Arc Flash Labeling – What You Need to Know

There is often a lot of confusion about what is required for arc flash labeling compliance. Are labels even required? Who requires them? What equipment do they pertain to? What information should they contain? The questions can go on and on. My goal today is to clear up the confusion. I believe by the end of this article you will have a clear picture of where your facility stands currently and what it needs to do moving forward.

Note: We are simply talking about labeling compliance not to be confused with overall electrical safety compliance. For more on that click here.

Is Arc Flash Labeling Required?

The answer is yes. Arc Flash labeling requirements can be found in the National Electrical Code, Article 110.16 for new equipment, NFPA 70E-2009 Article 130.3(C) for existing equipment, and OSHA 1910.335(b)(1) for general safety hazards.

In addition ANSI Z535.4 provides standards for the look and type of warning labels in general.

What Equipment Should be Labeled?

According to NFPA 70 (National Electric Code), Electrical equipment that is likely to require examination or maintenance while energized should be marked with a clearly visible sign or label warning qualified persons of a potential arc flash hazard. Switchboards, panel boards, industrial control centers, meter socket enclosures, and motor control centers all present potential hazards and should be marked.

NFPA 70E specifies that equipment over 50 volts should be labeled.

In a nutshell, any electrical device with a nominal voltage > 50 volts that can be worked on in an energized state should contain an arc flash label. This also includes transfer switches, disconnects, enclosed circuit breakers, starters, contactors and transformers.

Is a Generic Warning Label Compliant?

The answer to this is no. A generic warning label is not compliant. Before 2009 a generic warning label would suffice, but NFPA 70E 2009 changed all that. There is now certain information that is required to be on arc flash labels. The 2012 NFPA 70E identifies three pieces of information that are required.

  1. At least one of the following:
    a. Available incident energy in cal/cm2 and the corresponding working distance.
    b. Minimum arc rating of clothing as tested for arc flash exposure.
    c. Required level of personal protective equipment (PPE) to work in an energized state.
  2. Nominal System Voltage
  3. Arc Flash boundaries, including
    a. Limited approach boundary
    b. Prohibited approach boundary (REMOVED from 2015 Standard)
    c. Restricted approach boundary
Label 1

As of 2009 this label is no longer compliant with 70E.

Label 2

NFPA-70E now requires field labels to show incident energy level or PPE.

Bottom Line

Additional information provided by Easy Power about arc flash labels in Arc Flash Hazard Labeling Do’s and Don’ts.

To summarize, arc flash labeling is not as simple as just placing a warning label on a piece of equipment and walking away. There are certain requirements for type of equipment along with detailed information about the severity of the hazard and approach boundaries. To get this type of information, an arc flash engineering study is necessary. Only then are we able to calculate the incident energy that exists at each device.

It also needs to be understood that simply meeting labeling standards does not mean that you are suddenly NFPA 70E compliant. Click here to see what NFPA 70E compliance means.

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