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Wiring routes out of my garage subpanel through exposed flexible metal conduit (FMC) to metal boxes for just about everything. Garage is detached, and 1990's era. The pool equipment, pool lights, and receptacle circuits all have a dedicated green wire equipment grounding conductor (EGC). The overhead shop lights and garage door circuits don't have such a conductor.

I'm replacing the garage door opener and wondering if I should pull a dedicated EGC wire to the box/receptacle that serves it power. Am I grandfathered in to some 1990's version of the NEC that allowed FMC to be a EGC if the run is greater than six feet? Or was the electrician who did this wrong?

Incidentally the subpanel is feed through a GFCI breaker at the main panel; does this provide code-compliance in the absence of an EGC, if the receptacles on those circuits are labelled appropriately?

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    The NEC permits lights that are made of an insulating material (ie: plastic) to not have grounds. Exception 1 in Article 410. The real question which you haven't answered is how the garage lights are connected to the panel, are they hardwired in, are they on cords going to outlets? Dec 28 '20 at 8:40
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Whether or not you are "grandfathered" it is really foolish to leave a garage door opener on an ungrounded circuit or weakly grounded circuit. (which is what FMC is - it's a weak ground)

People have been killed by something going wrong with their ungrounded garage door opener, they get a ladder out to climb up and take a look at it, touch the unit or wires in it, get a shock and fall off the ladder. It's not the shock it's the fall that gets 'em.

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You need to pull a ground to any path greater than 6'. The 1987 NEC in 250-91(b)ex.1 allowed FMC with the 6' restriction.

The gfci on the feeder or on a branch circuit doesn't buy any indulgences for improperly installed circuits.

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