emergency generator location? 1

[KJRISE]

I'm torn between NEC 700 and NFPA 110 7.2 on the requirements on located a stand-by emergency generator for used for life safety emergency egress lighting in a supermarket application.
The NFPA leads me to belive that this 45kw generator cannot be in the same room and normal power electrical gear? The NEC doesn't state this. The plans call for the generator and ats to be located in a room that doesn't have the main service entrance gear but does have the rest of the distribution gear.
Can I locate it there or do I have to have it in a seperate fire rated room?

 

[mpparent]

Because a supermarket would not be considered a Level 1 application, I would say that you could install your gen. in the same room as your service entrance gear. This would put your LF&S system in a Level 2 scenario. However, it's always best to check with your local AHJ.

Mike

 

[KJRISE]

The generator powers a lighting panelboard in which it circuits feed emergency egress lighting, so would that make it level 1?

 

[mpparent]

Please read the NFPA 110 section again.

Mike

 

[EEJaime]

Assuming you have a class 2 mercantile occupancy per NFPA 101, (over 3000 SF or on more than one level,etc...), and you are required to have a system per NFPA 110-type 10, (ten second transfer); Class 2, (2 hour backup(I believe only 90 minutes is req'd)); Level 1, ("Failure of system to perform could result in loss of life or serious injury...."), then your AHJ is going to require your equipment to be segregated. We are going through this on a major airport project at LAX where the installation is existing, and since we are increasing capacity, we are having to go back and fix the existing non-compliant equipment locations. Which has become a major headache. I realize your project is not a 500,000sf public assembly type building, but it is easy for your AHJ to justify requiring the most stringent application of NFPA 101 and 110. Unless you can get him to give you approval up front in writing, (which he won't), I think your only option is to design it as a Level 1 facility. Additionally, NEC 700-12, FPN's 1 and 2 make reference to NFPA and provide the AHJ a mechanism to bring these factors to bear on each installation.

For your protection and to insure that the client does not get hit with an unpleasant surprise when the field inspector brings up the subject, I would recommend you meet with your AHJ, see if they have a policy locally, discuss all these code provisions and then decide which approach serves the client best.

Another factor is the fueling, assuming this is a diesel fueled unit, you are going to have a day-tank, pumps, leak detection, etc..., in the room. It really is a cleaner installation to get all of that out of your main electrical room.

Best of luck on your project.

 

[powerwagon75]

Ditto with EEJamie. For what it's worth...the majority of installations of this type I've been involved with are usually nat. gas or propane (although it's not stated here), and gensets this size were usually installed either on the roof (no mezzanine area), or on the mezzanine level, in the refrigeration compressor area. No matter the fuel, you will have some oil-vapor discharge over time, and not having in in the main electrical room will keep it that area cleaner. Oddly enough, putting them in the compressor room invariably leads to the genset being the recipient of getting filthy. Compressors running 24/7, along with the fresh air ventilation, lends itself to quite a dust/oil collecting environment.