Legally required or optional standby generator?

[anbm]

Hospital has (2) generators (they are not in parallel):

Generator #1 feeds Critical ATS and Life-Safety ATS.
Per NEC, Generator #1 is an emergency generator.

Generator #2 feeds the 3rd ATS. This ATS feeds a panel which has air handler unit
(serving patient rooms and other areas) plus other mechanical equipment
(do not serving patient care areas).

Will generator #2 and third ATS be considered legally required (NEC 701) or
optional standby power system (NEC 702)?

Or this generator is still an emergency generator and the ATS is Equipment branch ATS
belong NEC 517? Thank you.

 

[ron]

517.26 associates the life safety branch with 700.

I've always considered the critical branch as 701 loads and the equipment branch, with the option for delayed or manual operation per its definition, as a 702 load. But those are not as clear as 517.26 and the life safety branch and 700.

 

[Strathead]

Hospital has (2) generators (they are not in parallel):

Generator #1 feeds Critical ATS and Life-Safety ATS.
Per NEC, Generator #1 is an emergency generator.

Generator #2 feeds the 3rd ATS. This ATS feeds a panel which has air handler unit
(serving patient rooms and other areas) plus other mechanical equipment
(do not serving patient care areas).

Will generator #2 and third ATS be considered legally required (NEC 701) or
optional standby power system (NEC 702)?

Or this generator is still an emergency generator and the ATS is Equipment branch ATS
belong NEC 517? Thank you.

I would say that depends on whether your state codes require the air handlers in the patient rooms to be operational during a power outage. Here in Florida, they just passed a law requiring air conditioning in patient rooms in the event of a power failure. So that would mean the generator is legally required. Otherwise not.

 

[kwired]

I would say that depends on whether your state codes require the air handlers in the patient rooms to be operational during a power outage. Here in Florida, they just passed a law requiring air conditioning in patient rooms in the event of a power failure. So that would mean the generator is legally required. Otherwise not.

I agree. If there is anything that is required to be operational during a normal power source failure that would make this a legally required standby system.

 

[steve66]

517.26 associates the life safety branch with 700.

I've always considered the critical branch as 701 loads and the equipment branch, with the option for delayed or manual operation per its definition, as a 702 load. But those are not as clear as 517.26 and the life safety branch and 700.

In the 2014 NEC, 517.26 seems to list the "Essential System", and Figure 517.30 shows this includes all three branches - Life safety, critical, and equipment. So it seemed like all three branches had to be per Article 700.

But just to make it confusing, 517.31 defined the "Emergency System" which only included the Life Safety and Critical Branches. So the two paragraphs seemed to be at odds with each other. But it may have been that the definition of "Emergency" in 517.31 was meant to be different than the definition of "Emergency" in Article 700.

At any rate, as Ron mentioned, in the 2017 NEC, only the Life Safety Branch is listed in 517.26. And I believe the term "Emergency System" has been deleted in 517 for 2017, to remove the confusion.

So I think the answer may depend on what code its under.

Med vacuum pumps and compressed air pumps are usually on the equipment branch. I believe they are usually critical, and it seems like they should be treated like a 700 system. But that's just an opinion.