Five things to consider for your five-year arc flash update
The National Fire Protection Association (NFPA) Standard 70E Article 130.5 states that an arc flash assessment must be updated if a major modification or renovation takes place, and it must be reviewed periodically at intervals not to exceed 5 years. This does not mean that you should wait five years to perform an update. If changes occur on your electrical system that have the potential to impact arc flash energy, the arc flash assessment should be reviewed immediately.
If minimal changes have occurred on your system, you might be inclined to just slap a new date on the arc flash assessment report and labels and call it good. However, doing so could put you and your employees at risk and result in unintentional safety concerns even though nothing has changed electrically. This article presents five important considerations in implementing a five-year arc flash update.
1. Standards Changes
Arc flash research is ongoing and evolving. Arc flash standards are constantly being updated and many of those updates result in new methods of calculations and new variables that can directly impact calculated energies. For example, the IEEE-1584 2018 update included new electrode configurations that almost doubled incident energies on certain equipment.
When updating your study, make sure you abide by the most current standards and that the engineer performing the study is up to date on the latest ongoing research and standards developments.
2. Label Degradation and Compliance
Not all labels have to be replaced if the energies are still valid from the study update, however, all existing labels should be inspected to ensure they are legible, still adhering, and meet the requirements of the latest NFPA 70E standard. To ensure the labels are reflective of the latest standard and study, each label should be dated or indicate which study they correspond to.
It is important to note that the 2015 edition of the NPFA 70E standard eliminated the term “hazard risk category” and replaced it with the term “PPE category.” Thus, any labels still referencing a hazard risk category should be updated. The NFPA 70E requires that labels contain the following information:
- Nominal system voltage
- Arc flash boundary
- At least one of the following:
- Available incident energy and the corresponding working distance, or the arc flash PPE category for the equipment, but not both
- Minimum arc rating of clothing
- Site-specific level of PPE
Source: NFPA 70E 2021
3. Power Source Changes
It is important to always collect updated source information for the electrical system power delivery points during each arc flash update. Changes to the upline distribution or transmission system could impact the arc flash results and require updates to the study. Relevant changes to the upline system include transformer additions or modifications, conductor modifications or reroutes, protective device changes or additions, new inductive loads, or new generators.
4. Renewable Energy
Along the lines of the source changes, renewable generation also has a direct impact on fault current levels and thus alters arc flash energies. With the growing number renewable energy installations, it is important to consider them in an arc flash analysis. Oftentimes these potential fault current sources are overlooked in an arc flash study, but the cumulative effect of numerous small residential photovoltaic (PV) installations could lead to incorrect arc flash energies and put employees at risk. In addition to PV and wind generation, battery energy storage systems (BESS) also provide fault current contribution that should be included in the analysis.
5. Employee Training
Even if the arc flash study does not change significantly, employees should participate in refreshed training on the safety procedures regarding equipment maintenance, PPE, and arc flash labeling. Employees need to understand when live work is performed, when equipment should be de-energized, how to properly de-energize through lock-out tag-out (LOTO) procedures, how to utilize special arc flash protection if present, what PPE is applicable for certain scenarios, and how to read the labels to determine proper PPE.