Kwired I need you to clarify something. There's a post that is about mc outer jacket acceptable for a ground. If so then how do you get around using the ground that's in the cable assembly? You surely can't 're identify it can u ? Or just leave it unconnected.?the post is corrugated mc
When it comes to the topic of this thread - if pulling through a box or conduit body with no splices or connections to contained devices - you don't have to bond to the enclosure - but that probably doesn't come up too often with MC cable.
Otherwise with smaller multiconductor MC cable the sheath is not the EGC except for fairly recent design types like MC-AP. Those cable types do not contain an internal EGC unless they are a type designated for use in health care areas where the wiring method must qualify as an EGC as well as contain a "wire" EGC.
I guess the question maybe is can you use the cable primarily designed for health care applications without connecting the contained green conductor?
In general my answer is no, but I don't have a code section to fully back that up either. My reasoning is if you pull a green wire through a raceway that otherwise qualifies as an EGC, you still need to use it and bond it to boxes where necessary. Now one can say pulling that green in a raceway is a choice, but I say selecting a cable with the green is a choice as well.
Other exception would be to use the listed cable sheath as the EGC and the contained green conductor for an isolated ground application.
Those cable types that do list the sheath as a grounding means also have the aluminum bonding strip in intimate contact with the sheath - the idea is to bond each turn of the sheath to ensure less resistance - in the unlikely event that no turns were contacting one another and any current in the sheath had to make every loop the sheath material does - that makes a much longer conductor out of the sheath. The bond conductor is not the EGC, the sheath is not the EGC - but together they are the EGC.