So, in layman's terms, could one of you guys explain to me why those 1-pole 16A breakers are an issue, versus me having two 2-pole 20A breakers?
Because the PDU is designed to have only the "L" at an elevated voltage. The "N" is assumed to be essentially zero-potential (relative to ground).
If you wire that to a "split phase" where "L" is at 120V, AND "N" is at 120V (both relative to ground) then you are putting everything plugged into it at risk because turning off a single-phase breaker leaves the "N" side at 120V and that is VERY unsafe.
So when HP speaks of 1-phase and lists NA/JP for the models, they're really meaning split-phase, for the higher than 120VAC PDUs, correct? And split-phase is what we have coming into our house, not 1-phase, right? 120VAC - 0 - 120VAC. That clears a lot of stuff up for me.
That device Richard Crowley linked too, I call that a step-up transformer, I'm not sure what they call it,
No. You can wire it "straight-across" (240V in and 240V out) in which case you could call it an "isolation transformer".
But it has many more taps on the primary (input) side, up to 400-500V so that you can tap into higher voltage sources (as in a large industrial situation). In that case you could call it a "step-DOWN" transformer.
Thank you for the clarification there! I didn't thoroughly enough. I understand.
but that would safely complete the requirements to provide the necessary 240VAC single-phase that I need, correct?
Yes. Because you can have the electrician wire the secondary (output) of the transformer for 240V, and connect one side to ground. That makes it a single-phase, ground-referenced source which is exactly what the PDU wants.
I would rather try wiring it up myself, properly. Are you familiar with the brand name at all? Are they any good?
Where I wouldn't be violating any codes, etc?
That is ultimately up to your electrical inspector (from the local governmental jurisdiction.)
In a public/industrial/commercial setting you may need to have a licensed professional engineer "design" the circuit and approve it to satisfy the inspector.
When I said Where I wouldn't be violating any codes, I was speaking strictly about the NEC, not the modifications (more like additions, from how I read the rules) that my local jurisdiction (Steuben County) can make to the NEC. Would this violate any of the NEC that all states must follow? If I cannot get passed that, there's no point going to my local governmental jurisdiction. As I understand it, they can add to the NEC, but they cannot remove stuff from the NEC. So if it fails the NEC right now, no matter where I live in the USA, no local governmental jurisdiction can modify the NEC in such a way where it'd pass.
I want to find something with at least IP44 rating, but maybe IP67. I dunno yet.
Many/most large transformers like that come in a version designed for outdoor installation. Designed for operation in the rain, etc. Is that what you mean? The example I cited claims: "Enclosure Type Indoor/Outdoor", so designed to operate out in the weather. Unless you seek something that will operate immersed? Planning on operating during a flood?
We do not plan on operating it immersed! If it's ever immersed, we have bigger issues to deal with!
I read IP14 as:
1: Any large surface of the body, such as the back of the hand, but no protection against deliberate contact with a body part.
4: Water splashing against the enclosure from any direction shall have no harmful effect.
I read IP6<whatever> as: No ingress of dust; complete protection against contact.
In the basement, there is dust, that's for sure. We have a dehumidifier running 24/7 that has actually helped filter a lot of it (although, that was not the intention for which we installed it). With a little one in the house, we keep a tight eye on her, but she is growing fast, and eventually, she'll be at that age where she'll go down into the basement. And when I was a child, at that age (going down into the basement age, not her age), I found a green fuse and put it in a light socket, thinking it'd glow green when I pulled the string to turn on the light. I also took a screwdriver and put it in an electrical outlet, thinking the end would light up like a lightbulb. Neither experience was very memorable.
Here, we're dealing with a lot more current than what the light socket or receptacle could provide. I would love to say no matter what, she'd never be in the basement unsupervised, but sooner or later, she'll have her own room. We'll do our best to raise her, but she might sneak out at night, or go down into the basement to play, I dunno. If you feel that IP14 rating is good enough for the basement, and she'd have to do some work to get hurt on that, then I'll go for that one.
Finally, is 7.5KVA the correct rating for this unit? Assuming that I'm drawing the entire 7.3KVA from my PDU, and I was drawing that constantly, would that 7.5KVA transformer hold up, or should I maybe consider purchasing a larger one? Right now, we went for 7.3KVA, but made sure we could daisy chain another PDU, if needed. We're a start-up company, just my wife and me. We're going to be close to the 7.3KVA already. It gives us a little wiggle room for a few upgrades / extra equipment, but eventually, we'll need to purchase another PDU, if I've done my math correctly. We're still a ways away from that. The idea now is to try and make some revenue and stop spending cash in the near future. I think we have just about everything we need, minus a few little extras (the transformer, a proper gateway, some shielded ethernet ends, etc).
Your post makes a lot more sense to me now.