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.
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.
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
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)
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)