Should a VFD always be in an enclosure?

HMF

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Home Depot no longer carries a 6x6 enclosure that I wanted to use for a VFD.
I can get one elsewhere, but I want to know if you guys think an enclosure is a must
because then I may need a fan to keep the VFD cool, right?

What size do you guys recommend? I thought 6x6 NEMA was what I needed?
Also, how do you cut the holes for the face of the VFD to go though?

Thanks,


:tiphat:Nelson
 
Hi Nelson

For a VFD enclosure, if I remember right, has to be 4-times the size of the VFd
A 6x6 sounds kind of small. Any of the boxes out there would need ventilation somehow. I have a 7.5hp and a 5hp Teco FM500 models, not the fm50. But they both came in enclosures, the enclosures are very large, and have vents all over them, with built in fans. Your VFD manual might suggest what size is proper for your VFD.

As for cutting the holes for the face, you could measure it out, drill holes in the corners, then jig saw the rest. There was a VFD install thread here a few days back, where the guy added a air filter to the enclosure too, I thought it was a good idea. More importantly, make sure its vented well enough not to cook your VFD, and make sure it has some thing to keep chips out. Mine look like they have a screen behind the vent cut outs.

Paul
 
Mine is just on the wall, out of the way from coolant or flying chips. A enclosure is not "needed". I can't see how 6x6 would be big enough anyway?

IMG_1051.jpg

IMG_1051.jpg
 
Nelson,

Paul and Kenny made valid points above.

Not sure about what you are planning but the VFD that I have came without a NEMA enclosure but install instructions called for one. I asked an electrical engineer buddy about it. He pointed out that the wiring connection points for my VFD do not meet code without the enclosure. The bare connection points can be reached with a small pointed object. If I remmenber correctly the 4 times size with a fan sounds about right.

Benny
 
If you think you have any chance of dust, chips, or coolant getting to your VFD, you can allways build a small cabinet made of wood to put it in. Gives you the option of size, vent location, and options for mounting the fan if used.

One of my Teco FM500 units are mounted on he wall, and I glad it has the nema enclosure. I find chips sitting on it all the time. But my shop is a 1-car garage, and very congested.

I built a wooden enclosure for the service panel in the basement last week. I used 1/2 thick materials. Picked the wood up at home depot, they even cut it all to size for free. A few hinges, and a package of screws, and less than a hr later, It was done!

Just another idea for you

Paul
 
Mine is just on the wall, out of the way from coolant or flying chips. A enclosure is not "needed". I can't see how 6x6 would be big enough anyway?

View attachment 33694

Kenny,

That is a very neat setup, but I have a couple questions.

You have one conduit coming into a flip switch- is that the power going in? (220?)
Then you have a BX box with two conduits coming down- (watertight conduit?). One goes to the motor no doubt.
Does the other go to a remote control box?

Thanks!

Nelson
 
I would definitely run an enclosure. NEMA covers many types of enclosure, depending on the environment the equipment will operate in. If you run a fan, and I would, make sure you have sufficient inlet area to allow flow commensurate with the capacity of the fan, plus an allowance for the filter restriction. I wouldn't hesitate to use an 8 x 8 x 4, or even larger. You also will probably need to build a power supply for the fan, unless you are planning a 110/120 VAC muffin fan. That would be preferable, but not always easy to find. Ebay I guess.

I have run a totally sealed metal Hoffman enclosure, with a large Variac running 2 500w cartridge heaters. The fan was mounted on standoffs to blow down over the Variac. Doing this without vent simply dissipated the heat over the entire enclosure by warming up the air inside to an even temperature. Monitors showed it operating within design parameters, even in 110 ambient. Plus, it was sealed against ingress in a corrosive atmosphere, both in a fertilizer packaging plant, and Morton Salt packaging operations.


For reference:

http://www.nema.org/prod/be/enclosures/upload/NEMA_Enclosure_Types.pdf
 
Paul,

I bought a 12x12 NEMA at HD a while back when they had them- cost me about $25. But it looks so large next to a VFD.
The box has a cover somewhere, but I would likely cut a piece of acrylic plastic, so I could see it.
(see pix)
View attachment 33700
Also bought a Murray 2-wire disconnect- I think it is 30 Amps at HD.
View attachment 33702View attachment 33703

The original pushbuttons are shown in the NEMA.
View attachment 33701
The main house panel is also shown- I need to upgrade to 200A and a bigger panel.
The electric service is in an alcove where I shove the small mill (Burke #4).
View attachment 337050View attachment 33704

My tiny shop area is right near the service which is good.
I figured I would have the sparky upgrade the service and box, hook up my new basement lines and install 2 or 3 220V 30A lines for the machines.

Nelson
 
Mine is set up just about like Kennyd's. I saw no need for an enclosure in my situation.
Bobby
 
Adding photo and note

Nelson,

Paul and Kenny made valid points above.

Not sure about what you are planning but the VFD that I have came without a NEMA enclosure but install instructions called for one. I asked an electrical engineer buddy about it. He pointed out that the wiring connection points for my VFD do not meet code without the enclosure. The bare connection points can be reached with a small pointed object. If I remmenber correctly the 4 times size with a fan sounds about right.

Benny

Nelson's post with photos reminded me that my buddy also gave me a NEMA enclosure that was a take-off modified to let the drive controls stick out. I plan to add plexiglas to keep it clean inside as my drive is much smaller.

Benny

NEMA - VFD 002R.jpg
 
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