a fatal electrical accident in the millions of dollars.

Navigating all of the requirements, conditions, and ex-ceptions that result from these assessments requires a great familiarity with the new standard. Specifically, NFPA 70E 2015 Section 130.4 requires that a shock risk assessment be performed before beginning ener-gized work, and NFPA 70E 2015 Section 130.5 requires that an arc flash risk assessment be performed to:

1. Determine whether an arc flash hazard exists2. If a hazard exists A. Determine appropriate safety-related work practices B. The arc flash boundary C. The PPE to be used

In the end, OSHA will enforce compliance, including the requirement that an arc flash fisk assessment be per-formed. The costs of an electrical accident would vary by location, but without exception, it would be far more expen-sive to allow one arc flash accident to occur than it would be to prevent it. The following steps will help ensure that your arc flash risk assessments going forward will comply with both OSHA requirements and NFPA 70E 2015.

PreParation and biddinG

Developing, documenting, training, and implementing safety programs and procedures can be expedited with the aid of third-party experts in electrical safety and associated regula-tions and standards. An arc flash incident energy analysis is a complex project, and you may need to solicit bids from multiple providers. Note when you’re putting together a re-quest for proposal that it’s important for all bidders to bid on the same deliverables. Lower-cost bids may have items added after the study is done to complete a thorough analysis.

Best Practices for Conducting an Arc Flash Risk Assessment Study

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• The table update for restricted-approach boundary dimen-sions added clarity.

• A new requirement covers risk assessment associated with battery work.

• The prohibited-approach shock boundary was eliminated.

why DO thESE ChANgES mAttEr?NFPA 70E provides instructions on how to comply with OSHA’s electrical safety regulations. According to OSHA, there are approximately 350 electrical-related fatalities each year. OSHA is able to cite companies for noncompliance, with the consensus standard as a reference, when an electri-cal accident causes a serious injury or death, even though NFPA 70E is voluntary rather than a federal regulation. Cer-tain states and industries with more-restrictive occupational health and safety laws require NFPA 70E compliance.

NFPA makes it the responsibility of the employer to educate employees, including qualified and unqualified elec-trical workers, on safety standards. In fact, a plant manager can be held criminally responsible for a worker’s injury if the worker did not have proper safety training. Personnel in any industry who work on or around or who or interact with electrical equipment, AC or DC voltages of 50 volts or more,

An arc flash incident energy analysis is still the founda-tion upon which an accurate risk assessment is built. Once you have the incident energy analysis, you can complete your risk assessment and provide proper PPE and work prac-tices for your workers. It is always a good idea to request samples of an arc flash incident energy analysis report from each potential service provider. While this report is based on technical data, you need to ensure that the report uses language and formatting that relevant personnel will eas-ily understand. Also, ensure that the company performing the analysis adheres to a standardized process in perform-ing every arc flash incident energy analysis. This correlates with IEEE Standard 1584, Chapter 4 and IEEE 1584.1. The entire project also should be performed under the supervision of a registered professional engineer (PE).

A standard analysis will apply to three-phase equip-ment rated 240 volts or greater and three-phase equipment rated lower than 240 volts when served from a transformer 125 kva and larger. You will need to determine whether you want an expanded scope that includes 208 volt three-phase equipment served from a smaller-than-125-kva transformer or DC equipment rated 50 volts or higher.

DAtA COllECtiONBefore beginning the actual study, hold a proj-ect meeting (via conference call or on-site) with all personnel who will be involved to es-

tablish roles, responsibilities, and the plan for data gather-ing. Qualified staff must gather data from all applicable electrical equipment. Required information includes:• Data from the utility, including available fault cur-

rent, operating voltage, and specifics regarding the util-ity’s protective equipment at the point of service

• Specifics for each protective device in the electrical sys-tem, including manufacturer, model, available time/current settings, and short-circuit interrupting rating

• Transformer impedance, tap settings, and ratings• Conductor specifics, including lengths, sizes, and

types of all overhead lines, bus ducts, and cables

POwEr SyStEm mODEliNgOne-line diagrams must be developed or up-dated to show the current configuration and modes of operation for the power system. Ac-

curate electrical system drawings are necessary to identify power sources, voltage levels, electrical equipment, and protective devices. If you already have one-line diagrams, update the data and work from them, if possible. SKM Power Tools for Windows®, ETAP®, and other available engineering software is commonly used in the modeling.

Best Practices for Conducting an Arc Flash Risk Assessment Study (Continued)

riSK ASSESSmENtThe new standard’s risk assessment process broadens the scope of employees who must receive electrical safety education.

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2STEP

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or are responsible for safety in the workplace, must receive electrical safety training according to NFPA 70E 2015.

The new standard’s risk assessment process broadens the scope of employees who must receive electrical safety education. Employers must assess generally recognized arc flash and shock hazards in the workplace and provide protection from those hazards, and all employees must be made aware of the potential hazards. Safety consulting and engineering services can be called upon to help expedite and refine safety education and compliance initiatives.

