Weird configuration door x

[hhsting]

Attached sketch I have electrical room in which I have emergency electric room. The electrical room has swbd A is over 1200A with over 6 ft wide. Swbd A has double working space. The emergency room has exit entry door X next to swbd A.


Questions:

1. Does 110..26(c)(2)(b) apply to door x or not? Would diagonal distance from door x to swbd A have to comply oer NEC 2017 Section 110.26(C)(2)(b)? It is 3 feet should it be 3 feet 6 inches?

2. If a person exits from emergency electrical room from door x they have to go thru working space of swbd A. If swbd A has explosion then that person can get trap pillar is on the way and distance from pillar to working space swbd A is 18 inch. Is their anything in NEC 2017 that can prevent that?

 

[hhsting]

Attached sketch I have electrical room in which I have emergency electric room. The electrical room has swbd A is over 1200A with over 6 ft wide. Swbd A has double working space. The emergency room has exit entry door X next to swbd A.


Questions:

1. Does 110..26(c)(2)(b) apply to door x or not? Would diagonal distance from door x to swbd A have to comply oer NEC 2017 Section 110.26(C)(2)(b)? It is 3 feet should it be 3 feet 6 inches?

2. If a person exits from emergency electrical room from door x they have to go thru working space of swbd A. If swbd A has explosion then that person can get trap pillar is on the way and distance from pillar to working space swbd A is 18 inch. Is their anything in NEC 2017 that can prevent that?

Add to above emergency electrical room has equipment 200A to 400A panelboard, ATS, transformers 45kVA to 75kVA

 

[Fred B]

Door X would have to go, cannot have egress door opening inward to the path of egress.

 

[hhsting]

Door X would have to go, cannot have egress door opening inward to the path of egress.

Where is that in NEC 2017? One does need 2 hour separation from normal equipment and emergency equipment this room is needed no?

Sent from my iPhone using Tapatalk

 

[Fred B]

Where is that in NEC 2017?


Sent from my iPhone using Tapatalk

OSHA requirements and requirement in 110.33(A)(3) "Personnel Doors. .....the door(s) shall open in the direction of egress and be equipped with listed panic hardware."

 

[hhsting]

OSHA requirements and requirement in 110.33(A)(3) "Personnel Doors. .....the door(s) shall open in the direction of egress and be equipped with listed panic hardware."

110.33 is for equipment 1000v and higher. All equipment are 480/277V or 208/120V. I dont see that requirement in NEC 2017 for those voltages?

 

[hhsting]

Any thoughts on question #1 and #2 post #1?

 

[Fred B]

110.33 is for equipment 1000v and higher. All equipment are 480/277V or 208/120V. I dont see that requirement in NEC 2017 for those voltages?

Are you claiming there is no "high voltage" equipment including the 1200A SWB-A? The no seperation of room required put all equipment in one room, get rid of door X

1. Does 110..26(c)(2)(b) apply to door x or not? Would diagonal distance from door x to swbd A have to comply oer NEC 2017 Section 110.26(C)(2)(b)? It is 3 feet should it be 3 feet 6 inches?

2. If a person exits from emergency electrical room from door x they have to go thru working space of swbd A. If swbd A has explosion then that person can get trap pillar is on the way and distance from pillar to working space swbd A is 18 inch. Is their anything in NEC 2017 that can prevent that?

#1. Door X is not an egress for the large equipment SWBD-A area. 110.26(C)(2)(b) only applies to that peice of equipment and the exiting from that area, door X doesn't provide an exit. While door X and the equipment room it gives access to technically does not have to be open out based on code if equipment doesn't meet language of 110.26(C)(3) 800A or more, the safety consideration none the less are still valid even at the lower amperages, having the door appearance from the large equipment area to open out from that view is misleading and would appear to be a closer egress from the large equipment area in a panic that would happen under a catastrophic failure situation.

#2 while you are correct that potential hazzard associated with such a design is real, the code referenced doesn't prohibit it. So if flames are shooting out of SWBD-A and you are in the smaller electrical room you'll just have to run through the flames I guess. Then make a claim to OSHA.

