Given old two-prong (ungrounded) wiring where a GFCI is installed nearest the panel and other two-prong outlets are attached to the load side of that GFCI, how does one confirm that all the outlets are properly protected?
As far as I understand things, a GFCI tester must leak some current to earth to confirm that it triggers a fault. With the earth pin unconnected that test can't be done with a conventional three-prong tester.
Is there a more sophisticated test? Or is there simply no such thing as downstream protection in ungrounded circuits? Must every outlet have its own GFCI?
Best Answer
Testing the initial GFCI receptacle should be sufficient. No need to test the load side receptacles since they are protected by the GFCI. If the GFCI works, and the 2 prong receptacles are connected to the load side of the GFCI, then they are protected.
If however, you wish to pursue it, you would need a separate conductor run to a good ground. Insert the tester into a 3 prong to 2 prong adapter and attach the ground to the ground prong tab (or wire) of the adapter. Then plug in to each of the old 2 prong receptacles to test.
Good luck!