The 2015 edition also requires an arc flash risk assessment to determine whether an arc flash hazard exists. Even the process of establishing an electrically safe work condition puts the employee at risk. If an arc flash hazard exists, the employer must determine the risk to employees and the required safe work practices, arc flash boundary, and PPE. Similarly, shock risk assessments are required to determine the voltage, shock boundaries, and PPE. Employees must be trained in these new skills, and must quickly implement them. The practice of hiring an engineering firm to perform an arc flash incident energy analysis now must be followed up with a risk assessment.

All employees who are exposed to electrical hazards

ShOrt-CirCuit StuDyA short-circuit study is required to determine the magnitude of current flowing through the power sys-tem at critical points at various time intervals after

a “fault” occurs. These calculations will be used to determine the bolted fault current, which is essential for the calculation of incident energy and interrupting ratings of your equipment. Comparison of equipment ratings with calculated short circuit and operating conditions will identify underrated equipment.

PrOtECtiVE DEViCE COOrDiNAtiON A protective device coordination should be per-formed to ensure that selection and arrange-ment of protective devices limits the effects

of an overcurrent situation to the smallest area. Results will be used to make suggestions for mitigation of arc flash haz-ards. Although this is an optional study, arc flash mitiga-tion cannot be performed without completing this step. It is recommended that this study be performed in accor-dance with IEEE Std. 242-2001 (i.e., the Buff Book).

ArC FlASh CAlCulAtiONSThese calculations are based on available short-circuit current, protective device clear-ing time, and distance from the arc. Calcula-

tions of incident energy levels and flash protection bound-aries will be completed for all relevant equipment busses and system configurations. The magnitude of arc hazards is determined using methods from NFPA 70E, IEEE 1584, or NESC Tables 410-1 and 410-2, as applicable.

rEPOrtiNgUpon completion of the calculations, generate and review the arc flash report. Your analysis provider will supply this report to you for a short review

period during which your team can assess mitigation recom-mendations. At this point, hold a management summary meeting to interpret the report results. Upon approval, a final report and full-size one-line diagrams stamped by a registered PE are required. It’s a good idea to get this report in a digital format.

lABEl iNStAllAtiON Arc flash warning labels should be generated. These labels identify incident energy and work-ing distance, nominal system voltage, and the arc

flash boundary. In addition to standard requirements, make sure the labels also include limited and restricted approach boundaries, date, upstream protective device, and recom-mended personal protection equipment. Bolted fault current may be included if desired. Make sure your labels comply with NFPA 70E 130.5(C), NEC 110.16 and ANSI Z535.

Best Practices for Conducting an Arc Flash Risk Assessment Study (Continued)

EFFECtiVE trAiNiNgEveryone must be trained to identify, understand, and avoid the electrical hazards and risk of injury associated with the tasks that they are required to perform.

3STEP

4STEP5STEP

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where the risk has not been reduced to a safe level (with no exposed energized conductors or parts of equipment and the equipment is essentially stagnant) require risk and avoidance training, according to the new standard, from electricians and operators to mechanics, janitors, office workers, or anyone who may plug into an electrical outlet. In order to train employees to identify, under-stand, and avoid the electrical hazards and risk of injury

associated with the tasks that they are required to per-form, it is recommended that a job/task analysis and task hazard analysis with shock and arc f lash risk assessments be conducted for each employee. The exposure or poten-tial exposure to electrical hazards should be recorded in the employee’s job description and their training require-ments determined accordingly.

Finally, employers must document that the hazard assessments were performed and authorize energized electrical work permits as needed. Companies must be prepared to share these records if requested during an OSHA inspection.

COmPliANCE mAy NECESSitAtE OutSiDE ASSiStANCEOSHA requires employers to document and implement an electrical safety program that addresses exposure to all existing hazards and those likely to exist in the workplace. The program must be published and available to all employ-ees who might be exposed to the hazards. OSHA also has specific equipment labeling requirements.

Unfortunately, the language used by OSHA can make its electrical standards difficult to interpret and apply. Train-ing on each new edition of the OSHA, NFPA 70E, and NEC electrical standards should be delivered by someone who has a thorough understanding of the latest requirements and how they apply to individual facilities and who can relay the complicated material in an easily understood manner. Third-party electrical safety experts can support hazard assessments, incident energy analysis, and follow-up activity speedily and in accordance with NFPA and IEEE standards.

Multiple delivery options are available for electricalsafety training. Custom courses can be designed to match a company’s industry and environment, including its voltage, energy level, and circuit equipment conditions. Online and

on-site training options avoid incurring personnel travel time and expenses. Fully equipped, regional training centers provide skills-based training combined with hands-on labs.

Arc flash and power system analysis studies performed by registered engineering firms identify and mitigate the haz-ards created by electrical equipment and systems. Folding these engineering studies into the latest industry standards enables continuous improvement of workplace safety, OSHA compliance, equipment reliability, and uptime.

Contributing Editor Sheila Kennedy is managing director of Additive Communications. Contact her at Sheila@addcomm.com.

