Quote:
Originally Posted by MPaulHolmes
1.
Connects B+ and B- in reverse.
I've done this! It's bad! hahaha! It makes a basically short circuit because the mosfets act as a diode from drain to source (which is now + to -! aahhh!!!)
If you were to close the main contactor with B+ and B- reversed, almost instantly the mosfets' legs would blow off! Don't do that! Hmm... Would there be an easy way to prevent that? Maybe a big dang diode somehow? I don't know. Maybe NiHaoMike is right in that case?
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Actually... YES.
There is a way to prevent that.
When the first guinea pigs start assembling and installing their own controllers we document step by step what we are doing and essentially write the DIY how-to step by step instructions for the wiki. We include a bunch of tests after important steps to double check.
This kind of catastrophic error is the kind of thing that I was thinking about. Everyone can help prevent this problem by documenting careful steps and double checking testing procedures to make absolutely, positively, rock solid, extreme confident sure that it doesn't happen.
This is one item that should get checked at least a half a dozen times as someone is installing. The cost of checking and testing extra times is very small. The cost of this mistake is extremely large.
Visually inspecting the wires to be "positive that postitive going to controller positive" is the obvious first check.
I can imagine going so far as to hook up every connection to the controller EXCEPT the traction pack. Then have someone turn on the car "ignition" so the controller will close the main contacter. Then put a volt meter on the cables and confirm that the traction pack voltage polarity is exactly what it is supposed to be. Then turn the car back off before hooking up the final connections.
Anal retentive? Perhaps. In this case it's probably well worth the extra testing steps considering the cost of a screwup.
Hey... I admit that I make plenty of screwups. That's why I work so hard to avoid the biggest and most expensive screwups by asking silly namby pamby questions.
Are you feeling my positive vibes?