VFD Fan?

A

adam britz

Joined
Feb 16, 2017
Messages
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For those of you who run vfd on your grinder. Do you use a fan to keep vfd cool? I am assuming you have it enclosed in a sealed container to protect it from metal dust, etc., so how do you keep it cool, or is it not needed?
Thanks as always for any help.
 
Me Too^^^^like Don no Fans....Mine are KBAC different sizes in NEMA enclosures...I have read that those not in NEMA enclosures need some air flow.
 
I have a KBAC-29 1P and no Fan. The back of the case does have some heat sink fins built into the case, I have never noticed it getting hot.
 
Keep in mind, the VFDs in NEMA enclosures are designed to run without a fan. An open unit may need a fan ( with filter of course) to keep it cool inside an enclosure. Or, it may be ok without a fan, if the enclosure is large enough. Only real way to tell is put it in an enclosure and take temp readings. Sounds like a pain right? That's why I went with the kbac.
 
If running a VFD in an non NEMA-4 enclosure, then putting it in a larger enclosure with a filter on the top and a fan on the bottom works well. Have the fan facing so the airflow is out of the case ( drawing the air in through the filter. A small computer cooling type pancake fand works well.
 
A NEMA 1 enclosure will keep your fingers out, but not dust

A NEMA 4 will keep out dust and it's engineered to be sealed by heat sinking to the outside case

Just buy a KBAC-27D and use it.

by the time you make up a fan filtered enclosure you have a bulkier more fragile setup for not much $ actually saved.
 
Stacy E. Apelt - Bladesmith said:
If running a VFD in an non NEMA-4 enclosure, then putting it in a larger enclosure with a filter on the top and a fan on the bottom works well. Have the fan facing so the airflow is out of the case ( drawing the air in through the filter. A small computer cooling type pancake fand works well.
Click to expand...
For good measure suspend a few neodymium magnets within enclosure in the airflow.
You might be surprised the crap what gets thru.
 
I had some rare earth magnets in the shop in a zip-lock bag. It was on a shelf away from the grinder. I picked it up one day and went to knock off the dust on the outside. Some of it didn't come off ... because it was superfine metal dust attracted to the magnets.
 
This is why it is worth the money to buy VFDs that come in a NEMA 4 enclosure. The enclosures are designed with proper heat sinking assuming they are mounted more or less in the open air. The drive failing due to dust won't be an issue. The drive failing because a $10 fan fails won't be an issue.

I just had to replace an open VFD on a very expensive wood lathe. It was in a nice little ventilated metal box, and we would blow the dust out every so often. But it eventually failed and when I removed the drive I discovered that there was a little tiny muffin fan hidden in the back of the drive to blow air over the heat sinks. Of course the fan had failed which probably started the drive on the way to failure. I would have gladly paid a few hundred dollars more when buying the lathe for a sealed drive, using an open drive on a piece of machinery that produces any kind of dust is just dumb IMO. The down-time and labor to eventually replace an open drive will cost more than the extra money it will cost to buy a NEMA 4 drive in the first place. FWIW I've been very happy with the KBAC drives.
 
a basic IP20/NEMA 1 enclosure should be fine if mounted above and to the side of your grinder. my TECO vfd's have built in fans with thermostat control. a small piece of filter over the fan inlet is all you need. My Leeson Speedmaster has a very large heat sink attached. even in heat of summer after being on for hours, the heat sink is never above ambient temperature. you want NEMA 4, go for it. I went IP20 and spent the difference for a new bench top drill press.
 
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