Where, exactly, is Arc Flash Required

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MPdesign

Member
Location
USA
I am doing some personal training and most of what I see "appears" to say that this is required everywhere.
If so, does that mean it has to be done in a brand new building?
If a brand new building does not have a safe electrical system, then what good is the NEC Code?
Does this mean every building in the USA is required to have this done? What about grandma's house?
Is this adopted by any local jurisdictions?

I am obviously missing many very important points, I just do not know what they are. Can some of you please give me some real infprmation on this? I have already wasted a few hours and I have gotten nowhere.
Thank you!
 

mayanees

Senior Member
Location
Westminster, MD
Occupation
Electrical Engineer and Master Electrician
From the NEC:
110.16 Arc-Flash Hazard Warning.
(A) General.
Electrical equipment, such as switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control centers, that is in other than dwelling units, and is likely to require examination, adjustment, servicing, or maintenance while energized, shall be field or factory marked to warn qualified persons of potential electric arc flash hazards.
 

d0nut

Senior Member
Location
Omaha, NE
If a brand new building does not have a safe electrical system, then what good is the NEC Code?
Outside of power limited, intrinsically safe systems, there is no such thing as a safe electrical system. The NEC and other codes exist to try to protect people from the dangers of electricity. Any time you are working on live equipment, there is an arc flash hazard. The codes deal with how to mitigate that hazard, through proper PPE, remote racking of breakers, arc energy reduction, and other such strategies. The appropriate strategy depends on the equipment and level of hazard present.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
From the NEC:
110.16 Arc-Flash Hazard Warning.
(A) General.
Electrical equipment, such as switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control centers, that is in other than dwelling units, and is likely to require examination, adjustment, servicing, or maintenance while energized, shall be field or factory marked to warn qualified persons of potential electric arc flash hazards.
One might think that a so called "qualified" person would know of the arc flash risk, otherwise they could hardly be called "qualified". According to the code we put signs on equipment to warn people who should already know of the danger, while home owners who are by and large not qualified, we are not going to warn them.
 

tom baker

First Chief Moderator
Staff member
The NEC is an installation standard. Required labels as pointed out above, indicates where arc flash labels are required. NGPA 70E gives the how on arc flash.
Also please review the purpose of the NEC, found in 90.1
 

MPdesign

Member
Location
USA
Thank you all for your input.
There are a few questions that I still do not know.
1) Does this mean every building in the USA is required to have this done?
2) What about grandfathered buildings?
3) Is this enforced by any known local jurisdictions? If so, where?
4) Is this enforced by all known local jurisdictions?
5) Is this required in all jurisdictions now in order to get a Certificate of Occupancy?
6) Let's say we are in West Virginia at a strip shopping center where half is empty and the other half have 8 tenants from nail salons to used clothiers. Are you telling me that people expect each of these shops to have a $5k+ study completed?
7) No-one has addressed what I am seeing as key wording in the text, "and is likely to require examination, adjustment, servicing, or maintenance while energized". I would think that if every nonresidential building was meant to be included, then they would have just skipped this part of the sentence.

I am really just trying to fully understand the issue. Thank you for your insight?
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
If a brand new building does not have a safe electrical system, then what good is the NEC Code?...

I am obviously missing many very important points, I just do not know what they are. Can some of you please give me some real infprmation on this? I have already wasted a few hours and I have gotten nowhere.
Thank you!

It is not about a safe electrical installation, NFPA70E is about safe electrical work practices. You need to keep yourself safe around energized electrical items everywhere you work, however the NEC requirements for labeling apply primarily to commercial and industrial locations and not single family residences. For the a large part, this is because arc flash values can only be calculated for 3phase circuits, when using IEEE519 procedures.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Thank you all for your input.
There are a few questions that I still do not know.
1) Does this mean every building in the USA is required to have this done?
2) What about grandfathered buildings?
3) Is this enforced by any known local jurisdictions? If so, where?
4) Is this enforced by all known local jurisdictions?
5) Is this required in all jurisdictions now in order to get a Certificate of Occupancy?
6) Let's say we are in West Virginia at a strip shopping center where half is empty and the other half have 8 tenants from nail salons to used clothiers. Are you telling me that people expect each of these shops to have a $5k+ study completed?
7) No-one has addressed what I am seeing as key wording in the text, "and is likely to require examination, adjustment, servicing, or maintenance while energized". I would think that if every nonresidential building was meant to be included, then they would have just skipped this part of the sentence.

