If it's not a retrofit, then there is something wrong with the fixture. Most likely the reason you fried the previous receptacle. You never did say, or possibly, didn't correctly identify the cause of the problem to begin with. And you said it just EXPLODED. Did it actually explode? Or just fry it? Pulling 14.75 amps on a 15 amp recep is not an issue. If I understand you correctly you had a 20 amp circuit, then a 14 gauge wire tapped off it feeding a 15 amp recep?? Or is this backwards from what you had?