Life Support Branch

mbrooke

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Electricity
The NEC is NFPA 70.

There are lots of places where the NEC uses text that has been extracted from other NFPA documents.
When that is done, a reference to the other document is shown in [...] after the extracted text. There are a number of cases of this in Article 517. Here is one example.

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.

Where extracted text is used from another document in the NEC, the NEC technical committee is not permitted to make any technical changes in the text and the purview of the text remains with the original technical committee for the other document. A proposal to change extracted text shown in the NEC cannot be made to the NEC technical committee and must be made to the technical committee that has purview. So if someone wanted to change the definition of Life Safety Branch in the NEC, they would not submit a PI to NFPA 70, the NEC, they would have to submit the PI to NFPA 99, the Health Care Facilities Code.
There are times where the extracted text in one document is out of sync with that in the original document as a result of differing code cycles.

I guess the reason we are so befuddled about the definition of "life safety" is that the 1971 NEC and 1971 TCR PDF graphic says that the Life Support Branch can be combined with the Life Safety Branch:

1613845694030.png


However, in the same 1971 TCR (and NEC) it says that the Life Support Branch may be combined with the Critical Branch if the AHJ approves:



1613845553434.png


The original 1971 ROP PDF lists Life Safety Branch however:

1613846426115.png

The Question is, why the back and forth? What was the debate about? It looks like originally the CMPs were on board with likening the branch to Life Safety but then changed their mind at the last minute.

Further, there appears to be debate about what this branch may feed. They talk about "power centers" "safe patient power centers" "isolated power systems" only, to "power systems" in a list of locations.


1613846893155.png

As I understand it the critical branch does not receive the same level of fire protection as the life safety branch which makes me think Life Support is of higher priority than a critical branch. At least originally. And why did latter version of the code ditch the concept of Life Support, in a hospital?
 

mbrooke

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Location
United States
Occupation
Electricity

mbrooke

Batteries Not Included
Location
United States
Occupation
Electricity
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.
Call me dumb, but it looks like the CMPs in NFPA 70 are wagging the dog here...

Which I would be ok if they could've taken some input from NFPA 101...
 

don_resqcapt19

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Illinois
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retired electrician
Call me dumb, but it looks like the CMPs in NFPA 70 are wagging the dog here...

Which I would be ok if they could've taken some input from NFPA 101...
If we are still talking about Article 517 installations, I don't know what 101 has to do with it. The purview for Health Care Facilities electrical systems rests totally with NFPA 99.
 

mbrooke

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Electricity
I have no idea, but 99 has control, not 101 or 70, if you are talking about health care facilities.

Well... I'm willing to debate that...

101 leads me to NFPA 70-

1614381333259.png

NFPA 99 also points to article 700. 700 confirms it in the fine print:

1614381645339.png

710.10 (D)...

However, the critical branch in article 517 seems to be excluded?
 

don_resqcapt19

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Illinois
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retired electrician
If I'm correct NFPA 99 was first published in 1987... so I'm still inclined to believe NFPA 70 set much of the electrical rules seen today in 99.
It appears that the first edition of 99 was in 1987, but much of the information existed in other NFPA documents prior to that.
From the 1983 Report on Proposals (ROP)
The Health Care Facilities Correlating Committee (HCFCC) proposes for adoption NFPA 99, Health Care Facilities Code,
constituting a combining and complete revision of all the documents under its jurisdiction into one document.
Note that an 83 ROP indicates that there should have been an 84 edition, but it may not have been accepted in the ROC or at the NFPA meeting, delaying it until 87.

Even if it was under the purview of the NEC at one time, the design and performance of a Health Care Facilities occupancy is currently under the purview of 99.

It appears that as far as a health care electrical installation goes, that 99 is written as a performance code, and 70 it written as a prescriptive code telling you how to make an installation that will meet the performance requirements found in 99.
 

don_resqcapt19

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Illinois
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retired electrician
....
Question is, during a fire, do we evacuate a hospital or shelter in place
...
Certainly I think the NFPA is ok with remaining in the hospital during a fire? No?
Have you ever tried to evacuate a hospital under emergency conditions??....I have, and it is impossible to accomplish fast enough to protect patients from a fire. The only answer is fire protection systems and construction and shelter in place.
 

mbrooke

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Location
United States
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Electricity
Have you ever tried to evacuate a hospital under emergency conditions??....I have, and it is impossible to accomplish fast enough to protect patients from a fire. The only answer is fire protection systems and construction and shelter in place.

100% agree, however, the NFPA 99 and the NEC say otherwise.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
517.26, its amendments, and in particular that the critical branch is excluded.
No where does the NEC address evacuation of any building....it only tells you how to wire egress lighting and other safety equipment that is required by other codes.
 

mbrooke

Batteries Not Included
Location
United States
Occupation
Electricity
No where does the NEC address evacuation of any building....it only tells you how to wire egress lighting and other safety equipment that is required by other codes.
Right- on the basis that the building will be evacuated. Or people will move to another location within a large building. As such there must be continuity of electrical service to fire alarm panel, egress lights, and command intercom. Ditto for the fire pump, despite being a separate branch.

What life safety would there be if all the exits signs and stairwells went dark? I can't find my way out...
 
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