1. You do not need 1050W for 3 HD5830 (I am assuming it is for a gaming rig with a low powered, preferably undeclocked and undervolted 1-2 core CPU), 750W will be more than enough with headroom for overclocking.
2. Also look at the brand (very important - your PSU that exploded was probably a chinese no-name/piece of crap.
I recommend this website if you're looking for PSU reviews:
http://www.jonnyguru.com/I want to make it perfectly clear in the first line:
The power ratings listed on the rails are a lie. 20A + 20A + 20A + 35A + 35A + 20A = 150A (or 1800W). The rails must in fact share power load to meet the Labels' own criteria of providing 80A across the entire 12V circuit.
I second this fellows suggestion, though it looks like it is too late. You already ordered one of the crappier units on the market, a rebranded out of date throwback:
"It's another Super Flower unit, you're looking at something inline with the Mach1 1000w but less efficient and a cheaper fan.
It shouldn't even do 80+ standard at full load and isn't even modular.
A skip if you're looking for a 1kw unit. "
Why you would want a possible repeat of your previous experience, buying another "6 rail" PSU is beyond me. Again, most of these rails are in actuality shared load (as the total AMPerage of all 12V rails is only 80A). I can't find specs on the PSU, so if I were you I'd hope that the 20A rail is set for the mobo and peripherals, while the 35A rails are for the PCI-E connectors.
If you can cancel your order and return it for a refund though, I'd highly suggest you do that. 3 5830s will run easily on a 750W which you will end up saving money on if you get even a bronze rated supply like
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371025 (one of my favs back in the day, probably still decent).