Arc Flash Label on Panels and criteria?

[Prototype1]

I want to get better understanding of Arc flash labels.

I visited five different buildings to inspect electrical panels and determine if they have arc flash labels. Most of the panels lack labels on their doors, though some interior panels bear warnings such as 'Danger: Hazard of electrical shock, explosion, or arc flash.' Among the panels with labels, the attached photo depicts a general warning label indicating 'Danger Arc Flash Hazard.'

However, I am confused as these labels lack additional information, such as 'Arc Flash boundary, Incident energy, Shock hazard, Arc rating, and PPE Category.'

According to the 2023 NEC, the service equipment label now applies to all feeder-supplied equipment rated 1,000A or greater. However, the required information for the label has been removed, with the specification that it should adhere to applicable industry practices and include the date of application.

Referencing NFPA 70e table 130.7(c)15(a), it stipulates specific parameters for panels, such as a maximum of 25KA available fault current, maximum fault clearing time of 0.03 seconds, and a minimum working distance of 455 mm (18 inches), assigning Arc flash PPE category one.

My question pertains to whether the panel must be rated above 240 V or 480 V to necessitate detailed information on 'Arc Flash boundary, Incident energy, Shock hazard, Arc rating, and PPE Category.'

I would appreciate any assistance regarding Arc flash labels.

 

[jim dungar]

There are really two types of Arc Flash labels, however many people try to use a hybrid one.

The first is your general 'warning' label that should meet ANSI Z535 standards. Manufacturers have been including this label for about 20 years. It has a color coded key word, a description of the issue, and what to do to avoid it.

The second label would be an informational label, which likely does not follow any thing more than a company standard format. This is the label with things like Incident Energy and required PPE.

A hybrid lable usually include a keyword, but does not follow ANSI standard for color or information. These labels often have formatting and information per the company/employer's safety plan, although it is not uncommon to see them use color coding and other information chosen by the Arc Flash software companies.

 

[David Castor]

There are two different standards being referenced. NFPA 70 (NEC) is generally mandatory across the US, although different states are on different versions. NFPA 70E is a consensus standard related to electrical safety in the workplace. It is not legally mandatory. Most of the specific requirements for arc-flash hazard analysis and labels are in NFPA 70E. The requirements in NFPA 70E regarding the specifics of labels are minimal. It only tells you the minimum information that must be on the labels.

Also, you will still find many facilities with no arc-flash labels and no arc-flash safety program.

 

[Prototype1]

There are two different standards being referenced. NFPA 70 (NEC) is generally mandatory across the US, although different states are on different versions. NFPA 70E is a consensus standard related to electrical safety in the workplace. It is not legally mandatory. Most of the specific requirements for arc-flash hazard analysis and labels are in NFPA 70E. The requirements in NFPA 70E regarding the specifics of labels are minimal. It only tells you the minimum information that must be on the labels.

Also, you will still find many facilities with no arc-flash labels and no arc-flash safety program.

I was assigned for this project. So, I am confused on what labels should be on each panel. Will the label will be different on 240V/120V panel then 277/480 volt panel label?

 

[David Castor]

Generally, each panelboard gets a single arc-flash hazard label. The label has the same information regardless of the voltage level.

 

[jim dungar]

Generally, each panelboard gets a single arc-flash hazard label. The label has the same information regardless of the voltage level.

Manufacturers usually include a general 'key word' label, like Danger, that conforms to ANSI and UL this warns about and provides information on how to avoid things like electric shock and arc faults.

The second label is often generated by arc flash analysis software in a format per the customer's safety program, the information on this label usually includes voltage, arc flash incident energy, and PPE requirements.

It is common to see these two labels conflict with each other in regards to both key words and colors. I have seen red Danger and green Arc Flash labels on the same equipment.

 

[Jpflex]

I want to get better understanding of Arc flash labels.

I visited five different buildings to inspect electrical panels and determine if they have arc flash labels. Most of the panels lack labels on their doors, though some interior panels bear warnings such as 'Danger: Hazard of electrical shock, explosion, or arc flash.' Among the panels with labels, the attached photo depicts a general warning label indicating 'Danger Arc Flash Hazard.'

However, I am confused as these labels lack additional information, such as 'Arc Flash boundary, Incident energy, Shock hazard, Arc rating, and PPE Category.'

