NFPA-70E WHICH VERSION ARE WE REQUIRED TO ABIDE BY?

[PE (always learning)]

Hey everyone,

So this is a question relating to Short Circuit, Coordination, and Arc Flash studies. I know that the latest version of the NFPA-70E is 2018, but I was curious if there is anything enforcing what version we use for studies. For example, in different States you might be required to use an earlier version of the NFPA-70 even though the latest version is 2017. I know that obviously it is preferred to use the latest version due to using the most up to date material, but I'm curious if anything is actually requiring what version you use because the NFPA-70E is a standard. Also, I'm curious if this also applies for the IEEE-1584. Please let me know your thoughts.

Best Regards,
Engineer in Training

 

[infinity]

I believe that you need to follow whatever version (if any) that is adopted in your area. Some places don't recognize NFPA-70E at all.

 

[paulengr]

Arc flash falls under the general duty clause under OSHA. You can use any standard for arc flash with no restrictions at all. In fact OSHA 30 CFR 1910.300-399 is based on a 1980s edition of 70E. Due to costs and time involved in chasing versions of standards OSHA has more or less stopped doing this. MSHA only officially recognizes part of the 1976 edition of NEC! So using a 1980s edition might run into issues. The 2000 and 2004 versions were terrible so I would suggest avoiding those. So anything after that should be
OK. Since OSHA doesn’t officially recognize 70E any version is acceptable.

Using an industry consensus safety standard is an affirmative defense legally. Instead of having to justify how you arrive at your conclusions you just have to prove you were following a Code. It is prohibitively difficult from a legal point of view to prove that for instance 70E is superior to say CSA Z462 or IEEE C2 (NESC) never mind a particular year of 70E. So in answer to your direct question no version does not matter. In fact as long as it’s a Code, the particular one does not matter.

But more to your point 70E itself provides only a table based arc flash method. It accepts but does not specifically mandate any particular alternative calculation method. So you can “plug in” the tables in NESC (or OSHA), Lee, IEEE 1584-2002 or 2018, the Wilkins simplified or the very complicated time domain version, the Ammerman or Neal DC methods, the Cooper-Bussmann method, one of several EPRI calculations, Arcpro, or pretty much anything else.

It is up to you as an engineer to exercise judgement in choosing the best method. In fact in some cases such as under 250 VAC and above 15 kV IEEE 1584 and NFPA 70E are definitely not the best because the results are unrealistically high.



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[steve66]

As far as the IEEE 1584 goes, now that the new standard is out, I don't know why anyone would be following the older standard. Especially since its been so long since the last update, and the new standard is based for a much larger set of tests, and should give more accurate results.

Even if you don't have EasyPower software, their website had lots of videos on arc flash studies, including a few that explain the new IEEE 1584. Well worth watching.

 

[PE (always learning)]

Thanks everyone for your comments, very informative. I agree that normally the latest versions of standards and codes should be chosen. I am in the process of revamping my studies and I have to go through and update where the latest references are coming from. Thanks again for the help.

 

[Jraef]

I don't know of ANY jurisdiction that is enforcing any version of NFPA 70E, it's not that kind of standard. There are no "NFPA 70E police".

But how it works is like this:
What OSHA requires is that EVERY employer must have a program for providing a safe workplace with regard to the use of electricity, that the program is periodically reviewed and that all employees are trained on that program annually as it applies to their job tasks. If there is an accident involving electricity and it catches the attention of OSHA investigators, the FIRST THING they will ask the owners/managers/supervisors of the facility is "What is your program for providing a safe workplace with regard to the use of electricity?" OSHA does NOT require that you use NFPA 70E as that program, but they SUGGEST it as an example of what they are going to be looking for. So if the answer is '"Program? What program?", they (all) can be hauled off to jail (as an extreme), fined and/or immediately shut down. Ignorance of the law is no excuse. If they HAVE a program and it is based on NFPA 70E, then what follows are the details of how the accident could have happened if that was followed. If it turns out that the accident could have been avoided had they followed the LATEST ADDITION of the standard, but the employer was following an OLDER version, OSHA may actually accept that, because from their standpoint, they HAVE a program.

The potentially bigger problem however will be that if anyone was HURT and they get a good lawyer, that lawyer will drive a truck through that loophole and the net result may be VERY expensive, regardless of the OSHA determination. So for that reason, insurance companies may have their own requirements for "meeting the latest safety standards".