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 Post subject: 2015 NFPA 70E Changes
PostPosted: Fri Sep 12, 2014 7:38 am 
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The new 2015 Edition of NFPA 70E was released today. The following is an article that I wrote several months ago listing the major changes for the 2015 edition. It was originally published in the May 2014 issue of Electrical Contractor Magazine and is provided here as a resource for your use.

Change Is On The Way! 2015 NFPA 70E
Published: May 2014 - Electrical Contractor Magazine
By Jim Phillips


Deja vu?

Déjà vu is that feeling you get when you think you have seen or done something before. NFPA 70E is giving us all déjà vu since it was just three short years ago, in 2011, that we were analyzing changes for the upcoming 2012 edition (see “It’s Almost Here, ”May 2011 Electrical Contractor Magazine. It’s time for that feeling once again as we move toward completion of the 2015 edition.


What's new?

Some of the terminology used during this revision cycle has changed. Request for Proposals are now called Public Input (PI), and this revision cycle had 448 PIs. The Report on Proposals (ROP) is now called the First Draft, and what was previously called the Report on Comments (ROC) is referred to as the Second Draft.


The changes this article outlines are based on what was known at the time of writing. It does not include every change made, and much of the language is paraphrased due to space limitations. Since the NFPA Standards Council has not formally approved the final document, there is always the possibility of additional changes. Therefore, always refer to the final approved version when it is published.


Global changes

Several terms used throughout NFPA 70E have been changed for the 2015 edition. The left column in the terms table above refers to the term used in the 2012 edition and the right column lists the new corresponding term for 2015.


Please note: all references to hazard/risk category (HRC) have been deleted throughout the standard. Arc flash PPE category is the revised term.

Article 90 Introduction

90.2 Scope


90.2(A) Covered: The words “safety-related maintenance requirements, and other administrative controls” have been added to what is covered to emphasize the importance of maintenance.


90.2(B) Not Covered: The reference to “Installations underground in mines and self-propelled mobile surface mining machinery and its attendant electrical trailing cable” has been deleted from the not covered section, meaning it is now covered.


Article 100 Definitions

DELETED DEFINITIONS

Bare-hand work: This definition has been deleted.


Prohibited approach boundary: All references to the prohibited approach boundary have been deleted throughout the 2015 edition. Once the restricted approach boundary was crossed, there were no other requirements. 


REVISED DEFINITIONS

Restricted approach boundary: The word “risk” has been replaced by “likelihood.”


Incident energy: This definition now references thermal energy instead of just energy.


Qualified person: This definition changed from “one who has the skills and knowledge” to “one who has demonstrated the skills and knowledge.” Also the word “recognize” has been changed to “identify and avoid the hazards.”


NEW DEFINITIONS

Hazard: A source of possible injury or damage to health


Hazardous: Involving exposure to at least one hazard


Risk: Refers to a combination of both the likelihood of injury occurrence and the severity


Risk assessment: A process that identifies the hazards, estimates the potential severity of injury or damage to health, estimates the likelihood of the injury occurrence or damage to health, and determines if protective measures are required


Article 110 General Requirements for Electrical Safety-Related Work Practices

This article was reorganized by moving Section 110.3 Electrical Safety Program to 110.1 and moving 110.1 Relationships with Contractors (renamed Host and Contract Employers Responsibilities) to Section 110.3.


The order is now 110.1 Electrical Safety Program, 110.2 Training Requirements, and 110.3 Host and Contract Employers Responsibilities.


110.1 ELECTRICAL SAFETY PROGRAMS

110.1(A) General: The language “activity appropriate for the electrical hazards” has been changed to “activity appropriate to the risk associated with electrical hazards.”


110.1(B) Maintenance: This new addition states that “The electrical safety program shall include elements that consider condition of maintenance of electrical equipment and systems.” The addition of this new section means that subsequent sections are renumbered.


110.1(F) Electrical Safety Program Procedures: The reference to both the limited approach boundary and arc flash boundary has been deleted. New language emphasizes that “An electrical safety program shall identify the procedures to be utilized before work is started by employees exposed to an electrical hazard.”


