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VFD vertical mounting or the VFD cops show up?

Clive603

Titanium
Joined
Aug 2, 2008
Location
Sussex, England
Cooling airflow paths and effectiveness can get weird!

Your VFD was designed using the standard rules for proper airflow and effective cooling when mounted vertically. Then tested to verify proper functioning. The makers know vertical mounting works so thats what they advise. There are quite enough other things that can go wrong without potential odd effects due to inadequate cooling when mounted at "that" angle in an enclosure "that" size when the outside temperature is "this" and there is an r in the month.

With a decent cooling fan and enough airflow in the correct direction to simulate the flow when vertical mounted it will almost certainly be OK horizontal. But the operative word is almost. You'd need to simulate it to be sure. Not easy. Heck the makers didn't bother to simulate for vertical mounting. Following the rules works just fine on this level of job.

Buy a proper enclosure or make a box.

Clive
 

JST

Diamond
Joined
Jun 16, 2001
Location
St Louis
The other wild card is temperature controlled fans... They may use the natural convection until the fan is needed. In that case, the thing may heat up faster than expected before the fan kicks in if horizontal, and life may be shorter.

Many VFDs can be used either vertically OR horizontally. If they go to the trouble of saying vertical only, there is probably a reason.

Use an enclosure that allows that.

BTW, if the VFD only fits one way, the enclosure is probably too small and does not meet the size and clearance requirements..

In an enclosure, the heat is first transferred to the air, then to the enclosure, and finally to the air external to the enclosure. That requires a certain minimum area of the enclosure surface. Normally that is a spec in the manual as well, although it may be expressed "indirectly" as a certain clearance all around the VFD.
 

dkmc

Diamond
The responses tell me what I need to know, thanks to all. The fan is the first thing on with power up, full blast. Mount the drive horizontally and it will be fine. Or go thru way more expense and labor to rip out the
old enclosure, replace it with one that's 4" taller, re-install all the wiring, etc. I'll take my chances. It's
a simple old bandsaw. Max current on drive = 12 amps. Highest current draw I've observed at full load =
3.6 amps. I suspect the drive isn't going to overheat. If the NEC or VFD cops show up........I know Nothing!
 

rons

Diamond
Joined
Mar 5, 2009
Location
California, USA
The last box I worked on was 16W x 20H x 8D. Any sizes bigger and they get real expensive.
Probably if you need something bigger then the VFD is the box.
 








 
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