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Incident Energy Calculations for Industrial Control Panels
https://brainfiller.com/arcflashforum/viewtopic.php?f=23&t=6024		 Page 1 of 1
Author:  bbaumer [ Tue Mar 18, 2025 1:46 pm ]
Post subject:  Incident Energy Calculations for Industrial Control Panels
I've mentioned this particular case on here a few times. I finally got permission to obtain and share photos and videos so I made a video about it on my YouTube channel. I hope it inspires some discussion. Here is the link:

https://youtu.be/D2TL5SpUzXI?feature=shared
Author:  mpparent [ Wed Mar 19, 2025 7:54 am ]
Post subject:  Re: Incident Energy Calculations for Industrial Control Pane
Good video Brent...

I don't know if there is a good answer. When I've modeled these in the past, I have used the default box dim's and used the AFIE calculated by SKM.
Author:  bbaumer [ Wed Mar 19, 2025 8:44 am ]
Post subject:  Re: Incident Energy Calculations for Industrial Control Pane
Thanks Mike.

I'm glad I was able to share the experience. I think there needs to be a different approach to control panels but I'm not sure what it would be. It could be too that this particular case is me just cherry picking something that would likely never happen again and the formulas are just fine. I don't think so however. As I mentioned in the video, there are just too many variables inside a control panel to account for.

A side note, I have noticed that oftentimes control panels will have Class J fuses at their input terminals. I don't know if that is mostly to get a higher withstand rating for the panel or to reduce incident energy or both. For example:

Attachment:
j fuses.jpg
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Author:  bbaumer [ Wed Mar 26, 2025 11:21 am ]
Post subject:  Re: Incident Energy Calculations for Industrial Control Pane
This is interesting.

900+ views of the control panel picture.

Only 60 views of the video so far.

Only one comment on this thread. I was hoping for some discussion on this one, especially was hoping Jim would chime in. Must not be as much of an issue I thought it was.
Author:  JBD [ Tue Apr 01, 2025 12:00 pm ]
Post subject:  Re: Incident Energy Calculations for Industrial Control Pane
I have never cared for calculating AFIE at different points within a control cabinet, unless it is very large with multiple doors. In my opinion this is similar to not calculating AFIE at multiple points within a circuit breaker panel or switchboard. There are too many variables to consider as far as the arc propagation.

My experience has been, current limiting fuses are used in control panels to comply with the SCCR procedures in UL 508A.The fact these fuses could have a possible benefit for AFIE is purely coincidental. The majority of customers have wanted the panels labeled with the arc values at the incoming lugs.
There have been a few times, like multi-section drive cabinets where we did calculate AFIE on the line and load sides of the main switch.
Author:  bbaumer [ Wed Apr 02, 2025 5:21 am ]
Post subject:  Re: Incident Energy Calculations for Industrial Control Pane
JBD wrote:
I have never cared for calculating AFIE at different points within a control cabinet, unless it is very large with multiple doors. In my opinion this is similar to not calculating AFIE at multiple points within a circuit breaker panel or switchboard. There are too many variables to consider as far as the arc propagation...


I agree. Not only that, I don't think you can. At least not accurately. I don't know that IEEE did any of that type of testing and developed the formulas based on that. Most the videos I've seen of their tests basically involved installing a small gauge jumper wire or in a few instances a common tool across phases at the line side and turned it on.

I mentioned in the video that I had asked SKM about using PTW to model the "guts" of a piece of equipment. It was basically power electronics but had terminal blocks, fuse blocks, tap conductors of different gauges, relays etc. similar to a industrial control panel but not exactly. I suspect the answer would be similar if I asked them about modeling the "guts" of a control panel but admittedly I have not tried. Here is the response I got back:

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skm response.jpg
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