When replacing an existing outlet with a GFCI the rules are no ground then no ground downstream. when there is a full size ground then connect all grounds. What is the accepted practice when a reduced size 16ga bare ground is connected. Do you open the ground connection, continue the ground downstream; or connect the reduced ground on all devices
LK: In my opinion, a reduced size (wire guage) ground conductor is better than "no ground". The older NM cable had 16 gauge ground, and most of that cable was/is #14, for the hot and neutral conductors, and should be on a 15 amp OCP.
As an AHJ ion NJ, I would accept the undersized ground. For any arguments, I would fall back to "good old common sense", but as there is no NEC article for that, I would use the NJ "Rehab" Code out of the UCC (5:23 et al)
I find reduced grounds under cable clamps, twisted under sheet metal screws and pushed through holes in the box. None of these connections are good grounding practices. When installing a GFCI I find it best to check all down stream ground connections. It looks like everyone agrees reduced ground better then none at all. LK
Then of course a reduced ground will show a ground with your average tester, but may increase the resistance enough in the event of a fault to not trip the OCPD. In which case it would be better to mark the GFCI as "no equipment ground" so no one is deceived about the actual grounding ability of the circuit.
Steve: Good point this is why some type of marking should note the missing link. I have a problem finding a label NO EQUIPMENT GROUND the GFCI Mfg. should put them in the box. They have about 4 info sheets in there now.
In this situation, why is the existing (reduced) equipment grounding conductor better than none? The whole circuit is protected by a GFCI, which will trip faster than the breaker will, in the event of a ground fault. That is it's function. IMOI, I would think the reduced egc is equal to no egc. Don't use it.
If you are talking about a non-gfci protected circuit, then, yes the reduced egc is preferred to none. _________________ Rick Miell