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 Post subject: who does the study?
PostPosted: Wed Mar 31, 2010 7:28 am 
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I was in NFPA70e training last week and the trainer said that the arc flash study needs to be done by an engineer - according to the standard. Is this true? I have not been able to find it in the NFPA70E standard. I know electrical contracting companies are bidding this kind of work.


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PostPosted: Wed Mar 31, 2010 7:39 am 
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uriah1 wrote:
I was in NFPA70e training last week and the trainer said that the arc flash study needs to be done by an engineer - according to the standard. Is this true? I have not been able to find it in the NFPA70E standard. I know electrical contracting companies are bidding this kind of work.


NFPA70E does not address this issue.


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PostPosted: Wed Mar 31, 2010 7:47 am 
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JBD wrote:
NFPA70E does not address this issue.


They do call out in Annex D under D.5 "The equations must be used only under qualified engineering supervision". I am not saying this means only engineers can perform studies, but am merely stating a fact that might reveal where the trainier is getting his or her information.


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PostPosted: Wed Mar 31, 2010 8:27 am 
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uriah1 wrote:
I was in NFPA70e training last week and the trainer said that the arc flash study needs to be done by an engineer - according to the standard. Is this true? I have not been able to find it in the NFPA70E standard. I know electrical contracting companies are bidding this kind of work.


Nothing says the arc flash analysis needs to be done by an engineer, but the SC study that preceeds it may be required to be done by an engineer in some states.

That being said, having the study not done by an engineer is a bad idea and will likely involve some wrong assumptions. I have seen many EC's selling this seervice using free calculators with horrific results.


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PostPosted: Wed Mar 31, 2010 11:13 am 
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McFlash wrote:
They do call out in Annex D under D.5

Technically the Annex is not part of the standard, it is only a suggestion.


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PostPosted: Wed Mar 31, 2010 1:13 pm 
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State professional engineering registration law may require that the study be done by a professional engineer. Generally, you must be a registered professional engineer in most states to practice engineering. There are exceptions for contractors, manufacturers, state employees, utility employees, etc. Engineering practice is defined in South Carolina as:
Quote:
Practice of engineering' means any service or creative work, the adequate performance of which requires engineering education, training, and experience in the application of special knowledge of the mathematical, physical, and engineering sciences to such services or creative work as consultation, investigation, expert technical testimony, evaluation, design and design coordination of engineering works and systems, design for development and use of land and water, performing engineering surveys and studies, and the review of construction for the purpose of monitoring compliance with drawings and specifications, any of which embraces such services or work, either public or private, in connection with any utilities, structures, buildings, machines, equipment, processes, work systems projects, and industrial or consumer products or equipment of control systems, communications, mechanical, electrical, hydraulic, pneumatic, or thermal nature, insofar as they involve safeguarding life, health, or property, and including such other professional services as may be necessary to the planning, progress, and completion of any engineering services.

This is broad enough to include arc hazard studies, particularly considering the clause about safeguarding life.


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PostPosted: Wed Mar 31, 2010 1:20 pm 
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The Arc Flash analysis and Incident Energy Studies do not have to be completed by an Engineer. Or a better way to say that is that NFPA70E does not require that an engineer complete the study, rather that a study must be documented.

If you are not able to use the tables within NFPA 70E, or if the jurisdiction that you are located includes this type of work as "practicing engineering" as jghrist has stated, then you may require an engineer to do some, or all of the study.

It is best to have a qualified and experienced person complete the information required to complete the arc flash analysis including the Short Circuit, and protection coordination as a worse case situation has to be developed under normal working conditions. This may require educated assumptions to ensure that the information is usable.


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PostPosted: Wed Mar 31, 2010 2:59 pm 
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bluenoser wrote:
If you are not able to use the tables within NFPA 70E, or if the jurisdiction that you are located includes this type of work as "practicing engineering" as jghrist has stated, then you may require an engineer to do some, or all of the study.


Using the tables requires being able to calculate available fault currents at different points and determine the clearing times of the protective devices. Not much less engineering skills required there than doing an actual analysis.

It all depends on local state requirements.


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PostPosted: Wed Mar 31, 2010 7:18 pm 
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You do not have to be a Registered Engineer to perform fault current calculations. Anyone can do it. You only have to be a Registered PE if you plan to charge for your work, or to stamp a drawing. That said, if you are an EE with fault current capability, you could do the work for your own site. If you are not an EE, then doing fault current work should probably be contracted to an outside PE.


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PostPosted: Thu Apr 01, 2010 5:39 am 
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JBD wrote:
Technically the Annex is not part of the standard, it is only a suggestion.


I know that the annexes are not part of the standard but are there as supporting documents. I was merely stating that the traininer that this post was started about might be pulling their information from that line.

Here is what Ohio has to say. "The practice of engineering" includes any professional service, such as consultation, investigation, evaluation, planning, design, or inspection of construction or operation for the purpose of assuring compliance with drawings or specifications in connection with any public or privately owned public utilities, structures, buildings, machines, equipment, processes, works, or projects in the proper rendering of which the qualifications of section 4733.11 of the Revised Code are required to protect the public welfare or to safeguard life, health, or property.

I would think that Arc Flash and SC analysis fall under the category of Practice of Engineering. Other locations in the code lead to the fact that the Practice of engineering should only be conducted under the guidance of a PE.


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PostPosted: Thu Apr 01, 2010 6:40 am 
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McFlash wrote:
I would think that Arc Flash and SC analysis fall under the category of Practice of Engineering. Other locations in the code lead to the fact that the Practice of engineering should only be conducted under the guidance of a PE.


The OP was if there was an OSHA or NFPA (i.e. a national code) requirement for a PE to perform the study. As you and others have pointed out many state and local codes probably already address these studies.

In my opinion a power system study is not a DIY activity and should be left to firms and individuals operating under the applicable licensing and registrations laws of their state.


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PostPosted: Thu Apr 01, 2010 7:12 am 
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Guide for Properly Specifying Studies
I agree with the comments that it is a state by state issue. Many states would consider this an engineering service which falls under state licensing rules.

I am co-chair of a group called IEEE 1584.1 where we have been working (very slowly) on a specification guide for studies. We had to deal with this specific issue. This guide is to create a more level playing field so the "get rich quick" artists that take advantage of owneres that don't understand arc flash get run out of town.

It is Left Up to The Individual State Boards
In this guide, we originally had language that required studies be performed by a registered P.E. We were told to delete the language because it is left up to the individual state licensing boards.

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Jim Phillips, P.E.
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