Working Clearance

[pete m.]

This is a hypothectical question that I'm looking for opinions on.

If there are two panelboards mounted side by side on a wall that measures 50 inches in width and one panelboard has a depth of 6" and the other has a depth of 8" would this constitute a code violation?

Pete

 

[augie47]

The difference in depth would not constitute a violation.

 

[pete m.]

The difference in depth would not constitute a violation.

From a practical standpoint and safety standpoint I agree with you 100%. I'm just not sure the code verbiage agrees with either of us.



(2) Width of Working Space. The width of the working space in front of the electrical equipment shall be the width of the equipment or 762 mm (30 in.), whichever is greater. In all cases, the work space shall permit at least a 90 degree opening of equipment doors or hinged panels.

Pete

 

[Cavie]

No inspector in his right mind would gig you on that.

 

[augie47]

Pete, I had to re-read it a number of times, and you very well may be correct, depending on the width and location of the panels within the 50" width.
The 30" required by 110.26(A)(2) would need to be maintained for each panel since they are separate depth.
Kudos to you.

 

[iwire]

I think Pete is right.

As far as any inspector 'giging' us on it I thought this was an NEC web site where we talked about the rules and not what we can get away with.


I would shim out the shallow panel, I have had to do this when placing a 7" deep panel beside a 16 - 18" deep transfer switch.

 

[charlie b]

Presuming the panels are each 22 inches wide, even if you install them as far apart as you can along that 50 inch wide wall, the 6 inch deep panel will not have more than 28 inches of clear space, before encountering the deeper panel. I infer that you used the value of 50 inches specifically for that reason. I agree with the others who would call this a violation. I like Bob's solution to the problem.

 

[mcclary's electrical]

Are dedicated space and working space the same thing? If so, can't you call the larger panel "associated equipment",,,,that is not foreign to the installation as a whole?

 

[charlie b]

If there are two panelboards mounted side by side on a wall that measures 50 inches in width . . . .

Of course, if I really wanted to be picky (who, me? :grin, I would mention that we can't answer the question without knowing what is on the other side of the 50 inch width. If there are side walls at both ends, then the previous answers hold true. If one side or the other of this 50 inch wall opens up to another room, then perhaps there is working clearance available on that side of the wall.

 

[charlie b]

Are dedicated space and working space the same thing? If so, can't you call the larger panel "associated equipment",,,,that is not foreign to the installation as a whole?

That was actually my first thought - that there is an allowance of 6 inches that one electrical item can impinge on another's clearance space. But I read the article again, before I typed my earlier answer.

"Dedicated space" has to do with the area above and below a panel. That space is dedicated to the installation of conduits, and that is why we can't have pipes or other foreign systems in that space. The issue at hand has to do with something to the side of a panel. There is no 6 inch allowance in this part of the rule.

 

[qcroanoke]

I think Pete is right.

As far as any inspector 'giging' us on it I thought this was an NEC web site where we talked about the rules and not what we can get away with.


I would shim out the shallow panel, I have had to do this when placing a 7" deep panel beside a 16 - 18" deep transfer switch.

I have done that very thing many, many times.

 

[cowboyjwc]

Wow, this is an interesting one, has an inspector whose pet peeve is working space, I would probably not call it. I've always considered that if it was two panels that were 22" wide then the width of the equipment was 44", I never looked at them as two seperate pieces.

But, as said before, code wise I would have to agree that it's a violation.

 

[mcclary's electrical]

That was actually my first thought - that there is an allowance of 6 inches that one electrical item can impinge on another's clearance space. But I read the article again, before I typed my earlier answer.

"Dedicated space" has to do with the area above and below a panel. That space is dedicated to the installation of conduits, and that is why we can't have pipes or other foreign systems in that space. The issue at hand has to do with something to the side of a panel. There is no 6 inch allowance in this part of the rule.

I tried to seek clear definitions of both dedicated space vs working clearance, but you summed it up beautifully. Thanks

 

[WastefulMiser]

In my opinion it would work if you did it like this:

Wall 1 >> 22"W 8"D PB 4" from Wall 1 >> 4" space bewteen PB's >> 22"W 6"D PB >> Wall 2

That would leave you with a 30" bubble from left edge of the 6"D PB to Wall 2.

 

[charlie b]

Wall 1 >> 22"W 8"D PB 4" from Wall 1 >> 4" space bewteen PB's >> 22"W 6"D PB >> Wall 2

4 + 22 + 4 + 22 = 52. The wall is not that wide.

 

[pete m.]

Now for the part that confuses me...

This is an excerpt from the 2008 NEC Handbook commentary;

The 30-in. measurement can be made from either the left or the right edge of the equipment and can overlap other electrical equipment, provided the other equipment does not extend beyond the clearance required by Table 110.26(A)(1).

If I am reading this commentary correctly, using the same 50" wide wall space, I could have a section of switchgear that is 34" deep next to either of the panelboards and not have a violation

Pete

 

[mcclary's electrical]

Now for the part that confuses me...

This is an excerpt from the 2008 NEC Handbook commentary;

The 30-in. measurement can be made from either the left or the right edge of the equipment and can overlap other electrical equipment, provided the other equipment does not extend beyond the clearance required by Table 110.26(A)(1).

If I am reading this commentary correctly, using the same 50" wide wall space, I could have a section of switchgear that is 34" deep next to either of the panelboards and not have a violation

Pete

Yes, the left panel can be right against the corner if need be. You don't need to be centered in that 30" you just need 30"

 

[WastefulMiser]

4 + 22 + 4 + 22 = 52. The wall is not that wide.

Make it 2 + 22 + 4 + 22 = 50 then.

Nonetheless, the standard panelboard width I am used to dealing with is 20" wide.

 

[pete m.]

Yes, the left panel can be right against the corner if need be. You don't need to be centered in that 30" you just need 30"

I agree with what you say but the commentary leads me to believe that the switchgear section could be within the 30" width required for the panelboard as long as it didn't extend beyond the working clearance required by table 110.26(A)(1) for the panelboard.

I know that commentary isn't enforcable but I'm trying to understand the logic (if there is any) in that portion of the commentary.

Pete

 

[mcclary's electrical]

I agree with what you say but the commentary leads me to believe that the switchgear section could be within the 30" width required for the panelboard as long as it didn't extend beyond the working clearance required by table 110.26(A)(1) for the panelboard.

I know that commentary isn't enforcable but I'm trying to understand the logic (if there is any) in that portion of the commentary.

Pete

It would be physically impossible for it to be " within the 30" without extending into the working clearance demanded by 110.26 (a) (1)