Broke my VFD :(

[Burchtree]

I have a Motortronics CSD series AC inverter that I'm using to run my siemans 2-HP 3-phase motor. I had mine plugged in (but not running) while I was vacuuming around it a couple of nights ago and got a loud "pop" and now it is dead. I pulled that sumbitch apart last night and took the fuse out, but not sure if it is good -- I'm so voltmeter-inept, I can't tell if they're blown unless I can see through them.

I did find a piece that had a little chunk blown out of it. Nothing looked burnt, and it may have been something that was there before, but it is weird.

Here is a pic of the broken piece I speak of:

Any suggestions?

thanks all --

 

[Burchtree]

brought my fuse and voltmeter to work, and my buddy says the fuse is dead --- still wonder what that piece that random piece is.

 

[jhiggins]

That is most-likely some thermal-transfer paste the manufacturer put there to keep that component cool. It helps transfer heat out to those cooling fins. Call me if you need to, Michael.

 

[Burchtree]

Oh, I'm gonna.

 

[Mark Williams]

Cant tell about the component on the bottom, but the transistor on the top is easily replaced if it's blown. If you check the legs of the transistor out of circuit and they are shorted together, replace it. Most likely it went bad and took out the fuse. If'n you get desparate. Send it to me and I'll try to fix it.

 

[Burchtree]

Thanks for the offer -- I may have to do that. The folks at the Practical Machinist place thought it might be an inverter or something.

 

[pso]

Hello Micheal

Which model of Motortronic drive do you have? Please confirm that when your drive "went pop", it had the input voltage connected but the output was not turned on. Were you vacuuming around the enclosure of the drive or just in the general area?

The part indicated by the upper red arrow could be one of a number of different types of transistors, a diode or an IC of some sort. It is difficult to tell since I cannot see how many legs it has. Can you have a really close look and post what is printed on the front face of that part, line by line.

It is not clear what the lower red arrow is pointing at. There appears to be a fine white line printed on the board around a black object indicating that it was meant to be on the board. If it is the "little chunk blown out of it", does it fit on the device on the heatsink? If not, try to find where it came from. All the parts should have smooth surfaces and edges with no jagged holes. Also, look for fine cracks in the bodies of the transistors, diodes and IC's (usually devices with black plastic bodies and fine printing on them).

Please post any other pictures that you may have. If you have one of those light boxes for taking pictures of knives, you may be able to get a picture that shows more detail and less shadows. We have the same problem here at work when trying to document blown up boards.

You probably have fuses that are about 1 1/4 inch long and about 1/4 inch in diameter and have a dull, white or grey ceramic body. To check the fuse, set your meter to the Ohm. The meter should read something like "overload". Take the two meter leads and short them together. The meter should read less than 1.0 Ohm. Put one lead on each metal cap of the fuse. The meter should still read less than 1.0 Ohm. If not, your fuse is dead.

Regards,

Phil