NEC code question?

[anbm]

I have two questions hope some of you can clear for me:

1. I heard some where in NEC or building code indicates when you have a high rise office building, we have

a. Provide an emeregncy generator

b. Separate egress lighting + fire alarm load on a separate ATS from other load.

Do you what particular section of NEC or building code talk about this rule? And how long (hour) should generator require to serve the emergency load in case of loosing normal utility?


2. I know the TVSS using with switchboard rated at 320kA, 240kA, 180kA, etc. Are these standard number? How do we decide what rate of TVSS should we use?

Thank you!

TX-man

 

[DonPhillips]

1) Section 403 of the 2006 International Building Code.

Don Phillips

http://worthingtonengineering.com

 

[alehman]

And Article 700 of the NEC.

 

[anbm]

alehman,

would you be more specific which article?

 

[anbm]

I mean, which section based on 2005 NEC.
Thanks!

 

[7anoter4]

See: NFPA 101 Life Safety Code chap. 11.8

http://www.nfpa.org/freecodes/free_access_document.asp

NFPA 70[NEC] article 701
NFPA 110 Standard for Emergency and Standby Power System

http://www.generac.com/PublicPDFs/0173220SBY.pdf

But :
NFPA 110 does not address what facilities or loads within a building require an EPSS, nor does it prescribe required classifications for an EPSS. Ultimately, this responsibility lies with the authority having jurisdiction (AHJ) for the site of the construction project, such as the local building inspection or fire marshal's office. Requirements for NFPA 110 compliance may be included in local laws, ordinances or regulations. Local authorities should always be consulted to determine
requirements for specifying NFPA 110 compliance on any project.
Regards

 

[alehman]

NEC Article 700 is for "Emergency systems"
These are things such as emergency lighting, fire pumps, elevators, fire alarm and other life safety related systems.

NEC Article 701 is for "Legally required standby systems"
These are non-life-safety systems that are otherwise required to have backup power. These might be things like HVAC, smoke removal and water supplies.

The terms are defined in the respective articles. Determination of the category for each system is largely up the specific building code and local building authority.

 

[alehman]

NFPA 110 provides design, operation and maintenance requirements for such systems. It may or may not be required in your area. Again, check with the local building authority. As with all codes, be sure you are using the correct edition, as there are significant changes. It is a worthwhile standard, even if not officially required.

 

[rbulsara]

anbm:

What DonPhillips said..you begin there. There are more than one Code that apply, depending upon what your state legislation has adopted (state where the project is located). But they all include NEC, a Buidling Code ( IBC or UBC), a Fire satety code and many others. All those codes may refer to many standards so they end up being requirements as well. On top of that local building officials and big cities have their own requirements, especially for high rise building.

So if you are looking for an aswer on platter, that is unreasonable expectations. It appears that you are new to the consulting world. You need to take time and read some codes for your benefit and direction.

IBC, NEC and NFPA 101 are just a good place to begin. Also look up previous high rise building projects designed by your firm.

NFPA 110 does not tell where a emergency power system (generally a generator system) is required, but it spell out what needs to be incorporated if it is required by other applicable codes.

 

[anbm]

I think you all misunderstood my question maybe because of my English. I am from north Texas and worked in an MEP consulting firm, with healthcare project, there is a requirement from Texas Department of Health requires the generator to have enough gasoline capacity to support emergency load for continuous 24 hours in case of loosing normal utility power. And if you have day tank installed inside the building, it can't contain more than 695 gallons (I think this belongs mechanical code) and it is only applied for health care projects.

For high rise non-healthcare buidling, I heard somewhere in buidling code requires us to provide an emergency generator for emergency load needed (egress lighting, fire alarm, etc) plus other load if required by owner. I couldn't locate this information anywhere, it can be UBC not NEC.

But the generator in this application doesn't need to have big tank to run for 24 hours continuously after loosing normal utility power. And in this case, we have to put egress lighting + fire alarm load on a separate ATS from other (for example: elevator or AC unit if owner wants). Sound likes no codes address this issue. If it does, this can save some bucks to specify generator with smaller belly tank size that can support 8 or 12 hours rather than 24 hours of gasoline. Again, I couldn't find the information about separate ATS anywhere in NEC.

Of course if we use battery ballast for egress lighting, the ballast need to support 90-min in emergency mode as we all knew. If we have generator, the egress lights can be fed from generator through ATS. Thanks!

Tx-Man

 

[davidbeach]

Only 24 hours? That was proven thoroughly inadequate in 1989. It was a mad scramble to keep the hospitals in San Francisco fueled following the earth quake. The standard for health care facilities is now 96 hours of fuel. It means that it takes a much larger tanker to refill the on site fuel tank, but there doesn't have to be a constant shuttle of fuel tankers.

 

[waross]

There is a difference between the main fuel tank and the "day tank" Typically a day tank is refilled automatically from the much larger main tank. The day tank is near the generator to facilitate trouble shooting and maintenance.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rbulsara]

If the state's healthcare department wants 24 hr that becomes one of the many requirements. You also need to ask the owner of the hospital what do they want, meaning how do they want their hospital to survive in case of a power loss.

Also look up NFPA 99. I do not recall any specific code saying requiring a specific runtime for health care, but I have not worked on health care project lately.

Separate ATSs are required by NEC 517 and NFPA 99.

Waross is right about the daytank and main tank. The daytank need not be sized for total fuel requirement. The maintank needs to be.

 

[anbm]

I agree that separate ATS is required per NEC-517 but if the building is non-health care category, they still requires separate ATS, that makes me worry and yes, in Texas they only requires 24 hour for generator backup running time and for ambulance center they requires only 8 hours. Hopefully, the normal utility power is back on within that range.

anbm

 

[davidbeach]

Gee, no hurricanes, no earthquakes, no natural disasters of any kind, must be nice - but highly unrealistic.

 

[cranky108]

North Texas, isen't that tornado alley?