110.1(G) Risk Assessment Procedure: The title was changed to align with the emphasis on risk assessment. The reference to limited approach boundary and arc flash boundary was deleted.


110.2 TRAINING REQUIREMENTS

110.2(A) Safety Training: New language was added to emphasize the element of risk. It reads, “when the risk associated with that hazard is not reduced to a safe level.”


110.2(C) Emergency Response Training: This section was renamed and subdivided into four parts.


(1) Contact Release: This section now requires annual refresher training.


(2) First Aid, Emergency Response and Resuscitation: New language now requires annual refresher training for cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED). This changed the existing language that required annual certification by the employer.


(3) Training Verification: New language requires that “Employers shall verify at least annually that employee training required by this section is current.”


(4) Documentation: “The employer shall document that the training required by this section has occurred.”


110.2(D)(1) Qualified Person


110.2 (D)(1)(b)(4): The decision-making process was converted to a list of four items that includes the following:


“i) Perform the job safety planning ii) Identify electrical hazards iii) Assess the associated risk iv) Select the appropriate risk control methods from the hierarchy of controls identified in 110.1(G) including selecting the personal protective equipment.”


110.2(D)(1)(e): The term “voltage detector” was replaced with “test instrument.”


110.2(E) Training Documentation


Informational Note No. 1: A new informational note states that the training content could be one or more of the following: the syllabus, curriculum outline, table of contents or training objectives.


110.3 HOST AND CONTRACT EMPLOYERS' RESPONSIBILITIES 


110.3: The title of this section was changed from “Relationships with Contractors.”


110.3(C) Documentation: New text was added to this section: “Where the host employer has knowledge of hazards covered by this standard that are related to the contract employer’s work,” there shall be a documented meeting between the host employer and the contract employer.


110.4 USE OF ELECTRICAL EQUIPMENT

110.4(C) Ground-Fault Interrupter (GFCI) Protection


(2) Maintenance and Construction: This new section states, “GFCI protection shall be provided for operating or using cord and plug connected tools related to maintenance and construction activity supplied by 125 volt, 15, 20, or 30 ampere circuits. Where employees operate or use equipment supplied by greater than 125 volt, 15, 20, or 30 ampere circuits either GFCI protection or an assured equipment grounding conductor program shall be implemented.”


Article 120 Establishing an Electrically Safe Work Condition


120.1 Verification of an Electrically Safe Work Condition: The title was changed from “Process of Achieving an Electrically Safe Work Condition.”


(5): The term “rated voltage detector” was changed to “rated test instrument” and “through verification on a known voltage source” was added to verify the test instrument is operating satisfactorily.


120.2(B) PRINCIPLES OF LOCKOUT/TAGOUT EXECUTION

120.2(B)(3) Retraining: Retraining shall be at intervals not exceeding three years. This rule has been added to the existing language, which also requires retraining when the procedure is revised.


120.2(B)(4) Training Documentation: This new addition requires documenting when each employee receives training required by this section. The documentation shall be made when the employee demonstrates proficiency in work practices involved, and the documentation shall contain the content of the training, the employee’s name and dates of the training.


120.2(E)(4)(e): Additional language was added regarding hold cards. Now a method of accounting for personnel who are working under the protection of the hold card must be included.


120.3(A) Temporary Protective Grounding Equipment: New text states that the location, sizing and application of temporary protective grounding equipment shall be identified as part of the employer’s job planning.


Article 130 Work Involving Electrical Hazards

130.1 General: New language clarifies what Article 130 covers, including the following:


1. When an electrically safe work condition must be established


2. The electrical safety-related work practices when an electrically safe work condition cannot be established


130.2(A)(4) Normal Operation: The word “interaction” can still cause some confusion regarding work practices. This new section states that normal operation of electric equipment shall be permitted where all of the following conditions regarding the equipment are satisfied:


1. The equipment is properly installed.


2. The equipment is properly maintained.


3. All equipment doors are closed and secured.


4. All equipment covers are in place and secured.


5. There is no evidence of impending failure.


130.2(B) ENERGIZED ELECTRICAL WORK PERMIT

130.2(B)(1) When Required: References to the limited approach and arc flash boundaries have been deleted, and the new language states, “When energized work is permitted in accordance with 130.2(A) an energized electrical work permit (EEWP) is required under the following conditions:


“(1) When work is performed within the restricted approach boundary or


“(2) When the employee interacts with the equipment when conductors or circuit parts are not exposed but an increased likelihood of injury from an exposure to an arc flash exists.”


