X5304 and 72v/40A controller problem

[disndat]

Hey guys so I just switched my rear motor to a 20" and got another 24v battery to run at 72 volts.I hooked everything up as normal and went for a little spin around my parking garage.Everything was fine until I stopped for car to pass by and then lightly hit the throttle and puff nothing-power to the controller is dead.So usually this means Ive blown a fuse on one of the batteries and I replace it and everything is fine-but Ive blown 2 fuses and when I replaced them they just blew right away.So I figure that the controller is blown so I take out the controller and open it up to look at it.Nothings burnt and no obvious sign of shorting.So I close back up and one by one I hook it up to each of my 24v batteries and the controller comes on and seems fine-the motor is not hooked up at this point.So then I hook up one battery and plug in the motor and hall sensor and pop-the controller goes dead.So then I hook up just the battery and the hall sensor and everthing comes on.So what do you guys think-is the controller blown or the motor connection fried?Also is there anyone in Toronto that has experience with this stuff or should I just send it back to justin in vancouver?

Thanks
Chris
Edit update-So I opened the controller again and its definitely fried-I found a chip off one of the fets rolling around inside the case and it stinks of electric burns.So my question now is this-Is the motor fried as well or should it be fine?

 

[billvon]

So I opened the controller again and its definitely fried-I found a chip off one of the fets rolling around inside the case and it stinks of electric burns.So my question now is this-Is the motor fried as well or should it be fine?

Motor should be fine. About the only things you can do to it are:

-exceed the Curie points of the magnets and demagnetize them (unlikely; you have to get it very, very hot)

-physically melt the windings (unlikely unless there was a lightning strike involved)

-damage the Hall sensors by reverse biasing them or something (probably didn't happen by your description)

The controllers are much more likely to blow. I've blown two of them so far; was able to fix one.

 

[Jozzer]

All the answers you need are here...
http://endless-sphere.com/forums/viewtopic.php?t=764

 

[echoppershop]

Ya, odds are, the motor is fine...

...BUT, I have a friend who melted all the motor leads running 72V and 40A... now that could have been an isolated incident and it was a modified controller, but since then, I've never used more than the Crystalyte 35A 36-72V controller. At 72V with 35A controller, the Phoenix brute was stupid fast when I tested it.... and then I had to tighten a bunch of spokes, lol, which is why if I use such a powerful setup again, I'll fit the hub into a billet wheel and be done with the spoke twisting, lol.