Dee Jones, P.E., is engineering division manager at AVO training institute (www.avotraining.com). he has more than 30 years of experience in the electric utility

industry and has taught engineering practices and procedures for utility engineers and managers. he has conducted arc flash hazard analysis since 2009, and his experience conducting power system analyses includes short-circuit, load-flow, and protective-device coordination and transient motor starting. he holds a B.S. in electrical engineering and is a registered professional engineer in multiple states. Contact him at dee.jones@avoeedivision.com.

NFPA 70E 2015 Training Objectives • Identify the common factors of electrical accidents• Understand the arrangement of the NFPA 70E material• Explain the hazards of electrical work and their effects• Describe the main elements in an electrically safe

work program• Identify the requirements for establishing an

electrically safe work condition (lockout/tagout)• Identify the requirements for a shock risk assessment • Identify the requirements for an arc flash risk

assessment• Establish approach boundaries for

shock protection for qualified and unqualified employees

• Select PPE for shock protection• Select safe work practices if an

arc flash hazard is present• Understand the use of the arc

flash boundary• Select PPE for arc flash protection• Explain contractor and employer

compliance responsibilities

The elimination of hazard/risk categories will force a culture change because HRC has become institutionalized terminology.

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growth is something that every company, regardless of industry sector, counts among its goals. Increased revenue, greater market presence, and the prestige of leading an in-dustry are appealing to most organizations, so the incentives for growth are strong.

However, as most industrial facilities struggle to maxi-mize production and increase efficiencies, the addition of new electrical equipment can work to their detriment. This kind of growth – increased loads on existing electrical apparatus, and the addition of new apparatus to existing electrical infrastructure – can have deleterious effects on many aspects of equipment reliability.

This article explores how equipment expansion, when not properly tracked and managed, can negatively affect overall equipment health, personnel safety, and ultimately, a facility’s bottom line. Problems can take the form of power quality issues, increased ambient temperature in equipment rooms, or disruption to the work/rest cycle of maintenance and reliability team members.

turNiNg uP thE hEAtA physical condition known as thoracic outlet syndrome affects mainly the upper limbs of a person’s body and can result from physical overtraining. It’s characterized by inflammation in the shoulders and arms and can produce both pain and numbness.

In athletes, it’s commonly understood to be the result of too much of a good thing and can be remedied by a more con-trolled approach to a person’s workout goals.

This condition is a good metaphor for almost any other type of otherwise positive growth, including in industrial facilities where the goals can include meeting more aggressive produc-tion schedules, increasing throughput, and increasing pro-ductivity in the same space, all of which can lead to less than optimum equipment conditions. If the conditions are recog-nized and corrected in a timely fashion, long-term damage can be avoided. However, when equipment conditions are ignored and growth is not managed safely and effectively, the negative outcomes can be quite serious – even life-threatening.

Let’s look at electrical load first. The National Electric Code (NEC) gives guidance on what typically is referred to as the “80% rule.” This rule states that for continuous duty, which is defined in NEC Article 100 as maximum current for longer than three hours, a circuit fed from a single source should not exceed 80% of the capacity of the circuit. So, for a 20-amp circuit, 16 amps of continuous duty should not be exceeded. Having spent the greater part of our adult lives performing various types of electrical predictive mainte-nance (PdM) services, we can say that this rule is broken as often as it is followed. What may not be as readily apparent is the risk of operating under these conditions.

hEAt, lOAD, & SPACEManage the effect of growth on electrical equipment reliability and safety

By Dave Sirmans, CMRP, and TJ Garten, Allied Reliability Group

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Perhaps you’ve heard of the joule effect? Heat generated in a circuit or conductor is a product of the resistance of the cir-cuit and the current through the circuit. The amount of heat energy generated goes up as current (i.e., load) increases, and it increases at the square of the current. This phenomenon often is expressed as the equation P=I2R, with P being power (in the form of heat).

What is often not understood by otherwise conscientious electrical professionals is that electrical resistance is a product of temperature. As the circuit load increases, the amount of heat generated in the circuit increases. That heating causes a rise in electrical resistance in electrical components subjected to the increase in ambient temperature where the circuit in question or the larger electrical system component is located.

Most electrical apparatus are rated according to an expected ambient air temperature in the environment where the apparatus is installed. When an electrical space is occupied by numerous electrical apparatus, heat is already being generated under normal loading conditions. What then is the impact when load is added because of growth? New equipment needs to be fed from somewhere, right? We have an electrical room right there, and there is space in the panels, so the problem is solved, right? Wrong. We may have just caused a problem rather than found a solution.

It’s like the old joke about not being out of money because you’ve still got checks in your checkbook. Just because there are open circuit-breaker slots in a panel does not mean that capacity is available to accommodate the added equipment. Once we start to over-duty circuits, more heat is gener-ated. NEC Table 310.15(B)(16) gives allowable ampacities of insulated conductors and includes temperature withstand ratings for the various types of commonly used insulation. The caveat here, and it is mentioned in the table, is that these figures are based on an ambient temperature of 30ºC (86ºF).