Might I suggest you look at this info as well. Sometimes some common sense is used and consideration of why it is done in other application.
(Oh wait, there is no such thing anymore, just get out of the driver's seat in your RV and make some popcorn while you're in cruise control. )

https://www.ecmweb.com/national-electrical-code/qa/article/21160218/stumped-by-the-code-nec-rules-for-access-to-and-egress-from-working-space-of-large-equipment

 

[hhsting]

Are you claiming there is no "high voltage" equipment including the 1200A SWB-A? The no seperation of room required put all equipment in one room, get rid of door X


#1. Door X is not an egress for the large equipment SWBD-A area. 110.26(C)(2)(b) only applies to that peice of equipment and the exiting from that area, door X doesn't provide an exit. While door X and the equipment room it gives access to technically does not have to be open out based on code if equipment doesn't meet language of 110.26(C)(3) 800A or more, the safety consideration none the less are still valid even at the lower amperages, having the door appearance from the large equipment area to open out from that view is misleading and would appear to be a closer egress from the large equipment area in a panic that would happen under a catastrophic failure situation.

#2 while you are correct that potential hazzard associated with such a design is real, the code referenced doesn't prohibit it. So if flames are shooting out of SWBD-A and you are in the smaller electrical room you'll just have to run through the flames I guess. Then make a claim to OSHA.

Might I suggest you look at this info as well. Sometimes some common sense is used and consideration of why it is done in other application.
(Oh wait, there is no such thing anymore, just get out of the driver's seat in your RV and make some popcorn while you're in cruise control. )

https://www.ecmweb.com/national-electrical-code/qa/article/21160218/stumped-by-the-code-nec-rules-for-access-to-and-egress-from-working-space-of-large-equipment

Yes all are either 208/120V or 480/277V. Swbd A is 1600A 277/480V equipment. Separation room is provided by designer not my choice unless there is code reference. Designer separated normal equipment from emergency equipment different room

1. About 110.26(c)(2)(b) is it not about egress from working space? I dont see egress from room. The door X does provide egress from working space of the large equipment swbd A. How can 110.26(c)(2)(b) not apply?

2. What i meant was is there anything in NEC 2017 to prevent such install not just 110.26(c)(2)(b)? U sure there is no code reference to prevent this in NEC 2017? Even if door where to open outward hazard still exist as you would have to go thru working space of swbd A.

 

[hhsting]

Are you claiming there is no "high voltage" equipment including the 1200A SWB-A? The no seperation of room required put all equipment in one room, get rid of door X


#1. Door X is not an egress for the large equipment SWBD-A area. 110.26(C)(2)(b) only applies to that peice of equipment and the exiting from that area, door X doesn't provide an exit. While door X and the equipment room it gives access to technically does not have to be open out based on code if equipment doesn't meet language of 110.26(C)(3) 800A or more, the safety consideration none the less are still valid even at the lower amperages, having the door appearance from the large equipment area to open out from that view is misleading and would appear to be a closer egress from the large equipment area in a panic that would happen under a catastrophic failure situation.

#2 while you are correct that potential hazzard associated with such a design is real, the code referenced doesn't prohibit it. So if flames are shooting out of SWBD-A and you are in the smaller electrical room you'll just have to run through the flames I guess. Then make a claim to OSHA.

Might I suggest you look at this info as well. Sometimes some common sense is used and consideration of why it is done in other application.
(Oh wait, there is no such thing anymore, just get out of the driver's seat in your RV and make some popcorn while you're in cruise control. )

https://www.ecmweb.com/national-electrical-code/qa/article/21160218/stumped-by-the-code-nec-rules-for-access-to-and-egress-from-working-space-of-large-equipment

By the way in addition to previous post this is high rise building


Sent from my iPhone using Tapatalk

 

[Fred B]

Yes all are either 208/120V or 480/277V. Swbd A is 1600A 277/480V equipment. Separation room is provided by designer not my choice unless there is code reference. Designer separated normal equipment from emergency equipment different room

1. About 110.26(c)(2)(b) is it not about egress from working space? I dont see egress from room. The door X does provide egress from working space of the large equipment swbd A. How can 110.26(c)(2)(b) not apply?

