[Splint]

Hi Guys,
I'm a little disapointed tonight as I was setting up and bench testing a 2010 drive and everything was going well intill I put motor power (plugged in the j3 connector) and turned on the power. There was a crackle and pop as a capacitor blew and a puff of smoke. In my haste I quickly looked at my wiring and documentation and it looked to me like I wired the supply terminals reverse polarity so I pulled the wires off the power supply and layed them on the bench and had a closer look at the documentation. I went to rewire it and questioned myself as to whether it really was reverse polarity in the first place but I couldn't recall exactly how it was wired.
My question is this, if it was in fact wired correctly in the first place is it possible that with the power supply I am using which is the internals of a small mig welder which has been rewound to put out 47 volts dc and i'm not sure how many amps, but plenty, could there have been an arc on the drive which caused it to fry? BTY There was no activity from the motor while this happened.
At this point I have established that the motherboard (optoisolated) is ok and the encoders are working with the tuning software (with a different drive), but I'm a bit gun shy about hooking up another drive to the power supply for fear I may repeat the same thing again. The default setings were used as recommended in the documentation. Any suggestions?
Is it worth hooking up an inline fuse between the power supply and the j3 connector?

Cheers
Splint