As Clive said, a diagram would be best. However I'll risk guessing - if you're connecting the transformer to the mains without a soft start socket, then the inrush current from charging the capacitors may be too high. Also, are those automotive type blade fuses and are they used on the mains or 70V circuit? If so you shouldn't use that type there as they're only rated for 12-24V. To be fair the fuse still seems to have worked... but that's maybe not the point!