teddyu wrote:
Something is wrong with the GFCI receptacle or its wiring. Pressing the test button DOES NOT induce a ground into the system to trip the GFCI. The test button shunts current from the hot side to the neutral through a current limiting resistor. Conclusion: the GFCI is bad, the neutral is open, or the neutral and ground are reversed - in other words the wiring to the GFCI is messed up. JM2¢...
Close but with a few errors. The test DOES connect the hot side through a resistor to ground. The actual operation of a GFI does not depend on a ground, only the test function requires a ground. If the hot and neutral are reversed then the test button will not trip the GFI. The GFI works by detecting a difference of current flow between the hot and neutral. Here is a link to more info that goes with the picture below.
http://gfciplug.com/index.php/how-does-gfci-work