130.2(B)(2) Elements of Work Permit: This section now requires the results of the shock risk assessment rather than shock hazard analysis and must include the voltage to which personnel will be exposed. “Arc flash hazard analysis” was changed to “arc flash risk assessment,” and the working distance must now be included if the incident energy is provided.


130.2(B)(3) Exemptions to Work Permit: This section was reworded and includes the following exceptions:


• Testing, troubleshooting and voltage measuring


• Thermography and visual inspection if the restricted approach boundary (RAB) is not crossed


• Access/egress from an area with energized electrical equipment with no electrical work and the RAB is not crossed


• General housekeeping and miscellaneous nonelectrical tasks if the RAB is not crossed.


130.4 ASSESSMENT AND APPROACH BOUNDARIES

130.4(A) Shock Risk Assessment: The title was changed from “Shock Hazard Analysis.”


Table 130.4(C)(a) Approach Boundaries to Energized Electrical Conductors: The prohibited approach boundary was deleted from the table. The second row was changed from 50V–300V to 50V–150V, and the third row was changed from 301V–750V to 151V–750V.


130.5 ARC FLASH RISK ASSESSMENT

The title was changed from “Arc Flash Hazard Analysis.” The arc flash risk assessment shall determine if the arc flash hazard exists. If it does, the risk assessment shall determine the appropriate safety-related work practices, the arc flash boundary and the personal protective equipment (PPE) to be used within the arc flash boundary.


Informational Note No.1: New language was added to this informational note that states: “Where equipment is not properly installed or properly maintained, PPE selection based upon incident energy analysis or the PPE category method may not provide adequate protection from arc flash hazards.”


130.5(A) Documentation: This new section requires the results of the arc flash risk assessment to be documented.


130.5(B) Arc Flash Boundary: In addition to the existing definition of the arc flash boundary being the distance where the incident energy equals 1.2 cal/cm2, new language has been added permitting the arc flash boundary to be determined by Table 130.7(C)(15)(A)(b) or Table 130.7(C)(15)(B) when the requirements of the tables apply.


130.5(C) Arc Flash PPE: New text emphasizes that only one method shall be used for selecting PPE at the same piece of equipment. These methods include either the results of an incident energy analysis or the arc flash PPE category method but not both. Language was also added to specifically prohibit using the results of an incident energy analysis to specify an arc flash PPE category in Table 130.7(C)(16).


130.5(D) Equipment Labeling: The arc flash labeling require-ments still include the nominal system voltage and arc flash boundary as in the past. However, new language further clarifies how to label the PPE requirements.


The revised language states at least one of the following:


•  Either the available incident energy with the corresponding working distance or the arc flash PPE category in Table 130.7(C)(15)(A)(b) or Table 130.7(C)(15)(B) shall be listed but not both.


•  Minimum arc rating of clothing.


•  Site-specific level of PPE.


This section now specifies that the owner of the electrical equipment is responsible for the documentation, installation and maintenance of the field-marked label.


130.7(C)(15) SELECTION OF PERSONAL PROTECTIVE EQUIPMENT (PPE) WHEN REQUIRED FOR VARIOUS TASKS


Table 130.7(C)(15)(A)(a) Arc Flash Hazard Identification for Alternating Current (AC) and Direct Current (DC) Systems: This new table is used for determining when arc flash PPE is required for both AC and DC electrical systems. The tables use a simple yes or no if arc flash PPE is required and are based on the task to be performed and the equipment condition. Equipment condition parameters include whether the equipment is properly installed and maintained, all equipment doors are closed and secured, covers are in place and secured, and there is evidence of impending failure.


