Since the next edition of IEEE 1584 is nearing completion, has your company/your clients delayed updating or performing any arc flash studies until the next edition is out?

Btw, the next edition is still in the final approval stages.

Here is this week's question:

Have you delayed arc flash studies until the next IEEE 1584 is released?
Yes - Waiting for the next edition
No - Business as usual
It depends
Doesn't apply - no studies

We are in the middle of one study. Our client doesn't know or care about IEEE 1584; they just want the study done on schedule.

Most of our clients do not know that IEEE 1584 is being revised nor do they care. Usually the study is required either by the AHJ, new construction specifications, or corporate directive.

The real question will be, "Will OSHA, NFPA 70E, and AHJ allow and grandfather the older AF studies using IEEE 1584 2002?" If not, there will not be enough Power Engineers in the world to be able to update all of the previously completed studies in a reasonable period of time.

just an opinion, whether the client understands what 1584 is, or not, it is the responsibility of the expert (us) to give them their options. If we do calculation now and the new standard dramatically increases the incident energy, is it fair if we do not let them know there is that possibility.

Hi Bob! I asked a question a year or two ago would people revise studies immediately or phase them in over the 5 year NFPA 70E review cycle. The good news is most will phase in over 5 years. So.... no retirement for you for a while!

Why the 5-year cycle btw? Is that an arbitrary number someone came up with or is there a reason for this?

We made a substantial investment in field verifying and modeling our center about 8 years ago (medium voltage distribution system and building distribution down to panelboards, mcc's and large branch circuits for approximately 200 buildings). We update our center model whenever mods, additions and demolition are completed on an ongoing basis. The 5 year review cycle seems to be not applicable us since we are constantly revising the model. However, there may be facilities in our system that are not changed in 5 years and the old calculations are still applicable.

Am I to infer from this thread that even though no mods have been done for a facility in over 5 years, that the calculations should be redone using the 2018 edition of IEEE 1584? If this is the case, this is not a trivial expense for us and I assume many others out there with large campus type facilities. There are many more variables to consider when using the 2018 IEEE 1584 calculations, which will require a tremendous redo of field verification efforts to collect new data that wasn't required by the previous calculation methods (electrode orientation, size of enclosure, etc.)

For new installations or modifications, I absolutely would collect the required data and use the new calculation methods. But I think it may be unreasonable to think that we would go back and redo calculations on an unchanged facility just because 5 years has elapsed. We don't make existing installations update just because the NEC changed. If nothing has changed, is it being suggested that we need to revise AF calculations just because the IEEE 1584 was updated? Wondering who else has a similar perspective. Will IEEE 1584 address this?

The 5 year cycle is from NFPA 70E and is to direct that studies are reviewed at least once during the 5 year cycle or if there are significant changes. It sounds like your company already has more of a continuous review / revision cycle. I have always take the view that this is more about making sure the PPE recommendations don't change. If a number goes up or down a bit, my view is that isn't significant. But, if an incident energy jumps and higher rated PPE is required, that is significant.

As far as the next edition of IEEE 1584, many that I talk with seem to be leaning towards addressing it (new software updates) during the next review cycle.

I agree but unless you run the new calculations, I'm not sure how you can make the comparison. And to do the new calculations, it seems like a lot of additional work will be required. This is a major source of concern because of additional costs associated with collection of the additional data. I don't think there will be any near term impacts, but time will tell.

It is possible to simply switch models. We did this back when NFPA 70E-2004 model vs. Lee vs. IEEE 1584 was still a "thing". NFPA 70E-2004 model was essentially an early and simplified version of IEEE 1584-2002. Electrode orientation really isn't that bad if you consider that the equipment libraries should be able to capture some of that data as well as enclosure sizes. Already when you select say a switchgear breaker, most software automatically defaults to the large box (switchgear) enclosure. But obviously right out of the starting gate it may be a while before the three major software vendors start incorporating that data into the models. Also because electrical equipment is failure modular, I'm expecting that the data collection will actually go fairly quickly. Might take a couple minutes to mark down the size of a cell/bucket on the first one but then all the others that are the same size just need to be noted, not measured. Plus all the old data can be reused for those who have existing studies. It's just a software calculation change. The big thing is as Jim said about 10-15% might change values a little bit. But in practice every time I've been through a 5 year update, you get that anyway. It's amazing from one survey to the next how many things get missed or assumptions that are made that get caught on the next survey.