Update on transformer....
It would seem that the power adapter that I purchased is only rated at 45watts with the Porter Cable drawing a lot more not sure exactly how much but obviously a lot more than 45 watts. It was the term VA that threw me as it seems to be a reference to the wattage, so without checking first I used the PC for about 10 minutes before the transformer blew. If anyone gets one from this site get the higher rated ones which dont work out much cheaper than a builders transformer which I have bought for at a pretty reasonable £40. The only benefit is you dont have to change the plug.
Lesson learnt....
check power consumption first..
Oh and by the way, I' very pleased with the results of my polishing too.