New PPE Category Tables—General Comment: New tables have been developed based on the PPE category. The hazard/risk references have been deleted. Category 0 and the columns for rubber gloves and insulated tools have been deleted. Some of the arc flash boundaries have been rounded to the nearest foot.


Table 130.7(C)(15)(A)(b)—Arc Flash Hazard PPE Categories for Alternating Current (AC) Systems: This table defines the PPE categories for AC systems. Specific tasks have been deleted, and it now lists equipment, arc flash PPE category and the arc flash boundary.


Table 130.7(C)(15)(B)—Arc Flash Hazard PPE Categories for Direct Current (DC) Systems: This table defines the PPE categories for DC systems. Specific tasks have been deleted, and it now lists equipment, arc flash PPE category and the arc flash boundary.


130.7(D)(1) Insulated Tools and Equipment: This section now references the restricted approach boundary instead of the limited approach boundary and applies when working inside the restricted approach boundary of exposed energized electrical conductors or circuit parts where tools or handling equipment might make accidental contact.


130.7(E)(2) Barricades: This section now includes the arc flash boundary. Barricades shall be placed at the greater of the limited approach boundary or the arc flash boundary.


Chapter 2 Safety-Related Maintenance Requirements

Article 200 INTRODUCTION

200.1 Scope: Informational Note No. 3 now references IEEE 3007.2—IEEE Recommended Practice for the Maintenance of Industrial and Commercial Power Systems.


205.3 General Maintenance Requirements: This expanded section includes new language that states, “The equipment owner or the owner’s designated representative shall be responsible for maintenance of the electrical equipment and documentation.”


A new informational note regarding text and calibration labels was added that states, “Common industry practice is to apply test or calibration decals to equipment to indicate the test or calibration date and overall condition of equipment that has been tested and maintained in the field. These decals provide the employee immediate indication of last maintenance date and if the tested device or system was found acceptable on the date of test. This local information can assist the employee in the assessment of overall electrical equipment maintenance status.”


Deja vu?

Been here before? Yes, we have. The 2015 edition will be the tenth time NFPA 70E has been published since it was introduced in 1979. Each new edition continues to improve electrical safety in the workplace.



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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Sep 12, 2014 9:23 am 
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Were there any last minute surprises/changes?


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Sep 12, 2014 10:08 am 
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No major last minute changes that I am aware of like what happened with the 2012 edition.

With the 2012 edition some may recall the last minute change for labeling. It went from "select only one" meaning incident energy or category to "select at least one" That was (and still is) my hot button issue and I would not let up. After posting on the arc flash forum that I was beginning to think the "either/or" language was due to 12 cal/cm^2 PPE not fitting in the normal Category 1, 2, 3, and 4 system, the change was made. I heard from a colleague on the 70E committee that my name was mentioned during the decision to make the change - I wasn't there so I'll take his word for it.

People were using the term "PPE Category" to get around the issue. This time around they changed HRC to "PPE Category" and are doing the same thing, you can't list incident energy and PPE Category. Pretty sure it really is about the 12 cal/cm^2 PPE rating because logically it makes no sense. I have an article coming out in the September issue of Electrical Contractor Magazine about using only the arc rating and keep it simple. However, I also suggest assigning a working distance with the arc rating which at the moment is not required. An arc rating doesn't mean much if you don't know what distance it is based on.

It will be interesting to see how the 2015 Edition is received. There are a few controversial issues and in talking with several friends on the 70E committee, these issues did not receive a clean vote. There were quite a few that objected but there were enough votes to pass.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Tue Sep 16, 2014 8:35 am 
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Jim Phillips (brainfiller) wrote:
The revised language states at least one of the following:


•  Either the available incident energy with the corresponding working distance or the arc flash PPE category in Table 130.7(C)(15)(A)(b) or Table 130.7(C)(15)(B) shall be listed but not both.


•  Minimum arc rating of clothing is required.


•  Site-specific level of PPE is required.



I am a bit confused here. The second and third bullet points above have a notation "is required". Are all the three items above, or at least one only required? Also, could someone clarify how site-specific level of PPE would be determined?