Just for the sake of clarity, let’s define ambient tempera-ture. Merriam-Webster defines it as “interface temperature between a surface and the fluid medium surrounding that surface.” To be technically accurate, “ambient temperature” is not always synonymous with “room temperature” unless, of course, the electrical apparatus is in the open air of the room. Usually, electrical apparatus is inside of an enclosure, and there is typically a difference in temperature between the room where that enclosure is found and the temperature inside of the enclosure. The temperature inside of the enclo-sure should be considered the ambient temperature for any electrical components internal to that enclosure.

Having said that, the addition of electrical equipment to an existing electrical architecture will drive up both the de-vice ambient temperature and the overall room temperature.

This thermal impact must be considered not only for how it affects equipment but also for how it affects personnel. We’ll explore that further in a moment.

whErE ArE yOu grOwiNg?Another potential impact of electrical growth is on space. The added equipment has to go somewhere, and as men-tioned earlier, just because there is available space doesn’t mean that equipment should necessarily be installed there. NEC Article 110.26 discusses the spacing requirements for electrical equipment. Many folks are aware of the 36-inch rule for clearance in front of electrical enclosures. How many places have you been in where yellow and black striped tape on the floor indicates that particular boundary? And why do these boundaries exist?

Simply put, as stated in Article 110.26 of the NEC, they exist “to permit ready and safe operation and maintenance of such equipment.” Further in this article are some very specific guidelines for the width, height, and depth of the “working space.” One such rule regarding working width states that the working space must permit “at least 90-de-gree opening of equipment doors or hinged panels.” When we begin to overcrowd electrical spaces, we may restrict movement of covers, encroach on working spaces, and begin to negatively impact the egress from the working area, which is another consideration of equipment spacing discussed in Article 110.26.

KEEPiNg yOur PEOPlE SAFEThe cumulative effects of electrical growth now should be clear. The thermal impact is that more current means more heat. The spacing impact is that more equipment means less working space. These conditions can negatively affect person-nel, as well. And while some of the potential harms might be easy to recognize, others may not be.

Thermal impact is the most obvious of these: Fatigue lev-els increase in high-temperature, high-humidity environ-ments. This is exacerbated for qualified electrical person-nel because of the application of arc flash-rated personal protective equipment (PPE). The purpose of arc flash-rated

when an electrical space is occupied by numerous electrical apparatus, heat is already being generated under normal loading conditions. what then is the impact when load is added because of growth?

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PPE is to protect personnel from the risk of burn injury in the event of the release of energy from an arcing fault in electrical apparatus. The level of PPE a worker must wear is driven by the amount of potential energy present at each point along the electrical distribution path. In some instances, the PPE required for maintenance tasks can be cumbersome. Level 3 PPE requires a flash suit hood, 25 calories per cm2 full body coverage, gloves, and leather shoes, so imagine how much more heat stress an employee adorned in this level of PPE would be subjected to in a very short period of time.

OSHA offers guidelines for work/rest intervals for PPE application in high-temperature, high-humidity areas. For ambient temperatures higher than 90ºF, the work/rest cycle is 20 minutes of work followed by 20 minutes of rest. In an uptempo maintenance environment, though, we’d be willing to bet that this guideline is often not followed. The result is increased risk to the employee of heat-related injury. This can be multiplied in an environment where additional equipment and the associated increase in area ambient is overloading any conditioned space measures.

Less obvious is the overall electrical safety danger that re-sults from overcrowding electrical rooms and production ar-eas with added equipment. There is a provision in the Insti-tute of Electrical and Electronics Engineers (IEEE) Standard 1584, Guide for Performing Arc Flash Hazard Calculations, that allows the over-current protective device clearing time to be limited to two seconds for incident energy calculations. The “two-second rule,” as it is known, is often applied for electrical apparatus with a higher than two-second clear-ing time when it can be reasonably expected that a qualified electrical worker could egress the area of the arcing fault in two seconds or less. This guideline is widely applied when using only the clearing time causes incident energy calcula-tions to be restrictively high.

Imagine an instance wherein a maintenance electrician is interfacing with a device for which, unbeknownst to him, the two-second rule has been applied. Then, in the event of an arcing fault, he is subjected to higher energy exposure than he is protected against because egress from the area of the fault is inhibited by equipment overcrowding. In such a case, the qualified electrical person would be applying PPE in accor-dance with the label when that PPE level was reached with an expectation that the apparatus in question would continue to have adequate working space to allow egress.

Finally, there is the potential impact of added equipment draining maintenance resources because of their mere presence. The maintenance plans, preventive maintenance schedules, and PdM routes in many facilities are based on

an equipment count arrived at from a walkdown performed at some point in the past. As equipment is added, the device counts obviously increase. Many maintenance programs allocate resources based on the number of items on the maintenance plan. If the additional required electrical devices aren’t accounted for, scope increases without the ability to track and measure the impact. Thus, an effort to do more with less is thwarted because there isn’t enough time to maintain every device in the facility.

SO NOw whAt?The good news is that any of the aforementioned circum-stances can be discovered and ultimately repaired. To use the thoracic outlet syndrome example, an orthopedic medi-cal professional with an understanding of sports medicine can provide advice on how an individual can meet exercise and physical growth goals in a slow, controlled, and man-ageable fashion.

