Don't take this the wrong way, but you should have asked for advise before ordering that if you don't know anything about PSUs.
Return it and order something made by quality manufacturers like Seasonic, Superflower, Flextronics, or Delta. Most brands like Corsair, XFX, EVGA, Silverstone, etc just slap their names on PSUs made by the previously mentioned manufacturers. It's hard to tell what's what, so I suggest browsing through
www.jonnyguru.com for the best and most in depth psu reviews on the net.
Look up "gutless wonder" on that site. That's what you just bought, unfortunately. I'd be surprised if that PSU can't put out half of it's rated power continuously without dying. I give it 2 days before it crops out on you running a single stock S3.
PSUs used for mining are put under heavy stress, 24/7. You can't skimp out.