The PSU has more than enough capacity on the all important +12V rail. It is also made by a reputable OEM, Delta Electronics Inc. so it is able to deliver the power specified on its label.
The reason I ask what the specific brand and model number of the graphics card is, is to determine whether or not the graphics card will require a 75-Watt 6-pin PCI Express supplementary power connector since the 280W PSU will, most likely, not have one.