Power Distribution panel issue

We are working on a project that includes the requirement for us to provide a 400A 480vac distribution panel with breakers to supply the 3-phase equipment and a transformer. We had planned to use an off the shelf panelboard with a 3R enclosure, but because the equipment is going in a washdown area all the panels have to be built using the Hoffman stainless steel slope top enclosures. I was wondering if any of you have done this type of thing using a bus and breakers from Square D and then just mounting this inside a Hoffman enclosure? Any suggestions otherwise?

rta53 said:

We are working on a project that includes the requirement for us to provide a 400A 480vac distribution panel with breakers to supply the 3-phase equipment and a transformer. We had planned to use an off the shelf panelboard with a 3R enclosure, but because the equipment is going in a washdown area all the panels have to be built using the Hoffman stainless steel slope top enclosures. I was wondering if any of you have done this type of thing using a bus and breakers from Square D and then just mounting this inside a Hoffman enclosure? Any suggestions otherwise?

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It's going to affect your UL rating (negatively, that is), but you can have a UL inspector come out and bless it (and get a new sticker in the process).

But the NEC is very clear about not allowing you to create your own system from various parts if there is an approved UL alternative.

When I worked for Kasa, we had a UL inspector come in and inspect every panel we built. At Schneider, the prototype was inspected and any subsequent panel built to that design had to follow the approved design exactly (I needed a pull-up resistor installed in the panel and even something as trivial as that was a no-no).

From a practical standpoint, I don't think there would be anything wrong with your approach. I've installed Square D "guts" in a FPE panel before. No problems, but not quite kosher either.

Actually I failed to mention we are a UL508 panel shop so I suppose we could build a panel with din rail mount breakers. However you then run into the issue of accessing the breakers without having to shut down the entire panel. I think this would be ok with our customer since all the equipment has local disconnects also.

...the equipment is going in a washdown area all the panels have to be built using the Hoffman stainless steel slope top enclosures.

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Could you use a NEMA 4X stainless steel watertight panel like this Cutler Hammer EHB unit? It appears to have three 50-Amp breakers, one 15 Amp, and spaces for 4 more.

http://www.ebay.com/itm/ws/eBayISAP...6248&item=370712316248&lgeo=1&vectorid=229466

What kind of wash down environment?
food, drugs, feed?
What wash down chemicals are being used?
it does make a difference as to the type of enclosure you use.

for food, its SS316 in several plants i know of.

regards,
james

If it has to be a Hoffman Watershed NSF-certified sanitary enclosure, then I would ask Hoffman/Pentair to make a custom modification and add a factory-installed UL-certified 400 Amp CB panel to the enclosure. Big $$$ cost, of course!

Lancie1 said:

If it has to be a Hoffman Watershed NSF-certified sanitary enclosure, then I would ask Hoffman/Pentair to make a custom modification and add a factory-installed UL-certified 400 Amp CB panel to the enclosure. Big $$$ cost, of course!

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Yea it is the Watershed. Don't really have time for a factory modification. We will probably build it ourselves. Hoffman actually sells a busbar system that we might consider. Going to see if AB has a similar product.

rta53 said:

Actually I failed to mention we are a UL508 panel shop so...

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Well, in that case, what does the UL guy say? I can't recall a UL listed piece of equipment that was done this way, but that is not to say that it would be illegal.

If you're talking about mounting the panelboard with the deadfront installed as if it were in its own enclosure (the ultimate extension of this thinking would be to mount the entire panel within the panel. Why not?), then where's the beef?

rootboy said:

Well, in that case, what does the UL guy say? I can't recall a UL listed piece of equipment that was done this way, but that is not to say that it would be illegal.

If you're talking about mounting the panelboard with the deadfront installed as if it were in its own enclosure (the ultimate extension of this thinking would be to mount the entire panel within the panel. Why not?), then where's the beef?

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I'm waiting to hear back from my UL rep about this. And your suggestion about mounting the entire I-Line panel inside the Hoffman is another option I have considered.