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Determining AIC for "dead front switch" switch/fuse combo
https://brainfiller.com/arcflashforum/viewtopic.php?f=23&t=6131
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Author:  NeDCE [ Mon Jun 16, 2025 9:56 am ]
Post subject:  Determining AIC for "dead front switch" switch/fuse combo

This question might also be suitable for the software thread, but I'll start here. What's the best way to model a "dead front switch" that contains both fusing and a molded case switch, but is categorized as one unit?

I see this periodically, but my present example is an Eaton FDPBS 364R. It's installed in a distribution switchboard and as a unit, is rated at 200kaic. However, unlike most fused switches, also contains a "molded case switch". None of this gear shows up with any detail on Eaton's website, but the closest I could find from Eaton shows up as rated at 14kaic.

So what would you folks do with this info? Consider it as a 200kaic unit, consider it a fused disconnect and a switch rated at 200kaic and 14kaic respectively, or contact Eaton for clarification?

The second part to this is how to model it in software (EasyPower)? The switch doesn't show up in EasyPower's database.

Author:  mpparent [ Mon Jun 16, 2025 1:10 pm ]
Post subject:  Re: Determining AIC for "dead front switch" switch/fuse comb

I can't put eyes on it, but I'm assuming you have a UL listed assembly. So in that vain, I would categorize it as one unit. I don't use EasyPower, but in SKM, you could just model a switch/fuse. You could then assign the switch w/ a 200kA rating.

Mike

Author:  bbaumer [ Tue Jun 17, 2025 1:50 am ]
Post subject:  Re: Determining AIC for "dead front switch" switch/fuse comb

Probably a 200k rating because of the fuses in series with the MCS. I found a Cutler Hammer labeled version of this switch and it also says 200k. I'd model it as a fuse or fused switch and 200kaic.

I made a video once upon a time about NFDS being 10k and fusible being 100 to 300 k because of the current limiting fuses

There is a pic of a similar one here. Gives an idea of what it looks like:
https://www.electrical.com/Products/Swi ... doQAvD_BwE

Author:  NeDCE [ Tue Jun 17, 2025 9:16 am ]
Post subject:  Re: Determining AIC for "dead front switch" switch/fuse comb

bbaumer wrote:
Probably a 200k rating because of the fuses in series with the MCS. I found a Cutler Hammer labeled version of this switch and it also says 200k. I'd model it as a fuse or fused switch and 200kaic.

I made a video once upon a time about NFDS being 10k and fusible being 100 to 300 k because of the current limiting fuses

There is a pic of a similar one here. Gives an idea of what it looks like:
https://www.electrical.com/Products/Swi ... doQAvD_BwE

That's exactly the one. Just like the one in your link, the sticker on the switch conspicuously has no AIC info on it. I can only believe that it's because the AIC on the inside of the larger switch/fuse assembly door covers the whole assembly.

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