110.26 A (1) Working Spaces

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spsnyder

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I have a 480Y/277V ATS that falls under condition 3 (Exposed electric equipment on both sides of the working space) of Table 110.26(A)(1) Working Spaces. I have 47-5/8" from the cover of the ATS and the cover of the adjacent switchgear. The handle to open the ATS sticks out a couple of inches from the ATS enclosure. Am I in violation of 110.26 since I need 48"?

110.26 A (1) Working Spaces states,"....Distances shall be measured from the exposed live parts or from the enclosure or opening if the live parts are enclosed."

The part that confuses me is "or opening if the live parts are enclosed." Does that mean I can measure from the wall of the enclosure with the door open? Thank you for your input.
 
augie47

augie47

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110.26

110.26

"Distances shall be measured from the exposed live parts or from the enclosure or opening if the live parts are enclosed."
 
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spsnyder

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Does that mean I can choose the greatest distance? If the distance from the wall of the enclosure with the door open is 48-1/8" I am fine?

Thanks.
 
charlie b

charlie b

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Yes you are fine. You can take credit for the location of the panel?s enclosure, not counting the door.

But I think you were OK anyway. The rule says ?48 inches.? It does not say ?48.00 inches.? You don?t have to measure to any greater degree of precision (i.e., to eights of an inch) than is stated in the rule (i.e., to full inches). If you used a tape measure that was marked in inches only (not in any fraction of an inch), and if the measurement was closer to the 48 than to the 47, I would call that good. It is not a matter of the measurement being shorter than 48. Rather, the measurement IS 48, because your measurement device is not capable of measuring with any greater precision than just ?inches.?

Some will argue against that philosophy. So here is another. The rule is not ?48 inches.? Rather, the rule is ?1.2 meters.? The fact that the rule shows, in parentheses, that 1.2 meters is about the same as 48 inches does not matter. The way I read 90.9(D), if you comply with the SI units, then you comply with the code. In this case, 1.2 meters equates to about 47.24 inches. So with your measurement of 47-5/8 inches, you have about 0.38 inches to spare.
 
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