The cure to equipment growth woes is out there, too, and skilled resources can help you recognize the trouble spots in your facility. Align your maintenance program with skilled providers of reliability engineering, planning, and schedul-ing methodologies who adhere to industry best practice standards, and your growth can be safer, more productive, and much less painful than the alternative.

Dave Sirmans is an electrical subject matter expert with Allied reliability group (www.alliedreliabilitygroup.com). he provides clients with reliability engineering

support with regard to electrical equipment, technologies, and applications; he also assesses, designs, and implements preven-tive maintenance and predictive maintenance and reliability continuous improvement programs and offers mentoring services. Contact him at sirmansd@alliedreliability.com.

tJ garten is an electrical subject matter expert with Allied reliability group. he helps develop standards, procedures, and advanced analyses for electrical training

deliverables in the areas of motor circuit, infrared, ultrasound, power quality and energy efficiency/management testing. Contact him at gartent@alliedreliability.com.

the temperature inside of the enclosure should be considered the ambient temperature for any electrical components internal to that enclosure.

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Complying with the require-ments of NFPA 70E®, the National Fire Protection Association’s Standard for Electrical Safety in the Workplace, is a multi-faceted process and is the respon-sibility of the facility owner.

An arc-flash risk assessment is required for any electrical equip-ment operating at 50V or greater that may require inspections, adjustment, servicing, or maintenance while en-ergized. Equipment that falls into this category is required to have the field marking (label) in place.

An assessment also required even if it is a company’s practice to work only on de-energized equipment. Why? Be-cause until the circuit is verified dead, it is considered energized. To approach the circuit to test it, the worker must be outfitted in the appropriate level of personal protective equipment (PPE); this level is specified on the label.

Arc-flash labeling requirements were first introduced in the National Electrical Code® (NEC®) in 2002 and subsequently appeared in NFPA 70E in 2009. While both standards require arc-flash labels, there are some differ-ences in their specific requirements.

NEC lABEliNg rEquirEmENtSNEC Section 110.16 requires label-ing that provides a general warning against arc-flash hazards. Changes to the NEC labeling standard have been made with subsequent revision cycles (2005, 2008, 2011, and 2014). NEC labels should contain “signal” words, colors, and symbols and should com-ply with ANSI Z535, which has been adopted by OSHA. Messaging should include specific details on:• The nature of the hazard

• The consequences of the hazard• Avoidance procedures

NEC labeling requirements also are referenced in Section 110.21(B). Because NEC labels do not contain circuit-specific information, they can be either field- or factory-applied.

NFPA 70E lABEliNg rEquirEmENtSNFPA 70E labels provide detailed, site-specific information on the arc-flash hazard present; this is useful for PPE selection. NFPA 70E labeling require-ments, found in Section 130.5(D) of the standard, state that equipment that is likely to be examined, adjusted, serviced, or maintained while energized shall be field-marked with a label con-taining all of the following information:1) At least one of the following:

• Available incident energy or re-quired PPE category

• Minimum arc rating of clothing• Site-specific level of PPE

2) Nominal system voltage3) Arc-flash boundary

As a recommended best practice, consider adding information such as date, calculation method, references to standards, an engineering contact, and shock boundary information.

NFPA 70E lABEliNg OPtiONSNFPA 70E-2015 Section 130.5(D) gives facilities choices in ways to commu-nicate the incident energy level and/or required PPE. Whichever labeling option a facility selects, consistency in using it is key.

1. Minimum Arc Rating of ClothingThis option potentially allows for development of a simplified arc-flash PPE approach in the facility.

For example, consider the PPE system defined in NFPA 70E, Annex H, where arc-rated clothing recom-mendations are provided for locations that have available incident energy less than 1.2 cal/cm2, between 1.2 and 12 cal/cm2, and between 12 and 40 cal/cm2. Under such a system, a worker at a location with a calculated incident energy level of 4.5 cal/cm2 would wear clothing rated for up to 12 cal/cm2.

When utilizing this approach, work-ers in some cases might have to wear more PPE than would be absolutely necessary, as there could be arc-rated clothing available that exceeded the actual incident energy level but that did not meet the defined minimum arc rating. The advantages of such a system include:• Simplified arc-flash PPE system

using a standardized two- or three-level PPE approach.

• Increased efficiency and fewer errors

SmAll lABElS, Big SAFEty mESSAgElearn what you need to do to comply with the latest NFPA 70E safety labeling rulesby Antony Parsons, Schneider Electric Engineering Services

HAZARD OF ELECTRICSHOCK, EXPLOSION,OR ARC FLASH

• Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E

• This equipment must only be installed and serviced by qualified electrical personnel.

• Turn off all power supplying this equipment before working on or inside equipment.

• Always use a property rated voltage sensing device to confirm power is off.

• Replace all devices, doors and covers before turning on power to this equipment.

Failure to follow these instructions will result in death or serious injury.

Figure 1. Example “Danger” label meeting NEC requirements.

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in label application, thanks to the use of fewer unique labels.Finally, because the actual incident energy levels are not

shown at each location but are essentially “rounded up” to the next-higher standard value, minor changes in the system would not invalidate the labels nearly as often as they otherwise might. For example, if a change in the utility system meant that the calculated 4.5 cal/cm2 incident energy value rose to 5.2 cal/cm2, the same 12 cal/cm2 minimum arc rating would still apply.

