Arc Flash Warning Labels
NEC (National Electrical Code) mandates that hazardous equipment installed or modified after 2002 be required to carry an arc flash warning label. NEC 110.16 specifically mentions “switchboards, panel boards, industrial control panels, and motor control centers that … are likely to require examination, adjustment, servicing, or maintenance while energized.”
NFPA 70E 2015 (National Fire Protection Agency) requires labels to contain the following information:
Nominal System Voltage, Arc Flash Boundary, and at least one of the following:
- Available incident energy and the corresponding working distance, or the arc flash ppe in Table 130.7(C)(15)(A)(b) or Table 130.7(C)(15)(B) for the equipment, but not both
- Minimum arc rating clothing
- Site-specific level of PPE
These values are determined by an arc flash risk assessment (available through ITU), and need to be calculated separately for each piece of equipment labeled.
NFPA 70E also states that arc flash warning labels must be the proper size (at least 4”x 6” recommended to meet required font sizes), ANSI Z535 approved, and be placed so as to be visible to personnel before beginning maintenance or inspection.
A. These durable UV and chemical resistant 3.2 mil laminated vinyl labels include a High-Tack adhesive and rounded corners to prevent peeling. The life span of these labels is 5 years in normal conditions and are capable of withstanding temperatures beyond 165 °F and -50 °F. Sufficient label durability is now a requirement as of the November 2011 NEC (National Electrical Code) update and ITU’s arc flash warning labels more than exceed this requirement.
B. Flash Hazard Category: Represents the level of danger depending on the incident energy. Ratings range in number from 0-4. 0 represents little or no risk while 4 signifies greatest risk. For more information about the different arc flash hazard risk categories click here.
C. Minimum Arc Rating Clothing: Identifies the arc performance of a material or system of materials (PPE) and are expressed in calories per centimeter squared.
D. PPE: Identifies the Personal Protective Equipment that MUST be used according to the hazard category rating.
E. Equipment ID: Identifies panel location within facility.
F. Arc flash warning labels must have the word “WARNING” in black with an orange background and include the standard warning symbol (orange exclamation point with solid black triangle background).
G. Flash Protection Boundary: This is the closest anyone can approach the equipment that has the potential for arc flash, without the use of PPE (Personal Protective Equipment).
H. Limited Approach Boundary: This boundary may only be crossed by a “qualified” person who has been trained in the hazards of the component or equipment being serviced.
I. Restricted Approach Boundary and Prohibited Approach Boundary: Only a qualified person using adequate shock prevention equip¬ment and techniques may cross these boundaries.
J. Maximum Available Fault Current: This is one of the new NEC required features as of November 2011. All the required safety information provided on the label is based on the max. available fault current. If the system is altered in any way resulting in this value to change than the data must be re-evaluated. Companies or utilities will often make changes in the electrical system to be more efficient or to increase capacity. When this is done the max. available fault current changes. As a result the PPE (Personal Protection Equipment) category and the approach boundary information becomes inaccurate and is no longer compliant. Inaccurate information could easily result in serious injury or even death in which the company would be held liable for.
K. The date that the fault current calculation was performed must now be on the label. This is another new feature required by NEC as of November 2011. Arc flash warning labels expire after 5 years. Before labels are replaced an arc fault calculation should be performed to insure that the data on the labels is still accurate. The electrical systems one line diagrams must be updated when any changes are made.