what to do with the insulated green wire

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chateau mike

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A debate has sprung up at our shop whether the insulated green grounding conductor in hospital grade mc cable is bonded to the box before connecting to the device? It is 50/50 in code and manufacturing installation reccomendations about what to actually do. I believe it should not be attached to the box because of the unique properties of the hcf mc already does this job. Please clear this up. Thank you :-?
 
chateau mike said:
A debate has sprung up at our shop whether the insulated green grounding conductor in hospital grade mc cable is bonded to the box before connecting to the device? It is 50/50 in code and manufacturing installation reccomendations about what to actually do. I believe it should not be attached to the box because of the unique properties of the hcf mc already does this job. Please clear this up. Thank you :-?
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box needs grounded. Easy to go to box first
 
In my opinion, first 517.13(A) requires the box to be grounded by the cable armor.

Then 517.13(B) requires that same box to be grounded again by the insulated equipment grounding conductor.

Now some might argue that the receptacle box is not subject to 'personal contact' but that is a hair I would not choose to split. :smile:
 
alfiesauce said:
So if he needed an isolated ground -pull a three wire and use a tagged red as the isolated ground?
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That can be a violation of 250.119.

You can buy Health Care MC IG which would include another conductor that is green with yellow stripes.
 
can you buy NM with that same color coding?
example- using nm in new construction house for an isolated ground in a metal box?
 
My house has some older NM with the grounding wire green insulated (and one size smaller than the other conductors). I know of no NM with both insulated and bare grounds, and I don't know why you'd want it.

NM cable already effectively has an IG since the cable is totally non-metallic. The box on the wall is typically nailed to a non-conductive wood stud. Just where is badness going to come into the ground on an NM wiring system in a wood construction implementation?
 
To have an IG receptacle on an nm circuit with only one ground wire you will have to us a non-metallic box and a non-metallic cover plate.
 
some cents

some cents

The green insulated conductor must be bonded to the device box. The outer bare grounding conductor is as Mr. Belarge stated, a redundant ground. When you cut the HCMC, you are supposed to leave the bare conductor long and bend it over so it wraps from the inside of the cable to outside of the metallic sheath. It basically gets sandwiched between the inside of the HCMC cable connector and the outer sheath of the MC cable. Hope this helps if you didnt know this already.
 
I don't think # 4 or # 5 post answered any part of the OP question clearly,
answer the question, don't state what you think they implied.

Thats not what they asked and that is not the answer.
Since you want to bring in hospital grade material there's 4 wires, a hot, a neutural, and two grounds
one being an isolation and another a bare ground and the Green yellow goes to the device, bare on green nut
 
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cadpoint said:
I don't think # 4 or # 5 post answered any part of the OP question clearly,
answer the question, don't state what you think they implied.

Thats not what they asked and that is not the answer.
Since you want to bring in hospital grade material there's 4 wires, a hot, a neutural, and two grounds
one being an isolation and another a bare ground and the Green yellow goes to the device, bare on green nut
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Now here is a perfect example of a person in a "glass house throwing stones"
or
"the pot calling the kettle black". :D
 
Hospital

Hospital

I have to agree with Cadpoint, in my expierence dedicated ground in the sheathing doesn't go to the box.
 
Aledrell said:
I have to agree with Cadpoint, in my expierence dedicated ground in the sheathing doesn't go to the box.
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If the opening poster was asking about isolated grounds then I would agree.

But the OP is asking about redundant grounding required in patient care areas
 
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