Fried a drive tonight....

[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

[Al_The_Man]

Electrolytic capacitors usually blow if Reverse polarity, the supplied voltage is over the rated value, or ac is applied.
Is the power supply suitably smoothed with enough capacitance?
Al.

[Splint]

Thanks for the reply Al,
well reverse polarity is possible, the 47v power supply is well within the 100v 20A limit of the drive and the capacitance is 30,000uF.
I did some other checks to see if the servo motor had a short through the windings or to the housing but everything seems ok there.
Allthough I did make mention of the cap blowing, it looks like damage has been done to a number of parts of the drive (a couple of the chips look to be damaged).
The servo motor is an Electrocraft E543 which has a max terminal voltage of 45v, a max peak current of 12A and a max continuous current of 4.1A.

Cheers
Splint

[rutexus]

Splint,

Which capacitor blew? If it was the electrolytic, you are probably right in thinking you reversed the motor power. That will blow a lot of parts off the drive.

There should be no problem with your transformer. If you measure the DC voltage (VM) with a DC meter and it measures the expected voltage that should be fine. Vladimir recommends a fast blow fuse beteween the motor and drive, but I have not found them to be fast enough to able to protect a drive. It may keep from having a fire, however.

If there is any concern, start out with a lower vm. The defaults that come loaded in the drive are usually a good place to start tuning.

[sendkeys]

You're not alone, Make sure to give rutex a call they helped me out when I blow up my driver.(it was my fault not the drives)

[Splint]

Thanks for your assistance gentlemen, it sounds very much like I hooked up reverse polarity. I'll give Vlad a call on Monday and get another drive and see if he can suggest a good setup for a fast blow fuse.

Thanks again
Splint