110.26 Depth of Working Space

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tbassler_99

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I am currently designing an enclosed pump/filter skid module

I have a pretty tight space with a control panel that encloses (3) 480V VFD's. The front of the panel has some 120V indicator lights on it and 120V selector switches.

The panel is 18" deep and I have a clearance of about 40" from the front of the panel.

When the panel is opened, I have about 44" clearance from the front of the 480V VFD's.

110.26 (A)(1) says distances shall be measured from the enclosure or opening if live parts are enclosed.

Does this mean I need 42" front he front of the enclosure too? I am not sure if I meet Condition 1 of the accompanying table. The live parts are not really on the front of the plastic VFD enclosure but in the back.
 
Measuring from an enclosure means: Close the panel door and measure to your opposing obstacle. So 40" here.

It doesn't really matter how the components are arranged inside the enclosure. You still measure from the front of the enclosure.

The three conditions are based upon the opposing obstacle.
 
Enclopsure inside an enclosure?

Enclopsure inside an enclosure?

So if the VFD were mounted on the wall, I would be OK, but since it is inside a panel, I need extra distance?

It still seems like I am satisfying the requirement of clearance. There are no exposed live parts on the VFD, it has it's own enclosure.

Oh well I sure wish my mechanical would've taken my 42" clearance requirement more seriously when I said it months ago.
 
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