Load center working space width?

[olc]

Apartment load center - do you think a inspector will require that the 30" width of the working space be centered on the panelboard?
In other words - 14" wide panelboard only has a few inches to one side but plenty of room to the other side.
I don't see where it is spelled out that it be centered on the panelboard.
Ref. 2014 110.26(A)(2)

 

[infinity]

There is no NEC requirement to center the panel in the working space.

 

[Carultch]

Apartment load center - do you think a inspector will require that the 30" width of the working space be centered on the panelboard?
In other words - 14" wide panelboard only has a few inches to one side but plenty of room to the other side.
I don't see where it is spelled out that it be centered on the panelboard.
Ref. 2014 110.26(A)(2)

You need 30" width for this piece of equipment, which means 16" beyond its own width. The 16 inches remaining can be all the way on the left side, all the way on the right side, or anything in between. It doesn't necessarily need to be equal 8" on both sides. The space in front of equipment in general needing workspace, is a virtual "refrigerator box", that is 30" wide (or the eqpt width if greater) x (conditionally) 36" deep x 78" tall. If this "refrigerator box" fits in front of the equipment, you have your workspace.

It can also overlap with adjacent pieces of equipment. If you had an identical panel, both could be side-by-side, and the same 30" workspace width can apply to both units. You wouldn't need 60" width in order to dedicate 30" to each unit.

 

[olc]

Thanks for the replies.

 

[gadfly56]

You need 30" width for this piece of equipment, which means 16" beyond its own width. The 16 inches remaining can be all the way on the left side, all the way on the right side, or anything in between. It doesn't necessarily need to be equal 8" on both sides. The space in front of equipment in general needing workspace, is a virtual "refrigerator box", that is 30" wide (or the eqpt width if greater) x (conditionally) 36" deep x 78" tall. If this "refrigerator box" fits in front of the equipment, you have your workspace.

It can also overlap with adjacent pieces of equipment. If you had an identical panel, both could be side-by-side, and the same 30" workspace width can apply to both units. You wouldn't need 60" width in order to dedicate 30" to each unit.

I believe that's only correct where the equipment is of identical depth. If one panel is 4" deep and the other is 6" deep, that won't fly.

 

[iceworm]

There needs to be enough on the hinge side to open the door 90 deg. So, if the space is scrunched up tight on the hinge side, it may need a 1/2" extra.

 

[infinity]

I believe that's only correct where the equipment is of identical depth. If one panel is 4" deep and the other is 6" deep, that won't fly.

That's correct unless you built out the 4" panel to be flush with the 6" panel. Carultch did say identical panels so I would assume that he was thinking that they would both be the same depth.

 

[gadfly56]

That's correct unless you built out the 4" panel to be flush with the 6" panel. Carultch did say identical panels so I would assume that he was thinking that they would both be the same depth.

You're right, he did say that. :slaphead: My brain just skipped right to the general case.

 

[iceworm]

... If one panel is 4" deep and the other is 6" deep, that won't fly.

I understood there was a 6" easement if the equipment is associated with the electrical installation. 110.26.A.3

edit to add
Looked it up - Nope. That is only if the equipment is above or below, not side by side

 

[infinity]

I understood there was a 6" easement if the equipment is associated with the electrical installation. 110.26.A.3

Does that apply to two panels side by side? As silly as it seems I don't believe that it does.

 

[Carultch]

I understood there was a 6" easement if the equipment is associated with the electrical installation. 110.26.A.3

edit to add
Looked it up - Nope. That is only if the equipment is above or below, not side by side

This means to comply with the exact letter of the NEC, you'd have to construct a build-out behind the not-as-deep piece of equipment, in order to make the front faces coplanar, if you want that equipment to take credit for the same 30" of width. By "build-out", I mean a structure to offset the equipment from the wall, such as dimensional lumber cut to a depth matching the difference in depth. The only reason for doing this, is the NEC's omission of specifying any tolerance for dissimilar depths. Equipment itself can vary in depth, and the installer cannot force that to be coplanar.

I get that an entire transformer or HVAC unit, trapping the disconnect so it is a challenge to reach it is a safety hazard. But adjacent equipment up to 6", is no more of a safety hazard on the sides of the equipment under maintenance, than it would be by being below it. The 6" above and below also only mentions raceways and electrical equipment, but not structural features such as a housekeeping slab. It is common for a housekeeping slab to extend a few inches beyond the equipment footprint.