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Tue Sep 16, 2014 2:15 pm 
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It says at least one of the following:

a: incident energy or arc flash PPE category, but not both
b: minimum arc rating of clothing
c: site-specific level of PPE

I'm wondering, if you use a category system for the site-specific level of PPE that is based on incident energy, as long as you don't call it 'Arc Flash PPE Category' there should be nothing preventing you from doing so?

Call it HRC and your existing labels are instantly 2015 proof.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Wed Sep 17, 2014 4:21 am 
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The "Is required" does not belong there and was deleted. I checked my draft that was used and it was not there so not sure how it ended up in the final document. Thanks for the catch!

The HRC comment is amusing. Many recall that the last time around people were saying you can not mix HRC with incident energy. OK, so people began to call 1,2,3 and 4 PPE categories to get away from the term HRC. This time 70E changed the term category that people moved to and say you can't use that term with incident energy. Hummm... so if people move on and call it PPE level (which many do) to describe 1,2,3,4 will level be the next word that can't be used to refer to PPE "groupings" i.e. 1,2,3,4? For now, many people are sticking with Level.

Everyone's thoughts?


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Wed Sep 17, 2014 1:01 pm 
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I like term "Hazard Level" better.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Oct 10, 2014 8:35 am 
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I've just finished reviewing new NFPA 70E year 2015 Tables 130.7(C)(15)(a) and 130.7(C)(15)(b) and I have reservations against using the NFPA 70E table method for arc flash assessment and labeling. In order to use the table method, you must be sure that the parameters of your electrical system are covered by Table 130.7(C)(15)(b), specifically:

1. It applies to equipment listed in Table 130.7(C)(15)(a) only.

2. The method implies you have performed short circuit analysis and calculated available short circuit current.

3. To use the table method, you have to make sure fault clearing times do not exceed the maximum values specified in Table 130.7(C)(15)(b). However, in order to determine clearing time, you need to know predicted arcing current value. The arcing current is a function of system parameters and equipment geometry, can vary greatly and in many cases its value is far less than the available bolted fault current value. The only proven way I am aware of to calculate arcing current in LV power systems is by using the incident energy analysis method. However, NFPA 70E 2015 specifically prohibits mixing both incident energy and table methods rendering the table method quite impractical.

4. Table method is not applicable for tasks with less than 18 inches working distance

Also, the table method seems to be overly conservative and calls for PPE category 4 in 6 out of 10 system types described in Table 130.7(C)(15)(b).

Conclusion: I would not recommend the arc flash PPE category table method for conducting arc flash analysis.

On the other hand, once you've done short circuit analysis, calculated arcing currents and determined fault clearing time, you are only a step away from determining incident energy and arc flash boundary using the IEEE 1584 incident energy method without restrictions presented by bullet points 1 and 4 and the dilemma described in point 3.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Oct 17, 2014 8:38 am 
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arcad wrote:
Also, the table method seems to be overly conservative and calls for PPE category 4 in 6 out of 10 system types described in Table 130.7(C)(15)(b).


Not really. The alternative would be to run the same analysis again but offer a range of short circuit currents. Then there would be more options, except...

Quote:
On the other hand, once you've done short circuit analysis, calculated arcing currents and determined fault clearing time, you are only a step away from determining incident energy and arc flash boundary using the IEEE 1584 incident energy method without restrictions presented by bullet points 1 and 4 and the dilemma described in point 3.


And this is the reason for the problem.. There are two approaches that can alleviate this but nobody is going to be happy with either one:

1. Using measured data from a battery of tests for specific equipment. That's what NESC did for an equipment-specific table.

2. Get rid of the trip time requirement. How to do this? Construct a table as follows. The left hand column would list equipment descriptions. A second column would break down each equipment category into various PPE levels. Subsequent columns would list clearing times for instance 0.1 seconds, 0.5 seconds, 1 second, and 2 seconds. Then all the table entries would list maximum short circuit current. If clearing time is unknown then default to the 2 second column (maximum).

