2 Exits from Electric room.

[Sparky2791]

NEC110.26 (C) (2) reads For equipment rated 1200A or more and over 6' wide that contains overcurrent devices, switching devices or control devices, there shall be one entrance and egress from the the required working space.......... I have a 1600A switchboard that is over 6' wide because it includes the utility company cable termination compartment and the instrument transfomer section. The distribution part of the switchboard, the only part that contains overcurrent devices, switching devices or control devices is only 3' wide.
Is it possible to consider only one entrance to/egress from the working space , in this case the main electric room, is required since the only portion that contains the OCPD is 3' wide? I cannot arrange the gear to fall under (a) or (b) at the end of that section

Or am I 'grasping at straws' to look at it this way?

I have reviewed this requirement with countless architects and every project they give me a single door swinging into the room, which is another issue all by itself.

Thanks for looking.

 

[Ponchik]

I have not done any 1600A install.

The utility section is part of your switch gear or it is provided by utility that installs next to your equipment?

IMO, if the utility termination cabinet is owned and/or serviced only by utility it may not fall uder NEC jurisdiction.

 

[Sparky2791]

I have not done any 1600A install.

The utility section is part of your switch gear or it is provided by utility that installs next to your equipment?

IMO, if the utility termination cabinet is owned and/or serviced only by utility it may not fall uder NEC jurisdiction.

As always the AHJ has the final decision but I was looking to see if the simple fact the 'overall' equipment length is used when applying this rule or only the width of the section that contains the OCPD's

 

[JoeStillman]

If that was one of my projects, I would say it falls under 110.26(C)(2), but then I would keep reading down to (a) and (b), which say you usually don't really need 2 doors.

I would be more concerned with getting doors that are big enough to rig the board in and out.

Oh, and the door swing. I'd be concerned with that too. Send this to your Architect...

(3) Personnel Doors. Where equipment rated 800 A or more
that contains overcurrent devices, switching devices, or control
devices is installed and there is a personnel door(s) intended for
entrance to and egress from the working space less than 7.6 m
(25 ft) from the nearest edge of the working space, the door(s)
shall open in the direction of egress and be equipped with listed
panic hardware.

 

[Sparky2791]

If that was one of my projects, I would say it falls under 110.26(C)(2), but then I would keep reading down to (a) and (b), which say you usually don't really need 2 doors.

I would be more concerned with getting doors that are big enough to rig the board in and out.

Oh, and the door swing. I'd be concerned with that too. Send this to your Architect...

Yes - agree. In my OP I mention (a) & (b) and about the door swing too.

My concern is the unobstructed exit 'definition'. Attached is the layout. Not sure if this complies with that.

 

[JoeStillman]

Yes - agree. In my OP I mention (a) & (b) and about the door swing too.

My concern is the unobstructed exit 'definition'. Attached is the layout. Not sure if this complies with that.

Looks fine to me.

 

[steve66]

Yes - agree. In my OP I mention (a) & (b) and about the door swing too.

My concern is the unobstructed exit 'definition'. Attached is the layout. Not sure if this complies with that.

No, I think you have to count all 3 sections toward the width. If the termination section shorts, you could have arc flash from all 3 sections, and someone would be trapped in the corner of the room.

 

[topgone]

Yes - agree. In my OP I mention (a) & (b) and about the door swing too.

My concern is the unobstructed exit 'definition'. Attached is the layout. Not sure if this complies with that.

Please check if you are allowed around 50 inches of working space depth considering you have only one access/door. IIRC, you are required to have a 60 inches depth of working space if you have one 1 door and your equipment is over 1200A.

 

[Sparky2791]

Please check if you are allowed around 50 inches of working space depth considering you have only one access/door. IIRC, you are required to have a 60 inches depth of working space if you have one 1 door and your equipment is over 1200A.

I have never heard of that requirement. What code would that be from?

 

[JoeStillman]

I have never heard of that requirement. What code would that be from?

That's 110.26(B)(2)(b). The illustration in the handbook doesn't really help much because the only difference between (a) in exhibit 110.21 and (b) in exhibit 110.22 is that the gear is at right angles to the door in (b) and there are two pieces of gear, which isn't mentioned in (b).

 

[Sparky2791]

That's 110.26(B)(2)(b). The illustration in the handbook doesn't really help much because the only difference between (a) in exhibit 110.21 and (b) in exhibit 110.22 is that the gear is at right angles to the door in (b) and there are two pieces of gear, which isn't mentioned in (b).

View attachment 2558195

Yes familiar with that one. I was referring to the 60" dimension Topgone mentioned above. I do not think Topgone recalled correctly. The most clearance required for the voltage (277/480) would be face to face equipment with a clearance of 4'6" between the equipment.

