Yes, it refers to NFPA 99, because that is the controlling document for all of the electrical in a health care facility.It refers to NFPA 99-2018 a lot in Art. 517. It also sends you searching Art. 700. I saw mention of Type 1,2, or 3 circuits. It is a bit of a run around.
The note on the plans states that the Life Support branch may be combined with the Life Safety branch. In my opinion, I would treat it as a second critical branch. The life safety branch saves lives by getting people out of the building. The critical branch saves lives by giving the providers power and lighting to keep patients who aren't leaving the building alive during a power outage. Either of those branches must be available within 10 seconds, and cannot be shed.
The wording is in the 1971 NEC, but I still find the definition rather vague. Or something that I'm not familiar with in old hospitals.I would say there is no difference between that life support branch and a critical branch. It may be some terminology that the hospital or engineers used internally to differentiate between certain loads, or it may be a holdover from older NEC requirements that don't exist anymore. If I was doing anything with that distribution system, I would treat it as a second critical branch.
I can't find copies of NFPA99 from the 70sYes, it refers to NFPA 99, because that is the controlling document for all of the electrical in a health care facility.
The rules in 700 only apply to the life safety branch of an essential electrical system, and even there, not all of the Article 700 rules apply. See 517.26
Because NFPA 99 wants it that way...all of the electrical rules for heath care facilities are under the purview of NFPA 99, not NFPA 70. The NEC only provides installation requirements to meet the performance objectives set by NFPA 99.I can't find copies of NFPA99 from the 70s
Why does 700 only apply to the life safety branch when hospitals work on compartmentalization? Makes no sense.
The NEC is NFPA 70.I don’t have an NFPA book to refer to, but wonder if that’s where the wording comes from?
And I suppose NEC is not allowed to quote NFPA.
The first number in the brackets is the NFPA document that the text has been extracted from. In this case it is NFPA 99, Heath Care Facilities Code. The remaining numbers shown in the brackets, is the section where the text is located at in the original document. Note that most of the other NFPA document use a different numbering system for sections as compared to the NEC.Life Safety Branch.
A system of feeders and branch circuits supplying power for lighting, receptacles, and equipment essential for life safety that is automatically connected to alternate power sources by one or more transfer switches during interruption of the normal power source. [99:3.3.93]
If they under preview of NFPA 99, then why do early versions of 99 quote the NEC word for word going on for pages?Because NFPA 99 wants it that way...all of the electrical rules for heath care facilities are under the purview of NFPA 99, not NFPA 70. The NEC only provides installation requirements to meet the performance objectives set by NFPA 99.