There are a lot of things that I am seeking a better understanding on with the new NFPA 70E and 1584. These include
- Generally – trying to render a practical implementation. Take for instance arc flash PPE determination.
The way I read it is there are two methods
The arc flash PPE Category method in accordance with 130.7 ( C ) (15). This method would require determination of the task. If you're in a new plant, you can not judge what the tasks being preformed. This is better suited to be placed on a work order that defines the task with the proper PPE. So what’s left is to go with the 130.5 (G)
The incident energy analysis method in accordance with 130.5 (G) lists the incident energy and two tables by which a qualified person needs to select. The label just gives the incident energy levels.
- What to do if you have old labels in one part of the plant and put in a new building or a similar building that is located at a different site in accordance with 130.5 (G). Now someone who's working on it would see two different labels depending on where they are. Previous version of NFPA 70E resulted in arc flash labels having the incident energy level, category and PPE required.
- The 240/120 Volt exception in 1584 that was used in conjunction with 70E. Now 1584 says - sustainable arcs are possible but less likely at 240 V or less with an available short circuit current less than 2000 amp. “are possible” is a real perplexing comment which neither provides direction or reason, or where to go from here. Rather it leaves a sense of hand ringing. I’ve actually started to get into discussions on whether receptacles or light switches need arc flash labels.