Emergency vs Legally Required

[augie47]

From an inspectors viewpoint, I have always relied on prints, etc. to identify "emergency systems".
A question arose concerning wring sharing raceways and it appears "Emergency Systems" in 700.9(B) can not share with "non-emergency" systems, but "Legally Required" per 701.10 can.
I find that from reading 700 and 701, I can;t make a fine line distinction between an emergency system and a legally required system. Can someone shed light ?

 

[Joe Villani]

Augie

I have always looked at the building code and equated emergency loads as to be governed by article 700 in the nec.

The building code does not use the term "legally Required" instead used the term standby loads.

In the case of high rise construction, (for example) both emergency power and standby power are required. Thus 700 and 701 loads.

The only real way to find the differences is to look at the building code summary on the approved set of drawings, go into the building code to find the use and occupancy classification and determine the emergency loads and standby loads from there.

That is why I feel electrical plan review is critical. It aids in inspection and greatly diminishes cost impacts to contractors.

As a side note in NYC electrical code admendments eliminates article 701 requirements and requires them 700 loads. Makes things a little easier.

Joe Villani

 

[rbalex]

From an inspectors viewpoint, I have always relied on prints, etc. to identify "emergency systems".
A question arose concerning wring sharing raceways and it appears "Emergency Systems" in 700.9(B) can not share with "non-emergency" systems, but "Legally Required" per 701.10 can.
I find that from reading 700 and 701, I can;t make a fine line distinction between an emergency system and a legally required system. Can someone shed light ?

It's my opinion that "emergency" tends to get used rather liberally by engineers/designers until the realization of the extra cost and inconvenience sets in - kinda like over-classifying a location "just to be safe." Per the NEC these should be clearly identified statutory requirements rather than an AHJ's judgment.

That said, this is one of the times the FPN/INs are very helpful. See the definitions in 700.2 and 701.2. Personally, in absence of a clear statutory requirement, I tend to look at it as, "What happens when the lights go out?" ;i.e., is the threat to life immediate such as means of egress being compromised, operating rooms go dark, critical patient life support systems fail, etc. I consider those "emergency". Where the danger takes a bit longer to develop such as loss of refrigeration, heating, other life support systems, processes that may cause a hazardous location if they fail, etc., I consider them legally "required standby".

Most owner/operators consider any loss of process an "emergency" because of loss of product; hence the common engineer/designer response. Again, after I explain the extra cost the NEC imposes by identifying something as "emergency", most owner/operators back down.

 

[texie]

From an inspectors viewpoint, I have always relied on prints, etc. to identify "emergency systems".
A question arose concerning wring sharing raceways and it appears "Emergency Systems" in 700.9(B) can not share with "non-emergency" systems, but "Legally Required" per 701.10 can.
I find that from reading 700 and 701, I can;t make a fine line distinction between an emergency system and a legally required system. Can someone shed light ?

Required emergency lighting and exit signs are just that. That's why they are in Article 700, Part IV. Legally required systems are for other hazards that are deemed hazardous by the AHJ if the power is lost. If you are using a generator for emergency lighting, it is an Art. 700 system and has to be installed as such.

 

[charlie b]

If you are looking to get the right answer on a test question, then it is easy. From a practical perspective, it is less so. The book answer is that a load is "emergency" if, and only if, some authority (be it a code book or a state rule or some other jurisdiction's call) says it is emergency. A load is "legally required standby" if, and only if, some authority says it is legally required standby. In the buildings I have helped design, other than hospitals and in Seattle, the only emergency loads are the egress lights and the exit signs. The Seattle exception is that I have had to put at least one elevator on emergency for some buildings. The only legally required standby loads I have encountered are the smoke control fans and associated components in a high rise. Everything else has been optional standby, no matter how important the lost revenue might be to the owner, if the utility power is lost.

 

[eprice]

I agree with what has been said. I like the way Charlie explained it the best. Typically I think the building code is the best place to start as most requirements are going to come from that. If the IBC is the adopted building code, chapter 27 is a good place to start. That chapter lists things that are required to have emergency power and things that are required to have standby power (ie. legally required standby, because the building code is requiring it)