2. What i meant was is there anything in NEC 2017 to prevent such install not just 110.26(c)(2)(b)? U sure there is no code reference to prevent this in NEC 2017? Even if door where to open outward hazard still exist as you would have to go thru working space of swbd A.

Might Found your requirement..
OSHA 1926.416(b)(1) "Barriers or other means of guarding shall be provided to ensure that working space for electrical equipment will not be used as a passageway during periods when energized parts of electrical equipment are exposed."
During a catastrophic equipment failure, the energized parts are or may be exposed.
Simplest way to ensure that the working space is not used as a passageway is not have the doorway and egress path through the working space as the only means of exit.

 

[hhsting]

Might Found your requirement..
OSHA 1926.416(b)(1) "Barriers or other means of guarding shall be provided to ensure that working space for electrical equipment will not be used as a passageway during periods when energized parts of electrical equipment are exposed."
During a catastrophic equipment failure, the energized parts are or may be exposed.
Simplest way to ensure that the working space is not used as a passageway is not have the doorway and egress path through the working space as the only means of exit.

All this is in high rise building so not sure if in high rise separate room for normal equipment and separate room for emergency equipment is required or not?

We dont enforce osha only NEC 2017. So then nothing in NEC 2017 about working space used as passage?

Also did you my reason 110.26(c)(2)(b) can be used for door x? I still dont get why it wouldn’t apply to door x. Door x is egress from working space of swbd A. No? Its not exit from room but thats not what 110.26(c)(2)(b) says??

 

[Tulsa Electrician]

Does door X have an exit light over it?

 

[hhsting]

Does door X have an exit light over it?

110.26(c) whole is Not about egress from room its about egress from working space. It doesn’t matter if it had exit light or not

 

[Tulsa Electrician]

I will take a stab at it. applies to Door X and the so call EM room
I'm on 2104 so only that will relate to my answer. Yes I know your asking for 2017.
I went to 110.26 (C) 1-3
Start with (3: personnel doors) you have not stated if the equipment in that room falls into that "800 amp or more" a key word there is egress, then the building code, local AHJ and OSHA regulations would apply to meet the intent of egress.
Now for (2), does not meet the 1200 amp or more or does it? Again no equipment list for equipment in that area (so called EM room).
I would say (1: Minimum Required) applies. "give access and egress". So egress rules would apply to door X. Since you have equipment 600v or less in there so called EM room than Door X must be ruled as an egress.

Now for if that door can be removed. That would be an AHJ and building code question. I will say swinging in does go against the 2014 NEC and does not meet the rule for egress and an egress door must in this case swing out and away based on building code. All the electrical code says is that it is means of egress.

Copied text from 2017:
(C) Entrance to and Egress from Working Space.
(1) Minimum Required. At least one entrance of sufficient
area shall be provided to give access to and egress from working
space about electrical equipment.
(2) Large Equipment. For equipment rated 1200 amperes or
more and over 1.8 m (6 ft) wide that contains overcurrent devices,
switching devices, or control devices, there shall be one
entrance to and egress from the required working space not
less than 610 mm (24 in.) wide and 2.0 m (61∕2 ft) high at each
end of the working space.
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.
(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)(1) for equipment operating at that voltage and in
that condition.
(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.

Now for the door, in this case Door X. If the door is required than 110.33(A) (3) applies per 2014 NEC.
key word there " shall open in in direction of egress"

Copied text from 2017 NEC:
(3) Personnel Doors. Where 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.

Now if the door was removed if allowed. 110.33 (A) would apply since there is no door. No equipment list provided for that area so A-(1) may or may not apply. Here is where 110.26 and 110.33 differ in way of Large Equipemnt. 110.33(A) (1) may or may not apply. If you read 110.33(A) (1) (a) Unobstructed Exit.

