Blown VFD

KenH

Well-Known Member
Well, it finally happened. I've been using a NEMA 1 enclosure Chinese VFD for the last 5 or 6 yrs (used several times/wk) and today it finally blew - with a BANG! I pulled apart enough to see metal dust got inside to short across PC board traces and blew a PCB trace and an insulated-gate bipolar transistor (IGBT) in one leg of circuit. Perhaps I could repair the trace and replace the IGBT, but there's also a small SMD diode that's also blown and I'm not sure what it is. I might try it one day - maybe a good winter project?

While the last couple of VFDs I've installed I took time to make a good filter around the air inlets, this one I've never been very careful about dust in this VFD. I've been planning to replace the "slapped on" filter with the type I used on last two VFDs, just never "got around to it" type of thing. It's been working for years so no rush? Well, today it happened. 5 (6?) yrs from a cheap VFD and poor filter installation isn't too bad. I ordered another today and should be here next week. I'll do a better job of inlet filters and maybe it will last 10 yrs? Those things are getting cheaper - I think this one is $60 shipped?

Later
 
I’ve gone through a couple that way. Always entertaining. I’d like to see what kind f box you come up with.
 
So question. How much heat do these generate?

I am assuming that there is a cooling fan with intake and exhaust!

I know very little so trying to picture how they operate!!
 
Did I say anything about making an enclosure? While one would be good it still has to have air flow for cooling - I expect I'll just put good filters over the air inlets like I did the last two VFDs. The one that blew I'd just "slapped" filters over inlets.... and ran it some without filters allowing metal dust to enter I'm sure. At the cost of the cheap VFD and if they last 5 yrs that will be better (for my hobby use) than spending big bucks for a NEMA 4X VFD.

I'd still recommend the NEMA 4X VFD drive for full time knifemakers.
 
Did I say anything about making an enclosure? While one would be good it still has to have air flow for cooling - I expect I'll just put good filters over the air inlets like I did the last two VFDs. The one that blew I'd just "slapped" filters over inlets.... and ran it some without filters allowing metal dust to enter I'm sure. At the cost of the cheap VFD and if they last 5 yrs that will be better (for my hobby use) than spending big bucks for a NEMA 4X VFD.

I'd still recommend the NEMA 4X VFD drive for full time knifemakers.

What kind of filters did you use. I was going to get some filter material and use Velcro to hold it down.
 
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