Approach I'd Take
I know you are discussing Tesla EVs and their supercharger systems. But I'm going to start out generally and then work towards your specific situation nearer the end, below.
If I were looking to get 3-phase 480 (and I wouldn't mind it, but I don't exactly need it either), I'd just call up the power company and ask them what's involved on their end in providing it to my home.
You can coordinate this with both the power company and a certified electrician to get your entrance panel changed out and appropriate breakers and sub panels arranged for you.
It's not cheap. But it's not a fortune, either.
The Process as I Understand It
You can usually work through the electrician, who will take care of the necessary notifications to the local county office with respect to any needed inspections they may require and also with the power company, as well. So you don't usually need to worry about those details.
The electrician will be responsible for getting all this done in such a way that you are without power for the shortest possible time. This means they need to coordinate their own time along with the inspectors' time so that the power company can re-connect sooner than later.
Disconnecting your power is relatively easy to do. You can just call the power company and ask them to disconnect you. At least in my area, that is really easy and I don't think it costs any money, either. They just pull the plug and go away.
It's the re-connection part where everyone in the world wants a piece of you. The electrician will work quickly to get your entrance panel arranged the way it needs to be, prior to re-connection. There will probably need to be a county inspector who runs out and verifies that everything looks correct. They will certify the work and leave a "sticker" of some kind, signed by the inspector. The power company sends someone out to reconnect you and checks the inspection papers to make sure that part was done. They will also inspect what was done, too. (They aren't going to just trust a piece of paper from the county.) If they see that an inspection was done and that what they also see there looks sensible to them, then they will re-connect your power and then it is up to you and your electrician to work on the inside and re-engage the main breakers and hope nothing goes "bang."
You will pay for the county inspection. But it's usually not a large number. In fact, you usually won't notice the price when compared to the rest. The new panel, breakers, and electrician work will set you back several thousand US dollars. This depends on a lot of factors, but I would not expect it to be any cheaper than $2k (and that would be a bargain) and likely a fair bit more than that. And the power company will want something. Some power companies are really nice about it (mine is) and they charge you less than their own costs. Other power companies may literally rip you off for it. You'll have to call them and ask.
For this, you really will need to call the power company, directly. They usually offer different options depending upon whether or not the service will be above ground or below ground. So that's step 1.
For example, in my area, they offer the following nominal services:
- Underground: split-phase 240/120 VAC, 3-wire, grounded.
- Underground: split-phase 480/240 VAC, 3-wire, grounded.
- Underground: 3-phase 208Y/120 VAC, 4-wire, grounded, wye.
- Underground: 3-phase 240/120 VAC, 4-wire, grounded, delta.
- Underground: 3-phase 480Y/277 VAC, 4-wire, grounded, wye.
- Underground: 3-phase 480/240 VAC, 4-wire, grounded, delta.
- Overground: split-phase 240/120 VAC, 3-wire, grounded.
- Overground: split-phase 480/240 VAC, 3-wire, grounded.
- Overground: 3-phase 208Y/120 VAC, 4-wire, grounded, wye.
- Overground: 3-phase 240/120 VAC, 4-wire, grounded, delta.
- Overground: 3-phase 480Y/277 VAC, 4-wire, grounded, wye.
- Overground: 3-phase 480/240 VAC, 4-wire, grounded, open-delta.
Others can be requested. But they would be subject to a different approval process with the power company, as well as at the county level, probably.
But as you can see, 480 VAC 3-phase is a nominal service and can be readily provided by the power company.
In my area, there are current/power limitations with respect to the above services. For example, they may not offer 3-phase 480 VAC service unless your need is 50 kW or higher. (Above 100 A, though they do make irrigation pump exception cases for a single motor of at least 20 HP.)
Also, if you are considering using your own conversion system (your own customer-supplied transformer, for example), then my power company would need to pre-approve it before you could use it. Even if it is on your side of the service entry to the home.
If you are considering a fast charging service, of some kind, then there may also be special provisions that are directly related to that specific usage. Often, their tariffs (the rates they charge as agreed by local gov't) may be cheaper (or more expensive) for the specific case of charging up an EV. Usually, it's cheaper. They also may have an experimental program where you allow them to use your EV to temporarily store energy or to recover it, at their control. You'd need to provide them with details about when you want to use the vehicle (a calendar of your usage, in effect) so they wouldn't interfere with your intended uses of the EV. (Some will offer a still steeper discount if you allow that.)
I'm sure there are NEC code requirements with respect to fast chargers for EVs, by now. But fast charging systems in residences is a relatively new activity and it's possible the code is still playing catch-up in your area. Just be aware that there are fire risks unique to this situation. They may affect your home fire insurance policy, too. Make sure everyone is on the same table when considering the right way to get this done.
Telsa has a special group that you can get into contact with. I have their number, but I probably shouldn't give it out here. They are highly technical and they can answer most questions with respect to their 480 VAC charging stations. Make absolutely certain that you contact them and ask them to help you work with your local power company as well as with a local electrician who has the right skillsets to make this happen, correctly. (Most electricians will not have adequate experience in this area because so few residences are setting themselves up, this way. -- Except perhaps in California where you may have better access to appropriately trained electricians.)
And yes, I know it is possible to consider a Tesla Supercharger in a residential home situation because I've had this exact conversation already with my local power company specialists. It's not a slam-dunk. It will take some time on their part to consider how it may be done and if it may be done, at all, as they also need to look at their entire system leading up to my home for its capacity and my proposed demand requirements. If I do decide to move forward, then they will take the time to evaluate their own system and their staff's willingness to support providing that service directly to my home. And I'm told that until they check things out, it's not a sure thing. But they didn't discourage me, either. So it appears the door is open, at least here, for the Tesla supercharger system. But Tesla doesn't expect many residential installations and the power company doesn't, either. For the most part, it's expected mostly to be used in a more commercial setting. (Check with Tesla for availability when purposed for a residence.)
The upshot of all this is that you need to involve all interested parties and make sure that everyone is on the same page about what is to be achieved and how it can be safely achieved.
Asking here is not a means of avoiding any of that. Even if you get really good information that helps you get closer to understanding your situation, you still need to involve all of the appropriate groups. There are many ways this can go wrong and the amount of power and size of the energy transfers are unusually large and therefore deserve the best informed attention you can muster for the project.