 

[topgone]

I guess I was talking about another code (IFC). The required elbow room of 30 inches needs to be doubled when you have only one access door. I understand NEC allows 48" but to conform with NEC's wordings regarding "unobstructed egress"

egress path that allows a worker to travel to the exit from any other area in the room containing the equipment described in NEC 110.26 (C)(2) without having to pass through that equipment's required working space.

, its practical to just double the elbow room required and you will comply with both codes.

 

[steve66]

If you are under the 2020 code, there is also a new paragraph that states:

"Open Equipment doors shall not impede the entry to or egress from the working space."

In my opinion, that's a very vague requirement, and I'm not exactly sure how to interpret it.

Do we have to assume all the doors on all the panels are all open at the same time? Or can we be a little more reasonable, and assume just one panel has the door open at a time, since that's a more frequent service condition.

And exactly what does "impede" mean? Does it mean I just need room to get around the door, like maybe a 24" wide path around the door? Or does it mean my full working space needs to be clear between any open doors?

Any open door is going to somewhat impede entry or egress, unless the egress door is directly in front of the equipment. So it's more a matter of how wide does the egress path need to be left with the door (or doors) open.

If we consider the worst case, a 4.5' wide working space between two rows of equipment that had 3' wide doors could require a 10.5' spacing between equipment (3' + 3' + 4.5') just to insure there is an unobstructed 4.5' in the middle. But I see all kinds of ways to interpret this requirement that leads to a wide variety of different required equipment spacings. If we only need to maintain a 2' egress around the doors, the 10.5' spacing becomes 8'. If we only consider one door open at a time, its either 7.5' spacing (4.5'+ 3') or maybe only 5' (3' door width + 2' egress path).

The only thing we can be sure of is that in any of the above cases we need more clearance in front of the panel than the standard working space.

Sorry if I'm stepping on any toes here., but IMO, the CMP didn't think this one through. They should have been a lot more specific in exactly what they expected.

 

[Sparky2791]

I guess I was talking about another code (IFC). The required elbow room of 30 inches needs to be doubled when you have only one access door. I understand NEC allows 48" but to conform with NEC's wordings regarding "unobstructed egress" , its practical to just double the elbow room required and you will comply with both codes.

(IFC) What code is that? To me that is the International Fire Code. We use that in PA as part of the UCC set of code we must comply with.

 

[Sparky2791]

If you are under the 2020 code, there is also a new paragraph that states:

"Open Equipment doors shall not impede the entry to or egress from the working space."

In my opinion, that's a very vague requirement, and I'm not exactly sure how to interpret it.

Do we have to assume all the doors on all the panels are all open at the same time? Or can we be a little more reasonable, and assume just one panel has the door open at a time, since that's a more frequent service condition.

And exactly what does "impede" mean? Does it mean I just need room to get around the door, like maybe a 24" wide path around the door? Or does it mean my full working space needs to be clear between any open doors?

Any open door is going to somewhat impede entry or egress, unless the egress door is directly in front of the equipment. So it's more a matter of how wide does the egress path need to be left with the door (or doors) open.

If we consider the worst case, a 4.5' wide working space between two rows of equipment that had 3' wide doors could require a 10.5' spacing between equipment (3' + 3' + 4.5') just to insure there is an unobstructed 4.5' in the middle. But I see all kinds of ways to interpret this requirement that leads to a wide variety of different required equipment spacings. If we only need to maintain a 2' egress around the doors, the 10.5' spacing becomes 8'. If we only consider one door open at a time, its either 7.5' spacing (4.5'+ 3') or maybe only 5' (3' door width + 2' egress path).

The only thing we can be sure of is that in any of the above cases we need more clearance in front of the panel than the standard working space.

Sorry if I'm stepping on any toes here., but IMO, the CMP didn't think this one through. They should have been a lot more specific in exactly what they expected.

In PA we are still under the 2014 code but good to know that was added. As to the discussion of 'how wide does the egress path need to be left with the door (or doors) open." The NEC calls for a minimum 2' wide door out of the room so my interpretation would be at least 2', just my opinion.

 

[steve66]

In PA we are still under the 2014 code but good to know that was added. As to the discussion of 'how wide does the egress path need to be left with the door (or doors) open." The NEC calls for a minimum 2' wide door out of the room so my interpretation would be at least 2', just my opinion.

I tend to agree with your interpretation that a 2' wide egress path should be left open.

But I'm still not sure if we just need to consider one equipment door open at a time, or if we should consider they are all open.

 

[Sparky2791]

I tend to agree with your interpretation that a 2' wide egress path should be left open.

But I'm still not sure if we just need to consider one equipment door open at a time, or if we should consider they are all open.

Love the Grey areas we dance around. I am joining the NFPA as a member soon perhaps I'll pose that question to one of their experts for an interpretation. Straight from the horses mouth approach.