Essential Electrical System in hospitals

[mshields]

Do all loads that could be placed on the generator for a hospital necessarily fall into one of the three categories defined by 517 for the EES. i.e. I realize that the Life Safety loads are very very specific, the Critical loads a little specific but still pretty clearly delineated. But is it fair to say that all other loads may be placed on the Equipment branch?

Thanks,

Mike

 

[skeshesh]

I'm not stating this as a fact because now I'm unsure but I believe that you're limited to what's listed under 517.34, and reason is some of the language used in the section, i.e. 517(B)(8): "Other selected equipment shall be permitted to be served by the equipment system. [99: 4.4.2.2.3.5(9)]". This statement refers to loads that "shall be permitted to be served by the equipment system" as "selected equipment" and refers to the NFPA healthcare standard for further detail on such equipment. As a matter of interest what exactly are you planning to connect to the equipment branch?

 

[steve66]

i agree with skeshesh. The appendix to 99 states :

A.4.4.2.2.3.5(9)

Consideration should be given to selected equipment in kitchens, laundries,​

and radiology rooms and to selected central refrigeration.

It is desirable that, where heavy interruption currents can be anticipated, the transfer load be reduced by the use of multiple transfer devices. Elevator feeders, for instance, might be less hazardous to electrical continuity if they are fed through an individual transfer device.​

I would also add that the NEC 517.33(A)(9) gives a hospital a lot of freedom to dictate what goes on the critical branch. (For standard 20A receptacles and small motors and loads.)​

And, no not all loads on the generator necessarly fall into one of the three branches. A hospital could easily have a separate transfer switch that serves "optional" loads from the generator.​

 

[mshields]

thanks for the input

thanks for the input

I'm not actually lookinig at a specific project so I can't answer your question about what it is I'm looking to puton the Equipment branch. I might also add that I would as a matter of practice always put elevators on their own ATS. But what I really wanted to clarify just for my own edification was when do Article 700, 701 and 702 apply versus Article 517. Clearly, or at least I think it's clear, Life Safety and Critical branch are what you have in lieu of an Article 700 Emergency ATS. And if that's true does everything else even if via multiple ATS's constitute Equipment Branches.

Or

Is it proper to have an Equipment ATS (or maybe several by various category) but then in addition to that have a Legally Required Standby ATS and perhaps too an Optional Standby ATS. Or would those latter two categories be misnomers in a hospital.

Am I thinking too much?

Thanks,

Mike

 

[skeshesh]

I'm not actually lookinig at a specific project so I can't answer your question about what it is I'm looking to puton the Equipment branch. I might also add that I would as a matter of practice always put elevators on their own ATS. But what I really wanted to clarify just for my own edification was when do Article 700, 701 and 702 apply versus Article 517. Clearly, or at least I think it's clear, Life Safety and Critical branch are what you have in lieu of an Article 700 Emergency ATS. And if that's true does everything else even if via multiple ATS's constitute Equipment Branches.

Or

Is it proper to have an Equipment ATS (or maybe several by various category) but then in addition to that have a Legally Required Standby ATS and perhaps too an Optional Standby ATS. Or would those latter two categories be misnomers in a hospital.

Am I thinking too much?

Thanks,

Mike

Mike, I've been told at times I'm thinking too much or that it's not good, but I'm not convinced! Not thinking enough is often the problem IMHO.

In any case, I've been thinking about this but didn't have time to dig into to it a bit in the past day or two. I looked through the articles and my basic understanding is that Article 517 Life Safety branch and Critical branch loads are under systems defined as "emergency systems" under article 700. Article 701 is very close, but is "intended to automatically supply pwoer to selected loads (other than those classed as emergency systems)..." (701.2), which seems to me would indicate the equipment branch. When you size a genset to serve all three branches, you're still giving priority to LSB and CB loads since the ESB will be on a delayed transfer. Article 701 would also apply to legally required emergency circuits that are indicated as such by codes, regulations, what-have-you other than the NEC.

Please let me know what you think as I'm interested in this topic and hope some of the many knowledgeable regulars will chime in as well.

 

[petersonra]

I have spent more time than I care to think about in hospitals the last 5 weeks.

I am kind of assuming the red outlets are the emergency circuits.

I saw all kinds of things like DVD players, TVs, and computers plugged into them.

In one room every outlet in the room was red, although some of the cover plates were white, which I found odd.