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	Subject - Is your Hospital electrically fit? LIVEWIRE Does anybody want to talk hospital or clinic electrical design? Put your question in as a new topic. cs409 sure, kick it off. cooker4160 I am all for talking about hospitals. Most of my life is spent in one any more or so it seems. LIVEWIRE I would be happy to respond to any questions pertaining to hospital electrical design. Step up to the plate. cooker4160 are all hospital fresh air intakes located nest to the diesel exhuast for the generators? LIVEWIRE It seems most prevalent in the "Blue States". Russell120 Have you done any work with NFPA 99? It's the NFPA's "Hospital Book" and has a number of electrical sections confusingly scattered about. With section 4 being the big one. What I am trying to figure out is how this interacts with the various NEC requirements that pertain to Hospitals. I don't think NFPA 99 is "code" in North Carolina, but it is referenced in almost all the specs. LIVEWIRE Russell120, I will be away until Monday PM. Will get back to you then. cooker4160 Russell120 you are correct about NFPA 99 and chapter 4. However you will find informatiom in 110 and also 101 that pertain to the electrical systems in a hospital. What I have learned about hospitals is that they are their own enity. A lot of places deal in big $$$$$$ but hospitals deal in lives. With that aspect in mind I never compromise to save a buck. I don't always get my way but I will always go down kicking and screaming. One of my best arguement enders is "if it were your babies life on the line (subsitute any thing that gets attention) would you do it that way?" LIVEWIRE cooker4160 What branch circuit methods for routing of emergency conductors (in the hospital) are approved in your neck of the woods? cooker4160 Only those listed in 517 We require all emergency conductors to be in a metalic non-flexible raceway. Russell120 Cooker, thank you for the information. I have been a little under the weather of late so I have not been as quick to respond as I should. I will have to look into those NFPA references. My problem with the hopitals is that they pull from so many different NFPA codes and guidelines, that I am afraid I will miss something. One of our projects has an independent agent doing commissioning (what I call the "start up" version of commissioning). He seemed to think I would mind his presence. I actually find it reasuring to have a knowledgeable second set of eyes. Do your hospitals make use of a lot of interstitual space. It seems popular here, but I had not run into it before. It is essentially a "floor between the floors." It is above the accoustic hung ceiling and up to an additional 10+ high. It is really part of the floor below, but there are lots of catwalks and even small mechanical rooms (mezzanines of a sort). Is this a normal hospital design or relatively rare. It seems effective, but obviously more expensive from a first cost point of view. It does allow for a lot of heavy maintenance and a certain amount of construction while the hospital continues to operate. cooker4160 Not at this time. But there is talk of it in a building project forthcoming. Another option that is being expolored is a midlevel mech. floor. Where all of the susytems for the upper floors would come from allowing most ,aintenance to be done out of site out of mind. (so they think) This is from 517.32 (3) Mechanical Protection of the Emergency System. The wiring of the emergency system of a hospital shall be mechanically protected by installation in nonflexible metal raceways, or shall be wired with Type MI cable. Exception No. 1: Flexible power cords of appliances, or other utilization equipment, connected to the emergency system shall not be required to be enclosed in raceways. Exception No. 2: Secondary circuits of transformer-powered communications or signaling systems shall not be required to be enclosed in raceways unless otherwise specified by Chapters 7 or 8. Exception No. 3: Schedule 80 rigid nonmetallic conduit shall be permitted if the branch circuits do not serve patient care areas and it is not prohibited elsewhere in this Code. Exception No. 4: Where encased in not less than 50 mm (2 in.) of concrete, Schedule 40 rigid nonmetallic conduit or electrical nonmetallic tubing shall be permitted if the branch circuits do not serve patient care areas. Exception No. 5: Flexible metal raceways and cable assemblies shall be permitted to be used in listed prefabricated medical headwalls, listed office furnishings, or where necessary for flexible connection to equipment. FPN: See 517.13 for additional grounding requirements in patient care areas. So this is what the NEC has to say. The other codes you referance for instalation always come back to the NEC. For maintenance issues and testing requirements 99 and 110 will be used for life safety 101 and then there all the gas piping codes and everything else you must learn to be in a Health Care envirnoment. Any help I can be just let me know. LIVEWIRE Cooker/Russell I don't