Emergency System Wiring Methods

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charlie b

charlie b

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I am designing a new lab building. It will have its own generator, with separate Emergency (egress lights only) and Optional Standby Systems.

An existing, adjacent lab building has one small lab space that has its own small (12 kW) generator. The generator's output is connected to an ATS, then to a UPS, then to a branch circuit panel, all of which is inside the lab. The generator is located just outside the loading dock between the new lab building and the existing lab building. It is presently treated as Optional Standby. It?s in our way, so it has to be relocated, replaced, or otherwise reconfigured. We are discussing placing this existing load on our new generator.

The lab served by this small generator performs a vital role in the monitoring of seismic activity. For that reason, if we put that load on our new generator, the owner wants it powered by our Emergency ATS. I want to talk the owner out of that, and I would to be able to use some basis other than the fact that the loss of power to this lab would not, by itself, put anyone?s life or safety at risk.

Here is my question: I know that if we supply this load from our Emergency ATS, that will bring into play some rules regarding the feeder from our building to theirs. But will it also require the lab to upgrade its internal wiring, to meet the required wiring methods for emergency systems?
 
IMO they can not choose to add loads to the emergency system, they can only choose to add loads to the optional standby system.
 
The tricky part (that I hadn't mentioned yet) is that this is a state owned university. Article 700 says that "emergency loads" are whatever are declared to be emergency by a code or a governmental agency. I think they could invoke that sentence and declare this lab to be an emergency load. But what I wonder about is whether that would force them to do any rewiring of the lab itself.
 
I am sure you already figured no direct black or white answer for this.

IMHO if someone installs a new emergency supply system and intends it to supply some existing work that existing work would have to meet todays codes or it would put the new work into violation.

I disagree that a university, State owned or not is the AHJ to determine what loads are in fact emergency but you did not ask that anyway. :smile:
 
Wiring methods are not my strong suit. What I am trying to ask is what changes might have to be made in the lab? Separation of emergency wiring from normal wiring? Marking receptacles with some way of designating them as emergency? Others?
 
Charlie: If I were the inspector on this, I would say that only those loads specified in Chapter 27 of the IBC can be on the emergency system. Hopefully you can use that to persaude your owner. In regards to the wiring, I agree with Bob.
 
charlie b said:
Wiring methods are not my strong suit. What I am trying to ask is what changes might have to be made in the lab? Separation of emergency wiring from normal wiring? Marking receptacles with some way of designating them as emergency? Others?
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You may think about relocating the existing emergency generator and refeed the existing main equipment and you are not touching any internal existing wiring within the lab building. Or get clarification from the AHJ if the existing building is to be fed from new standby gen set. The existing system has UPS system so it might not be as critical adding it to the new standby generator.

- JWC
 
charlie b said:
... It is presently treated as Optional Standby.

...if we put that load on our new generator, the owner wants it powered by our Emergency ATS. I want to talk the owner out of that...
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The answer is essentially in your question.

It is more that the owner will have to talk you into it ;)

That is, the load's emergency status cannot simply change on a whim. The owner will have to verify the system is to become an emergency load. It really is that simple. If by some feat he/she/they manage to pull that off, then you'd be obligated... but I wouldn't concern myself with possible wiring method changes until such occurs (unless of course you are getting paid to do it regardless of it becoming a reality :grin:)
 
Thanks for the assistance. I am meeting with the owner's engineering staff this afternoon. If you don't mind, Brother and all, I prefer not to name the client (i.e., the school). It's not really relevant.

Just for the sake of amusement, let me mention that one method they are trying to use to justify placing the load on the Emergency System is by calling it an Article 708 Critical Operations Power System. Based on what work is performed in this lab, that is not a stretch. But reading through 708, I suspect that there would be a vast great deal of changes needed within the lab, if they wish to invoke 708. It is worth noting that the local jurisdiction is still on their own code, and it is based on the 2005 NEC, so 708 is not really a player yet.
 
Here is what they decided to do. The project is in the ?construction documents? phase. In just under two months, we send the plans in for permit. I will show the ?existing lab? as being fed from the Emergency System ATS. If the plan reviewer questions the basis for this design, we will describe the existing lab as being a ?Designated Critical Operations Area,? as defined in article 708. That may bring a host of new requirements to the party. But the new building will take about two years to construct, so there is time to bring the lab into compliance.

The ?first fall-back position? is to either use the owner?s status as an agency of the state government to declare this lab an emergency load as allowed under Article 700, or to petition the AHJ to agree to allow it to be called an emergency load. The ?final fall-back position? is to place this existing lab on the new building?s Optional Standby System, and arrange the load shedding scheme in such a way as to make this load the last to be shed, under conditions of generator overload. One aspect of the design that would have helped in the ?fall-back? mode is that the two ATS devices and their distribution panels are going to be 5 feet apart in the same room. So it would be an easy step to move the source from the Emergency System to the Optional Standby System.

Many thanks for the assistance.
 
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