ECN Forum
Posted By: ggardiner 517.13 - 11/05/01 05:04 PM
If in Article 517.13 it states
Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas

The section was completely revised to read as follows:

Wiring in patient care areas must comply with (A) and (B) below:
(A) Wiring Methods. All branch circuits serving patient care areas must be installed in a metal raceway or cable that is listed in 250.118 as an acceptable grounding return path, such as EMT and/or Type AC cable. Figure 517-1

(B) Insulated Equipment Grounding Conductor. In areas used for patient care, the grounding terminals of all receptacles and all noncurrent-carrying conductive surfaces of fixed electric equipment operating at over 100V, likely to become energized and subject to personal contact, must be grounded by an insulated copper equipment grounding conductor. The grounding conductor must be sized in accordance with Table 250.122 and it must be installed in a wiring method as identified in (A) above. Figure 517-2

Author’s Comment: AC cable is listed as a suitable ground fault path because it contains an internal bonding strip of aluminum in direct contact with the metal armored [250.118(9)]. The outer metal sheath of interlocked MC cable is not listed as a suitable ground fault path in 250.118(11), therefore it cannot be used to supply branch circuits in patient care areas of health care facilities. Figure 517-3
Intent: This section was completely revised to clarify that only metal raceways or armored cables listed as a ground return path containing an insulated copper equipment grounding conductor can be used for branch-circuit wiring supplying equipment, luminaires, and receptacles in patient care areas of health care facilities.

My question is can I use a 12/2 MC cable with an Isolated Ground according to this it doesn't seem so but the extra ground should do the same job as done in the AC cable. Any opions or comments.
Posted By: resqcapt19 Re: 517.13 - 11/05/01 06:22 PM
The intent of the code is to have an external metallic surface that is listed for equipment grounding. Unless you have the type of MC cable that has an outer metallic covering listed for use as an equipment grounding conductor, you can't use MC.
Posted By: ggardiner Re: 517.13 - 11/08/01 08:37 PM
I may be missing something here but 12/2 mc has a ground then if you place an isolated ground in there too is that not complying with the intent of the code? In other words I stuck here with this one and need some help
Posted By: resqcapt19 Re: 517.13 - 11/08/01 09:36 PM
No, The external surface of the cable must be a listed equipment grounding conductor. They want the external surface to be in contact with the building components to provide multiple parallel grounding paths.
Don(resqcapt19)
Posted By: ggardiner Re: 517.13 - 11/08/01 10:52 PM
Thanks for the help I may have some real fun trying to find a replacement for some applications. But asking was worth the try
Posted By: Nick Re: 517.13 - 11/08/01 11:01 PM
Ggardiner, AFC makes a hospital grade type AC cable with a full size equipment grounding conductor. It should serve your purpose just fine.
Posted By: resqcapt19 Re: 517.13 - 11/09/01 03:29 AM
Yes, AC cable is fine as long as it has an internal equipment grounding conductor. The outer metallic covering of AC cable is listed as an equipment grounding conductor, while the outer coverning of MC cable is not. By the way any AC cable with an internal EGC is suitable. There is no requirement to use the green hospital grade AC cable.
Don(resqcapt19)
Posted By: electure Re: 517.13 - 11/09/01 12:57 PM
www.afcweb.com/afccable.html
Their SoCA distribution center is right down the street from me.



[This message has been edited by electure (edited 11-09-2001).]
Posted By: ggardiner Re: 517.13 - 11/09/01 02:22 PM
Thanks but unfortunatly in one county in California they won't allow AC cable used in Health Care. whichs puts me back to square one thanks anyway
Posted By: Nick Re: 517.13 - 11/10/01 12:31 AM
The entire county or just a particular city. Which one?
Posted By: ggardiner Re: 517.13 - 11/11/01 01:28 AM
actually I'm not sure one way or the other I was told it was the county but when I tryed to verify it I got nowhere. All I know is we had to change the AC cable as it was they allowed MC cable with an indepenant ground but the new code book puts a stop to that so I have to find something I can use as an alternative.
Posted By: electure Re: 517.13 - 11/11/01 12:50 PM
The wording of this Section has been slightly changed, but the intent is still the same as it was in the '96 NEC. It is exactly as Don stated above.
M/C cable could only be acceptable if the armor was an approved grounding path. I've seen an M/C with a continuous corrugated, not interlocked, armor. Not sure how it was rated or who made it. To my knowledge there's no manufacturer that makes an M/C with an interlocked armor approved as a grounding path.
A/C cable, though is approved.
It sounds like you better break out the EMT bender, as flex isn't acceptable as a grounding path either.(LA used to accept square cut Al flex years ago, but doesn't any longer)

You've got us CA kids wondering to which County you are referring. Please don't keep us guessing.
Posted By: Bill Addiss Re: 517.13 - 11/11/01 04:50 PM
Take a look at the MC/IG Cable on the following page (bottom). It lists it specifically as being acceptable to 250.118
Quote
References & Ratings

  • UL 83, 1479, 1569, 1581 File Reference E80042
  • NEC 230-43, 250-118, 300-22(c), 318, 321, 334, 517*, 518, 520, 530, 645
  • Federal Specification J-C-30B
  • UL rated for Cable Tray and Environmental Air-Handling Space installation; 1, 2 and 3-hour through-penetration Fire Wall rated


* With prior approval of authority having jurisdiction only.

Look at the last type of Cable on this page (MC/IG)
Note also that they have a Technical Support Link and Tele# on the Bottom of that page.

http://www.afcweb.com/mctype.html



[This message has been edited by Bill Addiss (edited 11-11-2001).]
Posted By: David Re: 517.13 - 11/11/01 07:09 PM
A FEW years ago while working in a patient care area, on a hospital addition we used a cable that came with a duel listing MC/AC.
It also came with a hospital grade listing.
It got the MC listing because it had the green insulated conductor it got the AC listing because it had the continuous bonding wire, It got the hospital grade because of the combination of both.

[This message has been edited by David (edited 11-11-2001).]
Posted By: ggardiner Re: 517.13 - 11/12/01 03:20 PM
Electure
The area in California was Sacramento all I know it was a lady inspector down there that told us we couldn't use AC-HCF for an Isolated Ground Receptacle in a Dentists office. It caught use by surprised because it had been allowed every where else up to this happening.
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