Copied text from 2107 NEC:
110.33 Entrance to Enclosures and Access to Working Space.
(A) Entrance. At least one entrance to enclosures for electrical
installations as described in 110.31 not less than 610 mm
(24 in.) wide and 2.0 m (61∕2 ft) high shall be provided to give
access to the working space about electrical equipment.
(1) Large Equipment. On switchgear and control panels
exceeding 1.8 m (6 ft) in width, there shall be one entrance at
each end of the equipment. A single entrance to the required
working space shall be permitted where either of the conditions
in 110.33(A)(1)(a) or (A)(1)(b) is met.
(a) Unobstructed Exit. Where the location permits a
continuous and unobstructed way of exit 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 110.34(A), a single entrance
shall be permitted. It shall be located so that the distance from
the equipment to the nearest edge of the entrance is not less
than the minimum clear distance specified in Table 110.34(A)
for equipment operating at that voltage and in that condition.
(2) Guarding. Where bare energized parts at any voltage or
insulated energized parts above 1000 volts, nominal, are located
adjacent to such entrance, they shall be suitably guarded.
(3) Personnel Doors. Where 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.

Maybe re-draw with equipment numbers in the, so called EM Room as to provide a better answer.

 

[Tulsa Electrician]

For room try 110.27 (A) (1)

 

[hhsting]

I will take a stab at it. applies to Door X and the so call EM room
I'm on 2104 so only that will relate to my answer. Yes I know your asking for 2017.
I went to 110.26 (C) 1-3
Start with (3: personnel doors) you have not stated if the equipment in that room falls into that "800 amp or more" a key word there is egress, then the building code, local AHJ and OSHA regulations would apply to meet the intent of egress.
Now for (2), does not meet the 1200 amp or more or does it? Again no equipment list for equipment in that area (so called EM room).
I would say (1: Minimum Required) applies. "give access and egress". So egress rules would apply to door X. Since you have equipment 600v or less in there so called EM room than Door X must be ruled as an egress.

Now for if that door can be removed. That would be an AHJ and building code question. I will say swinging in does go against the 2014 NEC and does not meet the rule for egress and an egress door must in this case swing out and away based on building code. All the electrical code says is that it is means of egress.

Copied text from 2017:
(C) Entrance to and Egress from Working Space.
(1) Minimum Required. At least one entrance of sufficient
area shall be provided to give access to and egress from working
space about electrical equipment.
(2) Large Equipment. For equipment rated 1200 amperes or
more and over 1.8 m (6 ft) wide that contains overcurrent devices,
switching devices, or control devices, there shall be one
entrance to and egress from the required working space not
less than 610 mm (24 in.) wide and 2.0 m (61∕2 ft) high at each
end of the working space.
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.
(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)(1) for equipment operating at that voltage and in
that condition.
(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.

Now for the door, in this case Door X. If the door is required than 110.33(A) (3) applies per 2014 NEC.
key word there " shall open in in direction of egress"

Copied text from 2017 NEC:
(3) Personnel Doors. Where 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.

Now if the door was removed if allowed. 110.33 (A) would apply since there is no door. No equipment list provided for that area so A-(1) may or may not apply. Here is where 110.26 and 110.33 differ in way of Large Equipemnt. 110.33(A) (1) may or may not apply. If you read 110.33(A) (1) (a) Unobstructed Exit.

Copied text from 2107 NEC:
110.33 Entrance to Enclosures and Access to Working Space.
(A) Entrance. At least one entrance to enclosures for electrical
installations as described in 110.31 not less than 610 mm
(24 in.) wide and 2.0 m (61∕2 ft) high shall be provided to give
access to the working space about electrical equipment.
(1) Large Equipment. On switchgear and control panels
exceeding 1.8 m (6 ft) in width, there shall be one entrance at
each end of the equipment. A single entrance to the required
working space shall be permitted where either of the conditions
in 110.33(A)(1)(a) or (A)(1)(b) is met.
(a) Unobstructed Exit. Where the location permits a
continuous and unobstructed way of exit 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 110.34(A), a single entrance
shall be permitted. It shall be located so that the distance from
the equipment to the nearest edge of the entrance is not less
than the minimum clear distance specified in Table 110.34(A)
for equipment operating at that voltage and in that condition.
(2) Guarding. Where bare energized parts at any voltage or
insulated energized parts above 1000 volts, nominal, are located
adjacent to such entrance, they shall be suitably guarded.
(3) Personnel Doors. Where 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.

