This audio was created using Microsoft Azure Speech Services
Keeping up with safety compliance regulations isn’t always easy, but it is crucial. Arc flash labeling can be particularly confusing as safety guidelines are frequently updated. This blog breaks down the latest 2023 National Electric Code (NEC) and 2024 NFPA 70E requirements specifically related to arc flash labeling.
General requirements for arc flash labeling
Arc flash general hazard labels are warning labels that indicate the risk of an arc flash or serious shock from some type of electrical system. NEC Article 110.16(A) requires these for equipment likely to require examination, adjustment, servicing, or maintenance while energized, such as the following:
- Switchboards
- Switchgear
- Enclosed panelboards
- Industrial control panels
- Meter socket enclosures
- Motor control centers
In many cases, arc flash general hazard labels will be provided by the manufacturer for new electrical equipment. However, existing equipment may need to be updated. Here’s an example of what an arc flash general hazard label might look like:
NEC Article 110.16(B) requires an arc flash label to be field or factory-applied to Service and Feeder equipment rated 1000A or more. Here’s an example of such a label:
What should go on the label?
According to NFPA 70E 130.5(H), the minimum information required for arc-flash labels includes the nominal system voltage, the arc-flash boundary, and at least one of the following: 1) available incident energy and corresponding working distance, 2) minimum arc rating of clothing, or 3) site-specific level of PPE. It’s also common to include shock hazard information.
NEC 110.21(B) requires that all field-applied hazard markings must be durable for their given environment. This means that the words, colors, and symbols on these labels must always be visible, regardless of wear and tear. Handwritten markings are not allowed unless the information on the label is subject to change. See ANSI Z535.2 and ANSI Z535.4 for more information.
Things to consider
NFPA 70E 130.5(H) has an exception for supervised industrial installations; in conditions that ensure that only qualified persons monitor and service the system, arc-flash hazards may be documented by other means, as long as the necessary information is readily available to those likely to perform examination, adjustment, servicing, or maintenance of the equipment while energized.
This exception has led to alternatives such as color-coded tape or painted markings on the floor to denote the arc-flash boundaries for equipment. It’s important to proceed with caution when deploying such alternatives, as they may lead to unexpected results. For example, consider the following scenarios:
- Scenario 1: The equipment covered in NEC 110.16(A) requires general arc flash hazard labels. Service Equipment and Feeder Supplied Equipment require arc flash labels per NEC 110.16 (B). If these labels are not present on other equipment and are substituted by floor markings or other means, the inconsistency could create confusion and threaten the safety of the working environment.
- Scenario 2: Marking the arc flash boundary on the floor in front of the equipment may lead to the assumption that an arc flash hazard is always present. However, evaluating arc-flash hazards involves considering both the likelihood and severity of the flash hazard, which may not always align with such a marked boundary. This is especially true for enclosed equipment under normal conditions of operation and maintenance. This can lead to restrictions that were not intended in the NEC or NFPA 70E.
Arc flash studies can determine the information required for each label. These studies can also help you meet the requirements of NEC 240.67/240.87 for arc energy reduction. NFPA 70B-2023 Standard for Electrical Equipment Maintenance now includes a requirement for arc-flash studies.
The NEC and NFPA 70E describe the minimum requirements for arc flash labeling and many facilities choose to go beyond this in the interest of worker safety. These types of workplace decisions go hand-in-hand with the development of a facility’s Electrical Safe Work Policy.
Keeping up with the latest arc flash safety procedures can help keep people safer by reducing the risk of electrical accidents. For more information, check out the National Electric Code (NEC) updates for 2023.
Add a comment