Should a VFD always be in an enclosure?

here is what my vfd setup looks like..
[video=youtube_share;Ja5CZHVRM8U]http://youtu.be/Ja5CZHVRM8U[/video]

My vfd doesnt run hot the way it is moounted in the enclosure, I do plan on adding a filter on the bottom and a fan in the top corner to create a cross flow to make sure it doesn't overheat if i'm running hard.. my tig welder doesnt mess with the vfd the way it is..
 
Nelson:

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?)
Yes, that is correct, that is a 2-pole switch breaking L1 and L2 of the main feed to the VFD
Then you have a BX box with two conduits coming down- (watertight conduit?). One goes to the motor no doubt.
Correct, one directly to the motor, remember no switches between the VFD and the motor.
Does the other go to a remote control box?
It goes to the drum switch with is original to the machine, I just rewired it for low voltage.

I posted some close up pics in this thread: http://www.hobby-machinist.com/show...e-off-forward-switch-to-vfd?p=26771#post26771
 
Kenny,

Looks like you used shielded 4 or 6 connector 18 gauge wire from the VFD to the drum switch.

When you "break" the two lines to the on/off switch, as in Jim B's example, do you do that before the VFD, because you arent supposed to have switches between the motor and VFD.


Nelson
 
Allthumbz said:
Kenny,

Looks like you used shielded 4 or 6 connector 18 gauge wire from the VFD to the drum switch.

When you "break" the two lines to the on/off switch, as in Jim B's example, do you do that before the VFD, because you arent supposed to have switches between the motor and VFD.


Nelson
Click to expand...

It is #18 shielded 3 conductor, Black, White and Red. The Green wire is soldered to the shield under the heat shrink and then grounded. You only need 3 wires to each "remote" function. The wire type here is not critical, so use whatever.

Yes, the switch breaks the main feed TO the VFD, Is #12-2 wire on a 20 amp 240v circuit.
 
Mr. Nelson;

As far as cutting holes in a electrical enclosure. I see you list a drill press and two mills in your shop. Put them to use. If I am correct, they will put any size and shape hole anywhere you want at any time you want.
 
Nelson said:
Kenny,

4 or 6 connector 18 gauge wire from the VFD to the drum switch.

Nelson
Click to expand...

Please guys, I don't understand. Why do you insist on using a drum switch when the VFD provides the reverse function. The Drum switch is not UL approved as a disconnecting device either. Just deep six it, make it simple. Remember the KISS principle. A toggle switch is not approved as a disconnect either unless horsepower rated. Most aren't unless you get the $10- $12 models, which I doubt. Just get a motor rated switch with ears for a padlock on the cover, or some other lockable device. Mount it as the first device in the circuit and then USE IT.

Engineers and code designers, the last time I checked, don't spend their time writing requirements and instructions for their health. There is a good reason apprently way over our heads. YES, AN ENCLOSURE IS REQUIRED WITH A VFD UNLESS SPECIFICLY STATED TO BE OMITTED. I only know code, not the reasoning behind it. Have a good day, and be SAFE.​ Is your or someone elses life worth that extra $10?
 
rdhem2 said:
Please guys, I don't understand. Why do you insist on using a drum switch when the VFD provides the reverse function. The Drum switch is not UL approved as a disconnecting device either. Just deep six it, make it simple. Remember the KISS principle. A toggle switch is not approved as a disconnect either unless horsepower rated. Most aren't unless you get the $10- $12 models, which I doubt. Just get a motor rated switch with ears for a padlock on the cover, or some other lockable device. Mount it as the first device in the circuit and then USE IT.

Engineers and code designers, the last time I checked, don't spend their time writing requirements and instructions for their health. There is a good reason apprently way over our heads. YES, AN ENCLOSURE IS REQUIRED WITH A VFD UNLESS SPECIFICLY STATED TO BE OMITTED. I only know code, not the reasoning behind it. Have a good day, and be SAFE.​ Is your or someone elses life worth that extra $10?
Click to expand...

In my case, the drum switch is just used as a low voltage switch to remotely control the VFD, and that is the way most are used in conjunction with VFD's. As to why we use them? Well sir that is simple....they are already on most machines when we get them and they work perfectly for the purpose.

Nowhere in my VFD manual does it say that an enclosure is "required".

You sir need a little more tolerance and accept the fact that there sometimes is indeed "two ways to skin a cat", your way is not the only way sometimes. Dredging up one year old posts to try to get your 2c in is not going to make any friends around here.
 
I built an enclosure with a fan and filter for my FM50 because my shop is too small to have a separate cutting/grinding room. There is metallic (conductive) dust everywhere. That is notoriously bad for anything electronic. The front of the VFD is visible through a lexan window. Control is done with remote inputs.

There doesn't seem to be much advantage to an enclosure if the front is open, unless the fan is blowing in (positive pressure, blowing out around the face). That is contrary to the diagrams in the FM50 manual.
 
I apologze Mr. KennyD. My limited knowledge only comes from operating a shop building custom electrical enclosures and control wiring under UL supervision for 32 years. Just because it works does not mean it is right. Silly codes and rules.
 
rdhem2 said:
I apologze Mr. KennyD. My limited knowledge only comes from operating a shop building custom electrical enclosures and control wiring under UL supervision for 32 years. Just because it works does not mean it is right. Silly codes and rules.
Click to expand...


Easy there big guy. Enclosures are rated for different enviroments that the equipment will be used in. Some are for wet enviroments while others for dusty or areas where fumes causing explosion hazards exist. It is good advice to use some type of enclosure when the possibility of metal chips or moisture is a concern. Also the point of covering the terminals is a good idea. Thats why the same drives are available in different rated housings. You analyze the site conditions and pick the right type to begin with. It may be good for your business but not every situation requires an enclosure. Most manufactures specify four times the area for sizing an enclosure for heat dissipation.
Darcy
 
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