110.26 Clearance from gear to entrance

[jfrog]

I've got an electrical room with 480V gear. It falls under the category of Large Equipment. I've got panelboards on the opposite side of the room, so my Table 110.26(A)(1) Working Space is Condition 3, or 4'. The depth of the working space is twice what is required by Table 110.26(A)(1).

What is my required distance to the entrance (door)? See attached PDF. Per 110.26(C)(2), "a single entrance shall be permitted...located such that the distance from the equipment to the nearest edge of the entrance is not less than the minimum clear distance specified in Table 110.26(A)(1) for equipment operating at that voltage and in that condition."

It seems like "that condition" would refer to the condition of the gear with respect to the entrance, which would be Condition 2 (3.5'), not the condition of the room as a whole, or Condition 3 (4').

Does this interpretation gibe with others experience?

 

[don_resqcapt19]

In my opinion this applies to your installation.

... A single entrance to and egress from the required working space shall be permitted where either of the conditions in110.26(C)(2)(a) or (C)(2)(b) is met.
(a) Unobstructed Egress. Where the location permits a continuous and unobstructed way of egress travel, a single entrance to the working space shall be permitted.
(b) Extra Working Space. Where the depth of the working space is twice that required by 110.26(A)(1), a single entrance shall be permitted. It shall be located such that the distance from the equipment to the nearest edge of the entrance is not less than the minimum clear distance specified in Table 110.26(A) for equipment operating at that voltage and in that condition.

 

[Ohm2]

It seems you’re dealing with Condition 3 for the working space (4' depth) due to panelboards on the opposite side of the room, but when determining the distance to the entrance per 110.26(C)(2), the condition of the equipment relative to the entrance could indeed be interpreted separately. "That condition" should refer specifically to the condition between the equipment and the nearest edge of the entrance, which could be Condition 2 (3.5'), assuming there's grounded metal or exposed live parts opposite the gear near the entrance.

 

[Elect117]

Condition 2 as the minimum distance to the door to answer the question. But your interpretation is a little off. It is saying that the doors location must be within the double space. So for your gear, the double space is 8ft down the whole piece and within that, at a maximum of 3'6" the door should be put. So that when you are leaving in a hurry, the door is in the "clear" space and path of travel.

2 things of importance

1) Entrance to and Egress from the Working space
a) Depends on your code cycle (Changes made in 2023)
b) if there is a meter that swings to the wall and requires a 90° clear working space (you might need to offset the gear by 6in or so to adjust)
c) Whether side access is required
d) where there is venting / replaceable filters on the back or side

2) Listed panic hardware (push bar to open) and door opening outward.

 

[don_resqcapt19]

Condition 2 as the minimum distance to the door to answer the question. But your interpretation is a little off. It is saying that the doors location must be within the double space. So for your gear, the double space is 8ft down the whole piece and within that, at a maximum of 3'6" the door should be put. So that when you are leaving in a hurry, the door is in the "clear" space and path of travel.

2 things of importance

1) Entrance to and Egress from the Working space
a) Depends on your code cycle (Changes made in 2023)
b) if there is a meter that swings to the wall and requires a 90° clear working space (you might need to offset the gear by 6in or so to adjust)
c) Whether side access is required
d) where there is venting / replaceable filters on the back or side

2) Listed panic hardware (push bar to open) and door opening outward.

What are you seeing that requires the application of 110.26(C)(2)(b) and not 110.26(C)(2)(a)?

A single entrance to and egress from the required working space shall be permitted where either of the conditions in 110.26(C)(2)(a) or (C)(2)(b) is met.

 

[Elect117]

What are you seeing that requires the application of 110.26(C)(2)(b) and not 110.26(C)(2)(a)?

The OP quoted (C)(2)(b) for the question. I was answering that.

 

[don_resqcapt19]

The OP quoted (C)(2)(b) for the question. I was answering that.

I understand...I have the same question for the OP.

 

[Elect117]

I understand...I have the same question for the OP.

I will say, "continuous and unobstructed" is going to be left up to the AHJ. The handbook's examples don't clarify it, but there is one example that shows a bad layout. The door is not directly behind or inline of the working space. The gear is centered to the room and it could be because you have to run around the gear to get to the door. I have never gotten clarity on whether needing to adjust or change directions makes the path non-continuous. Or if that one is not acceptable because you need to run through working spaces to get to the exit rather than having double the working space as room to get away.

In the OPs layout the wall being against the gear could mean you would need to go backwards and change directions to exit. Not just run backwards. Where as if the gear was shifted away from the wall to a reasonable degree, you would have a direct line to exit through.

I have always been on the fence using (C)(2)(a) on design work on new builds. It leaves little for expansions or dry type transformers if needed down the road. Making the room a little bigger than it needs and providing more than one exit is the best method. Typically, I put one door to the exterior for utility access and the other door to the interior. That with some good placement is usually the best method.

 

[don_resqcapt19]

I will say, "continuous and unobstructed" is going to be left up to the AHJ. ....

I can't see how anyone would say that the egress path is not continuous and unobstructed for the installation shown in the drawing. No matter what path is used, you will always have to change directions to get away from the gear if you are working on it.

But as always, the AHJ has the authority to interpret the code language.

 

[infinity]

I can't see how anyone would say that the egress path is not continuous and unobstructed for the installation shown in the drawing. No matter what path is used, you will always have to change directions to get away from the gear if you are working on it.

I agree. I don't see anything that would meet the definition of an obstruction in the drawing.