think there is an easy answer to NFPA-NEC cross references, only to recognize that they exist. Just for discussion - We believe the electrical inspectors do not/can not enforce electrical issues addressed in NFPA, but not in the NEC. Some of NFPA is recommendation, not requirement. It seems that many items in the NEC started out being only in the NFPA, where they were kicked around and refined, then implemented in NEC. I believe this example holds true, today, for NFPA recommended guidelines for layout of Essential Electrical System equipment, not yet in NEC. On the topic of hospital emergency branch circuitry: As you mentioned, NEC 517 is enforced around here, except as follows: Consulted electrical inspectors are allowing the use of hospital grade MC cable for installing new devices within existing walls. A j-box is installed where the MC cable exits the wall in the ceiling space. The remainder of routing in the ceiling is pipe and wire. These inspectors are not allowing standard flex to be fished into the walls, even with a grounding conductor. The inspectors want the "redundant jacket ground" of the hospital-grade MC cable. Question: When you are working in a hospital where the maximum demand on the electrical system is 150KVA or less, it appears the NEC now removes Life Safety and Critical from the Essential system umbrella (see Figure 517-30 No.2). Can use MC cable for Life Safety and Crital under these conditions? Cooker: Have you found any exceptions to 517.30.C.(3)exception 3 elsewhere in the code? I always thought PVC was toxic under fire conditions, and not permitted within hospitals, except under slab and up to a transition point about 3' or less above slab. Another topic: In the early 80's I was an electrical team member involved in the 2 year design of a new Federal Medical Center. This project was designed using interstitials. The concept was that each room was directly fed from the interstitial above. Therefore, any room could be remodeled without affecting the rooms next to it. Not sure the concept ever had a payback or that it accomplished anything that a good gameplan couldn't accomplish elsewhere. Ever see that program "Fleecing of America?" Each discipline was assigned a given elevation range witin the 10' high interstitial (let's just say electrical was given from the 3' to 6'elevation). This allowed electrical to run N,S,E,and W without conflict, within this elevation range. Vertical transition "guidelines" locations were formed. Inter-discipline coordination was required for variations. Worked out pretty nice on paper!! (guess it was mylar overlay - back then). 6-500's in parallel. Oh yes, it was fun. Hope to hear back on the Q's. LIVEWIRE Sorry, when referring to Figure 517-30 No.2 - I meant to say: "It now appears Life Safety and Critical have been removed from the Emergency System umbrella (150KVA or less). Can we use MC cable for Life Safety and Critical under these conditions"? cooker4160 First off what you are refering to as hospital grade mc cable is actually an AC cable. On the subject of 150kva or less life safety and critical have the same importance and classifactio0n as they do in a larger hospital. The differance is obvious that the whole system is smaller. As far as inspectors allowing the use of AC or Mc cable in areas that are not intended to be that way, all I can say is what other pages of the code do they take out. I understand that in the 2005 code this will be an acceptable wiring method but until we adopt you bet I will be cutting wall board and installing pipe and wire. As far as pvc being toxic and all of that I don't know. I have heard it for years but have never seen it in the book. Code says the following about patient care areas 517.13 Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas. Wiring in patient care areas shall comply with 517.13(A) and (B). (A) Wiring Methods. All branch circuits serving patient care areas shall be provided with a ground path for fault current by installation in a metal raceway system, or a cable armor or sheath assembly. The metal raceway system, or cable armor, or sheath assembly, shall itself qualify as an equipment grounding return path in accordance with 250.118. Type AC, Type MC, Type MI cables shall have an outer metal armor or sheath that is identified as an acceptable grounding return path. As far as the rest of your post if this forum allows you to contact me via email and you are interested I can lead you to some pretty good publications to learn about what it takes to be a health care electrician. LIVEWIRE Got out of the install side of business. Kept cutting the pipes off too short. cooker4160 Livewire IMO the answer to your last question would have to be no if they are in a paitent care area. and if it is life safety or critical they are part of the emergency system so again I would say no. (3) Mechanical Protection of the Emergency System. The wiring of the emergency system of a hospital shall be mechanically protected by installation in nonflexible metal raceways, or shall be wired with Type MI cable.