Arc Flash informationuse this information in accordance with applicable OShA standards, NFPA 70E-2015 and other required safe electrical work practices.

12 cal/cm2 Incident Energy at a Working Distance of 1 ft 6 in. 4 ft 9 in. Arc Flash Boundary

208 V Shock hazard when cover is open 3 ft 6 in. Limited Approach 1 ft 0 in. Restricted Approach

q2C: 12345678 Date: 09/10/14

Values produced by a Schneider Electric engineering analysis. Any system modification, adjustment of protective device settings, or failure to properly maintain equipment will invalidated this label.

For more information, contact Schneider Electric at 1-888-778-2733. Copyright 2014 Schneider Electric. All rights reserved.

Figure 2. Example “Arc Flash Information” label meeting NFPA 70E requirements, and showing minimum arc rating of clothing.

2. Available Incident Energy or Arc Flash PPE CategoryWith this option, the equipment is labeled with either the available incident energy level calculated in an arc-flash study or PPE category determined using NFPA 70E Tables.

3. Site-specific level of PPENFPA 70E also allows for labels to show required “site-specif-

ic” levels of PPE. Site-specific levels are not defined in NFPA 70E but are intended to be developed by end users who wish to implement a site-specific PPE system to ensure that:• The labels they affix to their equipment are consistent with

their overall Electrical Safety Program and worker training, or• The labels define specific PPE requirements for the facility.

A site-specific label also could be used to closely match “legacy” labels generated under previous versions of NFPA 70E. Though NFPA 70E does not provide further guidance on defining the site-specific options, Schneider Electric recommends that any such labels align with the facility’s written Electrical Safety Program and that workers be trained to read, interpret, and properly apply the informa-tion contained on the labels.

Arc Flash informationPPE LEVEL - Site-Specific

2use this information in accordance with applicable

OShA standards, NFPA 70E-2015 and other required safe electrical work practices.

8 cal/cm2 Incident Energy at a Working Distance of 1 ft 6 in. 4 ft 9 in. Arc Flash Boundary

208 V Shock hazard when cover is open 3 ft 6 in. Limited Approach 1 ft 0 in. Restricted Approach

q2C: 1234578 Date 12/01/14

Values produced by a Schneider Electric engineering analysis. Any system modification, adjustment of protective device settings, or failure to properly maintain equipment will invalidated this label.

For more information, contact Schneider Electric at 1-888-778-2733. Copyright 2014 Schneider Electric. All rights reserved.

Figure 4. Example “Arc Flash Information” label meeting NFPA 70E requirements, and showing site-specific information.

It is critical that the labeling approach, the employee train-ing program, and the Electrical Safe Work Practices policy and documentation all align. The ultimate goal of arc-flash labeling is to allow a qualified employee to correctly under-stand, interpret and apply the information on the arc-flash labels. Schneider Electric’s current practice is to provide two labels – the “Danger” label to comply with NEC, along with the NFPA 70E “Arc Flash Information” label. Together, the two labels constitute an effective labeling system that meets the requirements of both standards.

Antony Parsons is a senior staff engineer for Schneider Electric Engineering Services. he earned a BSEE from the university of houston, and an mS and PhD in electrical engineering from the university of texas at Austin. he has 15 years’ industry experience, and is a member the iEEE

P1584 working group on Arc Flash hazard Calculations.

Arc Flash informationuse this information in accordance with applicable OShA standards, NFPA 70E-2015 and other required safe electrical work practices.

1.71 cal/cm2 Incident Energy at a Working Distance of 1 ft 6 in. 1 ft 10 in. Arc Flash Boundary

208 V Shock hazard when cover is open 3 ft 6 in. Limited Approach 1 ft 0 in. Restricted Approach

Eqpt Name: l1A q2C: 12345678 Date: 09/10/14

Values produced by a Schneider Electric engineering analysis. Any system modification, adjustment of protective device settings, or failure to properly maintain equipment will invalidated this label.

For more information, contact Schneider Electric at 1-888-778-2733. Copyright 2014 Schneider Electric. All rights reserved.

Figure 3. Example “Arc Flash Information” label meeting NFPA 70E requirements, and showing available incident energy.

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Arc flash relay devices simplify meeting the new requirements while providing important additional safeguards for people and equipment

By Alex Kalinski, P.E., littelfuse

the National Electrical Code continues to evolve in the direction of arc flash protection. Plant managers who want to be compliant need to know what the changes mean. For-tunately, the rewording of a key paragraph will likely make compliance easier, and will better protect electrical workers.

The NEC changed the name of paragraph 240.87 from Non-Instantaneous Trip in the 2011 edition to Arc Energy Reduction in the 2014 edition. As explained in the 2014 NEC Handbook, the changes to this section remove the mention of “instantaneous trip setting” from the criteria for applying this requirement. Instead, an instantaneous trip is now required where the highest continuous current trip setting in a circuit breaker is rated or can be adjusted to 1200 A or higher.

