517-2 def. of a health care facilities.it includes a clinic. 517-13(a) lists MC as an acceptable wiring method, as long as it's outer metal sheath is identified as a grounding path. the MC cable has to have an insulated ground in it. It is usually called Hospital grade, and has a green paint on it.
[This message has been edited by trekkie76 (edited 08-26-2004).]
Very unlikely you will get MC with a sheath that is an acceptable grounding conductor, I use MC all the time and have never seen the type of MC that has the right kind of armor for grounding.
What you need is hospital grade AC cable.
The outer armor is a listed grounding conductor along with the added green grounding conductor.
Bob Badger Construction & Maintenance Electrician Massachusetts
Jon look at 250.118 (9) and 250.118 (11). That will explain the difference between AC & MC. Hospital grade Mc I'm told is custom order. Probably explains why I and iwire have not seen it.
Capt al, once again there is no such thing as hospital grade MC. There is MC with a sheath that is recognized as a ground per 250.118, and it is allowed for redundant grounding per 517.13, but that is not a Health Care Facility Cable.
well then, someone should start making Hospital grade MC becuase it is listed as a wiring method in 517-13a. Just because you have never seen it doesn't mean it can't be used or doesn't exist.
As far as MC meeting the requirements of 517-13 (99 NEC reference) some types can meet this requirement and the smooth type is one of these, but this still is not a "Hospital Grade" cable.
Yes, I have seen the smooth type MC, and you have too most likely. Some appliances have it installed from the factory, but as Iwire says it is not common in our field.
And I will say again, Hospital Grade MC does not exist, HCFC is an AC hybrid.