The second table in NESC lists nominal voltages in the first column and maximum short circuit values in the second column. The header lists PPE levels and the table entries are all clearance times. The recommended table substitutes equipment for voltage levels and swaps short circuit values for clearance times.(

This would provide what is desirable....a way to get to an arc flash rating on equipment where little to nothing is known about it, without constructing an entire power system analysis. The results would be conservative, perhaps overly so.

Otherwise the only approach that can be taken, and the one that is commonly used, is to simply IGNORE the parameters in the table and select PPE based on the equipment descriptions alone. Previously data collected by Doan suggested that following the 70E tables (without validating the parameters) provided adequate PPE in 50% of the cases for which he was able to obtain information. As of 70E-2015, the H/RC requirements where PPE was relaxed but not eliminated (such as H/RC 0 or 2 with H/RC 4 equipment) have been removed, and head protection for 1.2-4 calc/cm^2 has increased. So the table entries have become more conservative but not by any great margin.

The upside to a table of this nature is that the one parameter that is difficult to estimate is clearing time. This approach uses the generally accepted principle that 2 seconds is a good upper limit on opening time. It is still something of an assumption but one that has stood the test of time. A CONSERVATIVE estimate of short circuit currents is readily available and is not much more difficult to calculate than an ampacity calculation. The downside of simplified short circuit estimates is that they overestimate the current and thus underestimate the clearing time by a wide margin.

The downside of such a table is that the allowable short circuit current will not be large. This will limit the usefulness of the table. However it will also encourage outright power system analysis whenever the available short circuit current is significant and the risk of injury due to arc flash is highest.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Oct 17, 2014 10:30 am 
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PaulEngr wrote:
Otherwise the only approach that can be taken, and the one that is commonly used, is to simply IGNORE the parameters in the table and select PPE based on the equipment descriptions alone. Previously data collected by Doan suggested that following the 70E tables (without validating the parameters) provided adequate PPE in 50% of the cases for which he was able to obtain information. As of 70E-2015, the H/RC requirements where PPE was relaxed but not eliminated (such as H/RC 0 or 2 with H/RC 4 equipment) have been removed, and head protection for 1.2-4 calc/cm^2 has increased. So the table entries have become more conservative but not by any great margin.

The upside to a table of this nature is that the one parameter that is difficult to estimate is clearing time. This approach uses the generally accepted principle that 2 seconds is a good upper limit on opening time. It is still something of an assumption but one that has stood the test of time. A CONSERVATIVE estimate of short circuit currents is readily available and is not much more difficult to calculate than an ampacity calculation. The downside of simplified short circuit estimates is that they overestimate the current and thus underestimate the clearing time by a wide margin.

The downside of such a table is that the allowable short circuit current will not be large. This will limit the usefulness of the table. However it will also encourage outright power system analysis whenever the available short circuit current is significant and the risk of injury due to arc flash is highest.


My point was that the modified NFPA 70E 2015 table method is outright unusable. Fault clearing time is required in order for the method to be used. The time cannot be determined unless arcing fault current is known. Although, the NFPA 70E incident method provides formula from the IEEE 1584 Guide for calculating arcing current from the IEEE 1584 Guide, the formula is integral part of incident energy method and the new standard now SPECIFICALY prohibits mixing both incident energy and table methods.

One can make assumptions about the amount of short circuit current, arc duration etc., and use values picked from the sky when selecting PPE. However, that wouldn't be engineering but wild guess. According to what you say, this is exactly what many people are doing. It's hard to believe but sounds like truth.

I would just forget about NFPA 70E table method due to the inherent controversy introduced in the NFPA 70E year 2015 edition. I would consider using IEEE 1584 empirical model (c/o NFPA 70E incident energy method) for arc flash analysis. In fact, this is the only other option provided by the NFPA standard.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Fri Oct 17, 2014 10:46 am 
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I view the tables as a stop gap method to get something quickly in place if there is no arc flash program, using estimates and best guesses for the information you don't know. The company needs to then follow up as quickly as possible with an actual arc flash study, from which they then use actual calculated incident energy values.