More importantly, the revision to Section 240.87 allows for a new method that can make the job of compliance a good deal easier: deploying an energy-reducing arc-flash mitigation system (or an approved equivalent means).

2011 NEC SECtiON 240.87 Paragraph 240.87 of the 2011 edition of the NEC stated that whenever a circuit breaker was used with a rating of 1200 A or higher (or one that could be adjusted to 1200 A or higher) and which did not have an instantaneous trip func-tion, one of the following technologies also was required

to be deployed in order to provide secondary protection: 1) zone-selective interlocking, 2) differential relaying, or 3) an energy-reducing maintenance switch with local status indicator. Let’s look at each of the alternatives allowed by the 2011 standard.

Zone-selective interlocking involves interconnecting downstream and upstream circuit breakers so that if a short circuit or ground fault occurs on a branch circuit, the breaker feeding it will trip instantaneously, and simultane-ously send a signal to the breaker just upstream, telling the upstream breaker to use its time-delay function instead of tripping instantaneously. This is important because other-wise a downstream short or ground fault could draw enough current to cause both breakers to trip instantaneously, kill-ing power to branch circuits other than to the circuit with the fault.

Zone-selective interlocking provides an instantaneous response to a high value fault, which protects equipment and workers faster than would a circuit breaker without instantaneous trip. However, a high resistance arc flash may not draw enough current to trip either breaker, potentially resulting in injury, damage, and downtime.

Differential relaying uses current transformers at the in-puts and outputs of the electrical equipment being protected (zones); when a fault occurs, the zone in which the input and

NEw NEC 240.87 rEquirEmENtS FOCuS

ON ArC FlASh

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output currents do not match is the location of the fault, and the appropriate breaker is tripped. Again, this provides fast protection, but differential relaying is complicated, expen-sive, and consumes a fair amount of space.

An energy-reducing maintenance switch manually sets the current pickup lower and the time delay faster to trip the breaker feeding a panel as fast as possible while someone is working on it; if there is an arc flash, the breaker should trip instantaneously and limit the energy delivered. This rapid response provides protection and may even reduce the level of PPE that workers must wear before approaching the panel. The drawback of this approach is that it depends on human beings: workers must manually activate the switch before beginning maintenance, and remember to deactivate it afterward to prevent nuisance tripping or miscoordina-tion. Also, this approach does not provide protection when maintenance is not being performed.

2014 uPDAtE imPrOVES PErSONNEl PrOtECtiONIn 2014 the NEC was rewritten to widen the set of options available to plant managers for complying with Section 240.87, including the use of an arc flash relay.

An arc-flash relay (Figure 1) is a device that detects the light emitted as an arc flash begins and sends an instanta-neous trip signal to the breaker feeding the affected panel or enclosure, which stops the arc and minimizes the danger

by reducing the incident energy. The use of an arc flash relay can greatly reduce the potential for arc-flash injury to per-sonnel and damage to equipment, and also may reduce the level of PPE required to work on the panel.

Arc flash relays are compact and easy to retrofit into existing electrical panels: mount light sensors, connect them to the relay, and connect the relay output to the trip input of the existing circuit breaker. Some relays are essentially plug-and-play; more sophisticated relays require moderate configuration via PC for zone control, delay settings, and in-cident history. One helpful feature is LED indication on the relay and sensors that the system is working; if the system is not blinking, then workers know to close the cabinet.

So far, 36 states have adopted the 2014 edition of the NEC, and inspectors are citing plants that do not comply with the revision of paragraph 240.87. Arc flash relays are simple and inexpensive to retrofit, and they provide a new way for managers to become compliant with the NEC while also providing improved protection for workers.

Alex Kalinski is a regional Sales Engineer for littelfuse (www.littelfuse.com), based out of Atlanta, gA. he is a licensed Professional Engi-neer in the State of georgia, and has nine years of experience in the field of electrical power. he can be reached at akalinski@littelfuse.com.

Figure 1. Arc-flash relays send a trip signal to the circuit breaker in <1 ms.

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www.PLANTSERVICES.ComElectrical Safety

tAKE PrECAutiONS AgAiNSt grOuND

FAultS

Preventing workplace accidents, injuries, and deaths is everyone’s business. Despite some notable im-provements in workplace incident rates, fatalities occur frequently, with over 4,300 workplace deaths reported in 2012, according to the Electrical Safety Foundation Inter-national (ESFI).

Electrical accidents are a leading cause of these on-the-job injuries and deaths. Between 1992 and 2010, an average of 268 people annually died on the job from electrocution. Thousands more suffered injuries such as shocks and burns from electrical accidents. Electrical safety violations are major cause of these accidents, which in addition to the human cost have a major economic impact on employers in the form of financial penalties, medical and disability expenses, and insurance rate hikes.

Electrical risks exist in varying degrees in many differ-ent industries, including construction, manufacturing, utility, transportation, agriculture, mining, oil and gas,

food and beverage, and chemical processing. The risks result from workers performing routine jobs that require using high-power electrical equipment in harsh, wet, or hazardous conditions.