According to the 2023 NEC, the service equipment label now applies to all feeder-supplied equipment rated 1,000A or greater. However, the required information for the label has been removed, with the specification that it should adhere to applicable industry practices and include the date of application.

Referencing NFPA 70e table 130.7(c)15(a), it stipulates specific parameters for panels, such as a maximum of 25KA available fault current, maximum fault clearing time of 0.03 seconds, and a minimum working distance of 455 mm (18 inches), assigning Arc flash PPE category one.

My question pertains to whether the panel must be rated above 240 V or 480 V to necessitate detailed information on 'Arc Flash boundary, Incident energy, Shock hazard, Arc rating, and PPE Category.'

I would appreciate any assistance regarding Arc flash labels.

You mentioned that service equipment 1,000 A or greater will require this arc flash label. Residential services to my understanding have always been exempt from being required to have these labels unless it has something to do with a 2023 update or possibly being such a high ampacity 1,000 amperes not common to residential?

I used to print arc flash labels and labels for available fault current with date for my past industrial job on panel equipment. Doing the math for available fault current was easy to the point of the transformer if you had its information such as impedance and KVA rating. The labels are more specific now and letters have to be a specific size with red and white theme

 

[David Castor]

The labels are more specific now and letters have to be a specific size with red and white theme

Do you have source for this? AFAIK, the 2024 NFPA 70E label requirements haven't changed much.

 

[jim dungar]

Do you have source for this? AFAIK, the 2024 NFPA 70E label requirements haven't changed much.

Probably a customer specifications being mistaken as code.
Trainers are really good at saying stuff like this.

 

[Prototype1]

Generally, each panelboard gets a single arc-flash hazard label. The label has the same information regardless of the voltage level.

So, You can have Danger Arc Flash Hazard, general 'warning' label on the panel boards. and not require to have The second label that includes voltage, arc flash incident energy, and PPE requirements on panelboard door?

 

[David Castor]

Per NFPA 70E, you need a label with voltage, arc-flash incident energy or PPE level, and the arc-flash boundary on any equipment likely to be serviced or examined while energized.

 

[don_resqcapt19]

So, You can have Danger Arc Flash Hazard, general 'warning' label on the panel boards. and not require to have The second label that includes voltage, arc flash incident energy, and PPE requirements on panelboard door?

The danger arc flash hazard label is the one required by 110.16(A). If your installation falls under 110.16(B), then you need more specific information. The words "arc flash label shall be in accordance with applicable industry practice" in 16(B) are intended to require the information that is required by 70E.

 

[Jpflex]

The danger arc flash hazard label is the one required by 110.16(A). If your installation falls under 110.16(B), then you need more specific information. The words "arc flash label shall be in accordance with applicable industry practice" in 16(B) are intended to require the information that is required by 70E.

I’ll have to check if the new company I’m working for is listing the maximum available fault current amperes on the arc flash labels tor their 1500 VDV to 43,500 VAC inverters tied to grid?

 

[Jpflex]

You mentioned that service equipment 1,000 A or greater will require this arc flash label. Residential services to my understanding have always been exempt from being required to have these labels unless it has something to do with a 2023 update or possibly being such a high ampacity 1,000 amperes not common to residential?

I used to print arc flash labels and labels for available fault current with date for my past industrial job on panel equipment. Doing the math for available fault current was easy to the point of the transformer if you had its information such as impedance and KVA rating. The labels are more specific now and letters have to be a specific size with red and white theme

Good points on both post above. Yes such labels have been exempt for most residential services. However, you brought up calculating maximum available fault current up to the service transformer. I agree the calculation is easy at this point if the transformer impedance is known but I have never derated the value based on service or feeder run length and conductor size. How do you make this part of calculation easier? I know the NEC code book calls for these calculations but I’m not sure if they gave examples or math formula to do this?

 

[Jraef]

I think it's also important to understand that NFPA 70E calls for detailed arc flash labeling on equipment "that may need examination, adjustment, service or maintenance while energized."

I find that this is often why people get confused when they see labels that don't offer details as to what the PPE, Incident Energy, Boundaries etc. are. It's usually because those panels do NOT have anything inside that needs examination, adjustment or service while energized. If the required electrical safety program documents a procedure in which live work is not permitted without being pre-authorized by multiple levels of management, and is restricted to only qualified electrical workers who will KNOW the proper procedures, the level of detail on the labels is not as important.