I am really just trying to fully understand the issue. Thank you for your insight?
1. Not required in dwelling units.
2. IMO, equipment installed prior to the sign requirement does not require the sign, at least by NEC.
3. Probably, it is just a sign. They are cheap and many of these pieces of equipment seem to come with a generic sign already.
4. No idea. There are places where there is little enforcement of much of anything.
5. No idea.
6. There is no study required. The NEC only requires a generic sign like this.
1632501394761.png

7. The code describes things that are specifically expected to require such work. At the bare minimum I would think those would require the sign.
 

MPdesign

Member
Location
USA
I am so sorry - I completely miscommunicated because of my own ignorance.
When is an Arc-Flash Study required? I misunderstood and did not realize that you gentlemen were talking just about signage.
I wrote the questions poorly. I am sorry.
When is an Arc-Flash Study required?

Thank you all for your insight.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
I am so sorry - I completely miscommunicated because of my own ignorance.
When is an Arc-Flash Study required? I misunderstood and did not realize that you gentlemen were talking just about signage.
I wrote the questions poorly. I am sorry.
When is an Arc-Flash Study required?

Thank you all for your insight.
Had to chuckle at the title of you OP as the obvious answer is never. Kidding aside, as others noted this is an NFPA 70E issue not an NEC issue.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I am so sorry - I completely miscommunicated because of my own ignorance.
When is an Arc-Flash Study required? I misunderstood and did not realize that you gentlemen were talking just about signage.
I wrote the questions poorly. I am sorry.
When is an Arc-Flash Study required?

Thank you all for your insight.
It is required if you want to comply with an electrical safety program. Given this is pretty much required by OSHA, it is a requirement for just about any commercial or industrial location.

Some kind of electrical study will be needed anyway to determine the short circuit current available and in most cases the software that does these calculations will also do the arc flash calculations. It is not exactly "free" but it is what it is.
 

kwired

Electron manager
Location
NE Nebraska
About only thing that is in NEC is the mentioned warning signs in 110.16.

outside of that basically comes down to is there employees involved, if so OSHA requirements begin to kick in. OSHA doesn't exactly have it's own set of safe electrical working rules, but indirectly ends up being a situation of NFPA70E is generally what will end up being followed.

What ends up happening is you do studies to determine the potential incident energy at a particular location and that is used to determine what PPE is needed if working on that equipment live.

You can maybe have a general policy that you don't do any live work, but that usually is complicated by troubleshooting tasks where you still need to take live measurements to do the troubleshooting. Also to do any other non live work the first part of the process is to confirm it is not live which means wearing appropriate PPE when checking for voltage.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I think a lot of people beleive there is stuff in the NEC that just is not there, including the arc flash requirements for safety. The NEC people should have just stayed out of that altoghether since it really has nothing to do with the installation itself.
 

MPdesign

Member
Location
USA
In essence, you are all saying that the power's that be, have decided that it would be easier to create a new study for each and every one of millions of buildings (25% of which are empty or almost bankrupt) than to have certain standard PPE that was approved for less than say 600A, 277/480V and 22kAIC?
Is that right?

That sounds about right for the way things go today.
Did I forget to ask, what section requires labeling to not eat the breakers?
I suppose it also has to be written in 4 different languages.

Sorry - long week and I digress.
 

kwired

Electron manager
Location
NE Nebraska
I think a lot of people beleive there is stuff in the NEC that just is not there, including the arc flash requirements for safety. The NEC people should have just stayed out of that altoghether since it really has nothing to do with the installation itself.
All they put in NEC is the 110.16 requirement to warn people that arc flash potential exists, no other associated details are covered by NEC.
Lot of gear already has a warning label of some sort on them from the factory and there is nothing else for installers to do to comply with 110.16, unless you maybe have an inspector that wants a specific size/type of label to be applied.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
In large part much of the electrical safety problem comes from the bizarre idea that every electrician is an expert in everything electrical. That is just nonsense. It would be like saying every chiropractor is also a brain surgeon.

There should be different categories of electricians. Some to run wire and pipe, others for MV, some for single and two family residential, etc.And tailor the requirements to the actual tasks.
 

kwired

Electron manager
Location
NE Nebraska
In large part much of the electrical safety problem comes from the bizarre idea that every electrician is an expert in everything electrical. That is just nonsense. It would be like saying every chiropractor is also a brain surgeon.

There should be different categories of electricians. Some to run wire and pipe, others for MV, some for single and two family residential, etc.And tailor the requirements to the actual tasks.
and there are many that are qualified in multiple number of those categories.
 
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