Blown VFD

[wdd0422]

Hey everybody,

Would hooking the negative side of a braking resistor terminal (There is no resistor installed) to ground cause a VFD to fail catastrophically? I know its not supposed to be wired like that but looking at the board it doesn't look like this is where the failure originated from. Thanks in advance.

Bill

 

[OkiePC]

I'm really just guessing when I say "probably so". I mean if its a 480vac input VFD, there's 678VDC between the DC bus terminals and they're connected to the incoming 3 phase lines through the rectifier section, so yes, that would likely let the smoke out way too fast.