480' sq ft undergroud electric vault

[Mr. Inspector]

2009 codes.

A 30' X 16' room is being built undergroud. Not pre-fab. Roof is at grade. ceiling is 7' high inside. Only has a man hole on roof to get inside. I'm looking for in the building code and the PA-UCC where this building is excempt for egress and ventilation. Can't find anything. The NEC says it's ok with just the manhole in 2008 NEC 110.75 and no ventilation.

 

[jdfruit]

Part of a building or site electric system?

Any switch gear or transformers?

 

[mark handler]

Depends on the code you are under

49 CFR Ch. I (10–1–10 Edition) § 192.179

http://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol3/pdf/CFR-2010-title49-vol3-sec192-183.pdf

United States Government Publishing Office

(a) When the internal volume exceeds 200 cubic feet:

(1) The vault or pit must be ventilated with two ducts, each having at least the ventilating effect of a pipe 4 inches in diameter;

(2) The ventilation must be enough to minimize the formation of combustible atmosphere in the vault or pit; and...

 

[Mr. Inspector]

Enforcing the 2009 IBC and 2008 NEC. There are switch gear and ransformers in this underground room. The electrician says it's just a vault. When does it go from a vault to a building?

 

[Mr. Inspector]

Mark - I think 49 CFR is for plumbing.

 

[jdfruit]

Check article 450 (transformers) for ventilation & part III for vaults, ventilation and readily accessible required. Special stuff if over 35K volts. 215-10 NEC may be applicable. 240-13 NEC may be applicable. 110-26 (a bunch of stuff for under 600volts) may be applicable. 110-30 (another bunch of stuff for 600volts and higher) may be applicable. These NEC sections address ventilation, ready access to equipment, and requirements for doors with panic hardware.

 

[Mr. Inspector]

Over 600V. Looks like we can use section 110.31 (b) (2) In places Accessible to qualified persons only. This only requires comliance with sections 110.34, 110.36, and 490.24. Nothing about doors here.

Please coment.

 

[north star]

( & ) = ( & )

Rick18701,

See also Article 110.70 [ Manholes and Other Electrical Enclosures Intended for

Personnel Entry, All Voltages ] & 110.76 [ Access to vaults & Tunnels ] `14 NEC.





( & ) = ( & )

 

[Paul Sweet]

Check NEC 110.26© (under 600V) and 110.33 (over 600V) for required exits for large switchgear.

I don't know what OSHA considers to be a "confined space", but ventilation might be needed to avoid having to follow OSHA work rules. NEC 110.13 requires free airflow for air-cooled equipment.

Is the manhole large enough to replace the equipment?

 

[Mr. Inspector]

480' sq ft undergroud electric vault

Don't know if the manhole is large enough. Did not get sizes of equipment.

Why doesn't this need to comply with the IBC for egress?

 

[north star]

~ : ~ : ~ : ~

" ...The electrician says it's just a vault. When does it go from a vault to a building?"

To what Occupancy Group is the vault assigned ?~ : ~ : ~ : ~

 

[JBI]

north star, I would presume 'U' occupancy...

 

[north star]

~ : ~ : ~ : ~

Big John,

I would "presume so" as well, but I wanted to see if **Rick18071** had

officially designated the structure in to a category, ...as a starting point

from which egress and other requirements could be clarified.

FWIW, ...Article 110.70 [ `14 NEC ], the Exception would allow for

plans to be designed and submitted for review by the AHJ..........Also,

Article 450.42 provides some "minimum type construction requirements"

for Walls, Roofs, & Floors" of vaults.

Thoughts...



~ : ~ : ~ : ~

 

[Mr. Inspector]

"U" Went to look today. All of the electrical equipment is mounted on the roof. The vault is only used for conduits and wiring.