This has been the case, I believe, for many years. I think 70E might be trying to nudge us further down this path in the latest release.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Wed Nov 05, 2014 2:06 pm 
When does NFPA 70e 2015 take effect? It seems OSHA is slow in adopting new codes, so realistically I probably have years before having to update my existing labels.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Wed Nov 05, 2014 2:14 pm 

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So when does this take effect? Does OSHA or NEC have to adopt it first? My impression is that my existing labels are good until it is time to do an update.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Wed Nov 05, 2014 7:27 pm 
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bikenut01 wrote:
When does NFPA 70e 2015 take effect? It seems OSHA is slow in adopting new codes, so realistically I probably have years before having to update my existing labels.


Per Page 1 of NFPA 70E-2015 it states "It was issued by the Standards Council on July 14, 2014, with an effective date of July 29, 2014, and supercedes all previous editions."

As far as labels, Article 130.5(D) contains an exception that Labels applied prior to September 30, 2011 are acceptable if they contain the available incident energy or required level of PPE.

_________________
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www.workplacesafetysolutions.com


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Thu Nov 06, 2014 7:14 am 

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I don't understand the relevance of the date September 30, 2011. If the new code takes effect in July 2014, why wouldn't all labels installed prior to that date be OK?


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Thu Nov 06, 2014 9:39 am 

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Does OSHA adopt NFPA 70E in general or does it cite specific versions? NEC-2014 cites NFPA 70E-2012 in the informational note. Therefore, I assume it will be 2017 before they update the reference to NFPA 70E-2015. The root of the question is, when do I need to update my labels and provide the additional PPE and training required by the new standard?


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Thu Nov 06, 2014 10:29 am 
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arcad wrote:
I would just forget about NFPA 70E table method due to the inherent controversy introduced in the NFPA 70E year 2015 edition. I would consider using IEEE 1584 empirical model (c/o NFPA 70E incident energy method) for arc flash analysis. In fact, this is the only other option provided by the NFPA standard.


NFPA 70E-2015 suggests using an engineering study but does not specify a specific method. Annex D.8 lists different options including 2 Lee methods, one by Doughty/Neal that were essentially the predecessors to IEEE 1584. The previous edition also listed the table method in NESC but in 2015 they deleted the reference, most likely due to in fighting, so there is no longer any guidance except Lee above 15 kV, and Lee is so bad at that voltage that even OSHA doesn't recommend it in their new 1910.269 Appendix E. Since 70E does not mandate a specific method I can also further throw in the Duke Heat Flux software program as well as ArcPro. And while we are at it, we can argue about the various methods and accuracies of the "piecewise" calculations that SKM, ETAP, etc., do as "IEEE 1584" calculations but include assymetrical fault currents. And finally, we have outright test work as an option and probably the best (though the most expensive) one at that. If anything, OSHA in the 1910.269 Appendix has clearly endorsed ArcPro and although they don't come out and say what a "commercial software" is in IEEE C2 (NESC), it's also ArcPro. So that is the strongest endorsement available for any particular arc flash study method, although that particular model is inappropriate for typical industrial conditions that are modelled by IEEE 1584.

Finally, it's not "pulling numbers out of the air" to use 1584 for every part of it except to insert 2 seconds as the fault clearing time. IEEE 1584 specifically suggests the "2 second rule" although it is indeed more of a suggestion than a "rule". Every software package out there uses some kind of simulation time cutoff for calculating arc flash, although it is commonly adjustable. It has been widely adopted for all manner of uses so it is hardly without merit of any kind, except in a very strict academic sense. Out of the other factors, gap is given in tables or easily measured, as is nomnal voltage. That leaves current as the only "unknown" input. If current is estimated by a conservative method such as the ANSI method, though the result is higher than reality, since we've already assumed maximum arcing time then trip time doesn't really matter and over-estimating fault current is not harmful though under-estimation is. All that remains is to argue about the relative risk in generating an under-estimated result from ANSI. It happens but isn't that common.