Maybe re-draw with equipment numbers in the, so called EM Room as to provide a better answer.

You are not following what I am saying. I am not questioning 110.26(C)(1). My question is 110.26(c)(2) applies to door X. 110.26(c)(3) their is 800A equipment or larger and its in electrical room normal.

Here is list of equipment:

Emergency room has 200A to 400A panelboards 277/480V, 208/120V has transformers 45kva to 75kva and has ATS 200A to 400A

Normal Electrical has switchboard A 1600A swbd A 277/480V and two other 1600A to 2000A 278/480V switchboards not shown in sketch post #1.


110.26(c) has Nothing to do with exit signs or exit from room. Its about egress entrance From and To Working Space. In order to move in and out of door X you have to have egress and entrance from swbd A working space. Swbd A is large equipment 1600A 277/480V three phase. Also When you go into door X and out of it you are going in and out of working space of swbd A and so 110.26(c)(2) applies. I have no idea why it would not apply? Also by same toke 110.26(c)(3) applies the side of door X that has 1600A swbd A no?

 

[Tulsa Electrician]

IBC 10-1 – electrical room requirements 1006.2.2 Egress based on use. The numbers, types, and locations of exits or access to exits shall be provided in the uses described in Sections 1006.2.2.1 through 1006.2.2.6. 1006.2.2.1 Boiler, incinerator and furnace rooms. Two exit access doorways are required in boiler, incinerator and furnace rooms where the area is over 500 square feet (46 m2 ) and any fuelfired equipment exceeds 400,000 British thermal units (Btu) (422 000 KJ) input capacity. Where two exit access doorways are required, one is permitted to be a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the length of the maximum overall diagonal dimension of the room. 1006.2.2.2 Refrigeration machinery rooms. Machinery rooms larger than 1,000 square feet (93 m2 ) shall have not less than two exits or exit access doorways. Where two exit access doorways are required, one such doorway is permitted to be served by a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the maximum horizontal dimension of the room. All portions of machinery rooms shall be within 150 feet (45 720 mm) of an exit or exit access doorway. An increase in exit access travel distance is permitted in accordance with Section 1017.1. Exit and exit access doorways shall swing in the direction of egress travel, regardless of the occupant load served. Exit and exit access doorways shall be tight fitting and self-closing. 1006.2.2.3 Refrigerated rooms or spaces. Rooms or spaces having a floor area larger than 1,000 square feet (93 m2 ), containing a refrigerant evaporator and maintained at a temperature below 68°F (20°C), shall have access to not less than two exits or exit access doorways. Exit access travel distance shall be determined as specified in Section 1017.1, but all portions of a refrigerated room or space shall be within 150 feet (45 720 mm) of an exit or exit access doorway where such rooms are not protected by an approved automatic sprinkler system. Egress is allowed through adjoining refrigerated rooms or spaces. Exception: Where using refrigerants in quantities limited to the amounts based on the volume set forth in the International Mechanical Code. 1006.2.2.4 Electrical rooms. Electrical rooms shall be provided with exit or exit access doorways in accordance with Section 110.26 of NFPA 70 for electrical equipment rated 1000V or less, and Section 110.33 of NFPA 70 for electrical equipment rated over 1000V.

The word Egress in NEC, the rest is by other.
on the matter of the exit light. if it had one than I would say by other has determined it was means of egress.

I would recommend you go to the local AHJ for a determination on Door X.

