110.26(C)(2) Large Equipment Working Space

[ee927]

I have a scenario where two (2) 1200A, 120/208V distribution panels will be installed in a room with only one entrance/exit. The panels are over 6ft wide and will be installed with their fronts facing each other, creating a single working space between them. The setup is identical to exhibit 110.22 of the 2017 NEC Handbook.

It's clear from 110.26(C)(2)(b) that in this scenario, the required working space between the panels in this example is 6ft and that the entrance shall be located such that the distance between equipment to the nearest edge is not less than 3ft. Sketch 'a' is a proposed dimensioned equipment and room layout using exhibit 110.22 as a basis of design.

Referring to sketch 'b' attached, my question is - would the use of double doors instead of a single door be in compliance of the 3ft lateral clearance required for the room entrance since 1 of the 2 doors will always be outside of the "working space" of each distribution panel? Or is the double doors still technically considered a "single entrance" since they are in the same location at one end of the aisle? The goal is to keep the footprint of this room as small as possible, so if code compliant, sketch 'B' will allow for a slight reduction of the room dimensions. TIA!

sketch 'a'
sketch 'b'

 

[ron]

Would the 1st option apply "Unobstructed Egress. Where the location permits a continuous and unobstructed way of egress travel, a single entrance to the working space shall be permitted.".

Seems that there is only one way out and it is continuous and unobstructed, so you might not need double working space.

 

[ee927]

Would the 1st option apply "Unobstructed Egress. Where the location permits a continuous and unobstructed way of egress travel, a single entrance to the working space shall be permitted.".

Seems that there is only one way out and it is continuous and unobstructed, so you might not need double working space.

I agree with you in that the way the code is worded it seems like double working space may not be required. However, the exhibit that I referenced from the handbook shows double clearance being required in this situation.

 

[jim dungar]

Double working space may be required between the lineups regardless how many egress doors are provided. The egress path cannot be decreased when equipment doors are open, so face to face energized equipment cannot be serviced at the same unless even more space is provided.

The two different doors or double width is required so people can still evacuate even if one egress path is blocked. Double width doors doesn't address blocked paths.