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 Post subject: Re: 2015 NFPA 70E Changes
PostPosted: Thu Nov 20, 2014 12:17 pm 
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PaulEngr wrote:
NFPA 70E-2015 suggests using an engineering study but does not specify a specific method. Annex D.8 lists different options including 2 Lee methods, one by Doughty/Neal that were essentially the predecessors to IEEE 1584. The previous edition also listed the table method in NESC but in 2015 they deleted the reference, most likely due to in fighting, so there is no longer any guidance except Lee above 15 kV, and Lee is so bad at that voltage that even OSHA doesn't recommend it in their new 1910.269 Appendix E. Since 70E does not mandate a specific method I can also further throw in the Duke Heat Flux software program as well as ArcPro. And while we are at it, we can argue about the various methods and accuracies of the "piecewise" calculations that SKM, ETAP, etc., do as "IEEE 1584" calculations but include assymetrical fault currents. And finally, we have outright test work as an option and probably the best (though the most expensive) one at that. If anything, OSHA in the 1910.269 Appendix has clearly endorsed ArcPro and although they don't come out and say what a "commercial software" is in IEEE C2 (NESC), it's also ArcPro. So that is the strongest endorsement available for any particular arc flash study method, although that particular model is inappropriate for typical industrial conditions that are modelled by IEEE 1584.

Finally, it's not "pulling numbers out of the air" to use 1584 for every part of it except to insert 2 seconds as the fault clearing time. IEEE 1584 specifically suggests the "2 second rule" although it is indeed more of a suggestion than a "rule". Every software package out there uses some kind of simulation time cutoff for calculating arc flash, although it is commonly adjustable. It has been widely adopted for all manner of uses so it is hardly without merit of any kind, except in a very strict academic sense. Out of the other factors, gap is given in tables or easily measured, as is nomnal voltage. That leaves current as the only "unknown" input. If current is estimated by a conservative method such as the ANSI method, though the result is higher than reality, since we've already assumed maximum arcing time then trip time doesn't really matter and over-estimating fault current is not harmful though under-estimation is. All that remains is to argue about the relative risk in generating an under-estimated result from ANSI. It happens but isn't that common.


In NFPA 70E table method, fault clearing time limits are 0.03 sec, 0.24 sec, 0.33 sec and 0.5 sec. Therefore, the IEEE 1584 two seconds rule could not be applied when determining PPE category and arc flash boundary using the NFPA 70E table method. Once again, fault clearing time is required in order for the NFPA 70E table method to be used. The time cannot be determined unless arcing fault current is known. Although, the NFPA 70E incident method provides formula from the IEEE 1584 Guide for calculating arcing current from the IEEE 1584 Guide, the formula is integral part of incident energy method and the new standard now SPECIFICALLY prohibits mixing both incident energy and table methods.

As far as choosing an engineering study method as suggested by NFPA 70E-2015, I would limit selection to the methods already included in NFPA 70E-2015 Annex D.8. One can argue the methods are not perfect, but Duke Heat Flux and ArcPro have limitations as well. At least, methods listed in NFPA 70E come accompanied with detailed description including calculation procedure and are therefore open to scrutiny. Contrary to them, Duke Heat Flux, ArcPro, ArcFlashTables ( http://arcflashforum.brainfiller.com/viewtopic.php?f=24&t=3482 ) methods are questionable proprietary methods with calculations procedures not made known to public. Anyone using the proprietary methods can only guess how accurate are they, what assumptions they are based on and how reasonable are the assumptions.

Also, applying short circuit current values calculated using ANSI method (mostly conservative, sometime underestimating = highly inaccurate method in first place) and two (2) second arc duration in calculating incident energy and arc flash boundary would result in unrealistically high incident energies and expansive arc flash boundaries in most cases in which case the entire facility would have to be declared an emergency with no one allowed to enter it in unless wearing space suit. Therefore, regardless of what engineering method is chosen, the person applying it for arc flash analysis should do necessary and proper home work conducting comprehensive short circuit study (including upstream, downstream short circuit current contribution, taking into account both equipment resistance and reactance values etc.), determining arc duration as a function of predicted arcing current and upstream protection device time-current characteristics prior to calculating incident energy and arc flash boundary.


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