 

[hhsting]

IBC 10-1 – electrical room requirements 1006.2.2 Egress based on use. The numbers, types, and locations of exits or access to exits shall be provided in the uses described in Sections 1006.2.2.1 through 1006.2.2.6. 1006.2.2.1 Boiler, incinerator and furnace rooms. Two exit access doorways are required in boiler, incinerator and furnace rooms where the area is over 500 square feet (46 m2 ) and any fuelfired equipment exceeds 400,000 British thermal units (Btu) (422 000 KJ) input capacity. Where two exit access doorways are required, one is permitted to be a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the length of the maximum overall diagonal dimension of the room. 1006.2.2.2 Refrigeration machinery rooms. Machinery rooms larger than 1,000 square feet (93 m2 ) shall have not less than two exits or exit access doorways. Where two exit access doorways are required, one such doorway is permitted to be served by a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the maximum horizontal dimension of the room. All portions of machinery rooms shall be within 150 feet (45 720 mm) of an exit or exit access doorway. An increase in exit access travel distance is permitted in accordance with Section 1017.1. Exit and exit access doorways shall swing in the direction of egress travel, regardless of the occupant load served. Exit and exit access doorways shall be tight fitting and self-closing. 1006.2.2.3 Refrigerated rooms or spaces. Rooms or spaces having a floor area larger than 1,000 square feet (93 m2 ), containing a refrigerant evaporator and maintained at a temperature below 68°F (20°C), shall have access to not less than two exits or exit access doorways. Exit access travel distance shall be determined as specified in Section 1017.1, but all portions of a refrigerated room or space shall be within 150 feet (45 720 mm) of an exit or exit access doorway where such rooms are not protected by an approved automatic sprinkler system. Egress is allowed through adjoining refrigerated rooms or spaces. Exception: Where using refrigerants in quantities limited to the amounts based on the volume set forth in the International Mechanical Code. 1006.2.2.4 Electrical rooms. Electrical rooms shall be provided with exit or exit access doorways in accordance with Section 110.26 of NFPA 70 for electrical equipment rated 1000V or less, and Section 110.33 of NFPA 70 for electrical equipment rated over 1000V.

The word Egress in NEC, the rest is by other.
on the matter of the exit light. if it had one than I would say by other has determined it was means of egress.

I would recommend you go to the local AHJ for a determination on Door X.

Again your not following what I am saying. See my previous post

 

[Tulsa Electrician]

"You are not following what I am saying. I am not questioning 110.26(C)(1)(3). My question is 110.26(c)(2) applies to door X.

Here is list of equipment:

Emergency room has 200A to 400A panelboards 277/480V, 208/120V has transformers 45kva to 75kva and has ATS 200A to 400A

Electrical has switchboard A 1600A swbd A 277/480V and two other 1600A to 2000A 278/480V switchboards not shown in sketch post #1."


(2) Large Equipment. For equipment rated 1200 amperes or
more and over 1.8 m (6 ft) wide that contains overcurrent devices,
switching devices, or control devices, there shall be one
entrance to and egress from the required working space not
less than 610 mm (24 in.) wide and 2.0 m (61∕2 ft) high at each
end of the working space.
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.
(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)(1) for equipment

Table 110.26(A)(1) Working Spaces
Nominal
Voltage to
Ground
Minimum Clear Distance
Condition 1 Condition 2 Condition 3
0–150 900 mm
(3 ft)
900 mm (3 ft) 900 mm (3 ft)
151–600 900 mm
(3 ft)
1.0 m (3 ft 6 in.) 1.2 m (4 ft)
601–1000 900 mm
(3 ft)
1.2 m (4 ft) 1.5 m (5 ft)
Note: Where the conditions are as follows:
Condition 1 — Exposed live parts on one side of the working space and
no live or grounded parts on the other side of the working space, or
exposed live parts on both sides of the working space that are
effectively guarded by insulating materials.
Condition 2 — Exposed live parts on one side of the working space and
grounded parts on the other side of the working space. Concrete,
brick, or tile walls shall be considered as grounded.
Condition 3 — Exposed live parts on both sides of the working space.