I'm not sure you understand what I am saying. The maximum possible power draw of a power supply is irrelevant. What is relevant is that the SP30 has been advertised as requiring 2500W. Now it turns out it needs 3000W. It is the difference between being able run one, and not. People with access to 220V should be fine, but those limited to 120V won't be. And 220V was never stated to be a requirement; not in the product specs on the Spondoolies website.
If you are under the impression that Spondoolies customers should rely on bitcointalk.org, rather than
http://www.spondoolies-tech.com/ you are mistaken.
I'm pretty sure you can configure it to draw only 2500W, if you have that limitation on the electrical circuits, but it will be at the expense of the hashrate. No one here said you need 3000W to run it. Guy said earlier that the PSUs are 1200W output, 1500W at the wall if you're using 220V. I just read the PSU specifications and the UL certification which corresponds to your case in US .. and I'm translating you what you should understand from them.
The unit will run even on 110V and 10 amps if this is everything you have. But don't ask anyone to guarantee 4.5TH/s with that. You should read the specifications, not the advertisements. They're generic, and do not say under what conditions you get that consumption. The link I gave earlier was from the SP repository, and from the PSU manufacturer, not bitcointalk.org.