NFPA 99 3-4.2.2.1 generator application

[Scott Watson]

My ? Is regarding generator installation for a type 1 nursing facility... My customer is requesting installation of a generator to supply there whole facility. After performing a power study I found they will need a 450KW unit and a 1200amp service entrance rated ATS and distribution panel for various loads. DADS keep telling me that I need to follow the NFPA 99 3-4.2.2.1 2000 edition which requires separation of life safety, critical and equipment loads over 150kva. That's fine however my customer wants to run the complete facility and not just these loads. What are the requirements for separating these loads and additional ats gear. It does not make sense to install 1 ATS feeding the whole facility then install additional ATS gear for the emergency loads... Please advise or point out the code for NFPA 70, 99 or 110 which would explain this situation. Thank you!

 

[Robert Hutcherson]

Generator Application

Generator Application

I don't have NFPA 99. You could consider installing (1) Panel EMDP sized at the max output of the genset and then install individual CB's, feeders, and ATS units(3pole or 4pole) to seperate the various loads. I would read up on NEC 2008/2011 and verify this installation would comply. I suggest you dicsuss with an EE who has done this type of work. Good luck.

 

[kingpb]

Why 2000 version when 2012 is out?

Your reference of 3-4.2.2.1 does not correspond to anything in the 2012 version. Are you sure this is correct?

 

[roger]

The correct article section for the 2000 NFPA 99 would be 4.4.2.2 The corresponding article section of NFPA 70 would be 517.30

Roger

 

[roger]

Why 2000 version when 2012 is out?

They probably haven't adopted a later version, I think there are some areas still under the 98 (and even earlier) NEC.

Roger

 

[Scott Watson]

You are correct referring to adopting the latest NFPA... still stuck in 2000. What the customer wants is to transfer the whole faculty at once so to have one SE RATED 1200 amp ATS, it doesn't seem logical to place additional ATS's for life safety, critical and equipment branches as described in 3-4.2.2.1... I haven't pulled the 2000 NFPA 99 to confirm chapter and section...

 

[Shoe]

I don't have NFPA 99. You could consider installing (1) Panel EMDP sized at the max output of the genset and then install individual CB's, feeders, and ATS units(3pole or 4pole) to seperate the various loads. I would read up on NEC 2008/2011 and verify this installation would comply. I suggest you dicsuss with an EE who has done this type of work. Good luck.

As Robert said above, this is the correct way to approach. You will need to treat the generator as an alternate "service" going to a main generator panelboard, which then feeds multiple transfer switches. You will also have a normal power service panelboard, which feeds the normal side of these transfer switches, separated per NFPA 99 (NEC 517 / 700) requirements.

 

[necnotevenclose]

An entire system backed up by one ATS? What size generator would you be looking at if you installed (1) ATS vs. breaking up the loads per codes (and local AHJ)?

 

[dkidd]

I haven't pulled the 2000 NFPA 99 to confirm chapter and section...

NEC 700.6 (D) says that the transfer switch serving Article 700 loads shall supply only those loads.

And don't overlook 700.27 selective coordination.

 

[roger]

NEC 700.6 (D) says that the transfer switch serving Article 700 loads shall supply only those loads.

And don't overlook 700.27 selective coordination.

Article 700 is not the applicable article for healthcare facilities, the OP will have to follow Part III of 517, 517.40 through 517.44 in particular.

Roger

 

[dkidd]

Article 700 is not the applicable article for healthcare facilities, the OP will have to follow Part III of 517, 517.40 through 517.44 in particular.

Roger

517.26 Application of Other Articles.
The essential electrical system shall meet the requirements of Article 700, except as amended
by Article 517.

 

[roger]

[/PHP]

517.26 Application of Other Articles.
The essential electrical system shall meet the requirements of Article 700, except as amended
by Article 517.

And the following sections of part III after 517.26 are specific to healthcare facilities which trumps article 700 until there is a void.

Article 700 never uses the term Critical Branch or Life Safety Branch whereas they are both very stringent 517 applications.

Roger

 

[hillbilly1]

I'm not familar with the requirements of a class 1 nursing facility, but if they did not have a generator before, it should be legal to put the whole facility on generator providing the previous emergency systems are maintained (such as battery backups,etc.) but if it did have an exsisting emergency generator previously, then a second switch would probably be required.

 

[necnotevenclose]

NEC 2008 517.41(B) states that on one transfer switch you can combine one or more branches or systems in the facility..with a maximum demand of up to 150kVA.

 

[dkidd]

mistake

 

[necnotevenclose]

mistake?

 

[roger]

NEC 2008 517.41(B) states that on one transfer switch you can combine one or more branches or systems in the facility..with a maximum demand of up to 150kVA.

In the OP's case he is well above 150KVA so the single ATS installation will not work.

Roger

 

[Scott Watson]

We would be utilizing a 1200 amp SE rated ATS with a 450KW 208 Y configuration. So from what I understand is that the system shall be broken up in life safety, critical branch and equipment branch with EMDP from both utility and emergency power. Thats understandable however do not see the reasoning behind this other then having the loads isolated from one another due to possible failures in the system...?

 

[roger]

. So from what I understand is that the system shall be broken up in life safety, critical branch and equipment branch with EMDP from both utility and emergency power. Thats understandable however do not see the reasoning behind this other then having the loads isolated from one another due to possible failures in the system...?

That is the reason. The Emergency System (Critical and Life Safety Branches) are crash and burn, Life Safety is Public Protection and egress, Critical is Patient care issues.

Roger

 

[Scott Watson]

Roger I appreciate you pointing out these articles. As I am only a supplier and service tech for installed systems from residential to commercial/commercial mobile to industrial applications including parallel units up to but not limited to 4.5 megawatts. I have an electrical contractor providing a bid for installation and of course my reasoning for this forum is to point out the actual articles relating to a 100% operating level 1 facility.