These risks include improper connections and any unprotected electrical connections that are exposed to moisture, metals, and harsh conditions, which can cause

Electrical safety violations are major cause of these accidents, which in addition to the human cost have a major economic impact on employers in the form of financial penalties, medical and disability expenses, and insurance rate hikes.

gFCi-compliant electrical systems help protect workers from a potentially lethal combination of moisture, metals, and harsh conditions By tony quebbemann, molex

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power f low interruptions. Improper work processes and uses of equipment can also cause accidents, ranging from nuisance tripping to short circuits to major malfunc-tions. For example, employees can inadvertently cause electrical mishaps by taking shortcuts to complete tasks more rapidly.

Creating safer workplaces requires rigorous enforce-ment of electrical safety codes and guidelines. The National Fire Protection Association (NFPA) publishes advisory guidelines intended to safeguard people and property from electrical hazards. Industrial companies and their workers must follow Occupational Safety and Health Administration (OSHA) regulations for workplace safety and health. NEC guidelines and OSHA regulations dovetail on key points.

To protect workers, electrical equipment should be kept free from hazards that can result in dangerous condi-tions, injuries or fatalities. The combination of water and electricity is potentially lethal, and can occur through a ground fault—an unintentional electrical path between a power source and a grounded surface.

How can these ground faults occur? Current leakage takes place when an electrical tool is damaged or becomes wet, causing current to flow outside the circuit conductors. Severe shock, burns, or electrocution can occur if a person gets in the path of the current.

As a result, the use of ground fault protection in in-dustrial settings is vital. Ground fault circuit interrupter (GFCI) devices quickly trip electrical circuits when they detect ground faults or leakage currents. GFCI technology saves lives by preventing accidental electrocutions. GFCI-compliant devices can ensure protection is in place even if workers circumvent safety protocols.

NFPA NEC guidelines and OSHA regulations are critical to specifying these GFCI-compliant devices. For example, extension cords used with portable electric tools need to be 3-wire and employ hard or extra-hard rated usage cable. That means power cords designed for typi-cal residential applications—which can be easily crimped, bent, or broken under heavy foot traffic or rolling equip-ment on a plant floor—are not appropriate. Instead, rugged industrial cords constructed of thicker, heavy gauge wire and insulation must be used. Additionally, cords should not exceed 100 feet in length to prevent nuisance tripping and other accidents.

Likewise, electrical boxes must be properly installed and rigidly supported. Both NEC guidelines and OSHA requirements require adequate strain relief for cables entering junction boxes, cabinets or fittings and other

openings to protect workers from accidental contact with conductors.

To ensure proper installation, many companies follow NEMA ratings and IP standards for watertight receptacles, connectors, and other components used in wet locations

or exposed to gas, fumes, vapors, or harsh chemicals. For example, electrical components require watertight connec-tions to eliminate or reduce risk of electrical shocks, short circuits, and electrical fires. Flip-lid protection prevents moisture from penetrating power outlets. Also, duplex receptacles should be equipped with a separate flip-lid over each outlet to prevent moisture from penetrating an unused outlet when the other is in use.

Finally, companies should take advantage of the latest technology to better protect their workers. New integrat-ed electrical solutions are raising the bar on workplace safety and GFCI compliance, such as wet-location wiring systems that are uniquely designed for industrial applica-tions at outdoor worksites or a plant f loor, where process-ing equipment requires frequent high-pressure wash-downs. These integrated, scalable systems can include outlet boxes, coverplates, cordsets, plugs, connectors, and receptacles.

Keeping workers safe is the right thing to do and a good business decision. A wide range of surprisingly economical, high-performance, GFCI-compliant devices are available for portable power, new installations, and after-market equipment upgrades in today’s industrial plants and worksites.

tony quebbemann is global product market-ing manager for molex (www.molex.com), and has worked in the electrical industry for 30 years with positions in sales and marketing within companies comprised of manufacturing,

distribution and contracting. he holds an undergraduate degree in mechanical Engineering from the university of illinois and an mBA from the university of Chicago. he can be contacted at tony.quebbemann@molex.com.

the combination of water and electricity is potentially lethal, and can occur through a ground fault—an unintentional electrical path between a power source and a grounded surface.

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Littelfuse AF0500 and PGR-8800 Arc-Flash RelaysAn arc-flash relay is an integral component of an arc-flash protection scheme that can minimize damage and save money, time, and lives. A minimal investment of just a few thousand dollars can save tremen-dous costs in lost equipment, downtime and production, not to mention the risk of employee injury or fatality. A proactive strategy is recommended when it comes to protecting critical assets and employee safety. Click below for more information on the Littelfuse AF0500 and PGR-8800 Arc-Flash Relays.

Application Brief: Woodhead® Watertite® Wet-Location Wiring SolutionsMolex knows electrical safety is crucial to any jobsite. That’s why Molex is setting a new safety standard with the Woodhead® Watertite® Wet-Location Wiring Safety System. The industry’s first fully integrated wiring safety solution offers best-in-class ground fault circuit interrupter (GFCI) protection with flexibility and ruggedness for a variety of environments. Learn more in the application brief.

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