Will a GFCI outlet pop when using an external tester if it is connected to a 2 wire system without ground?
The test and reset buttons work when pressing them directly on the outlet, but not with an external tester.
We bought new GFCI outlets and installed those per instructions but they exhibit the same issue.

Will a GFCI outlet pop when using an external tester if it is connected to a 2 wire system without ground?

No.

External testers work by shorting to ground. With a 2 wire system there is no ground to short to.

No.

External testers work by shorting to ground. With a 2 wire system there is not ground to short to.


So, even if it doesn't work with the external tester, if there is an event that would normally cause the outlet to pop, will it pop and cut off power to the outlet?

The only true way to test a GFI is with the built-in tester. Your scenario is a reason.

Now, if only home inspectors would get this message.

A home inspection is a negotiating tool, nothing more.

Thank you for the information.

PS: this has come up because of an inspection!


The only true way to test a GFI is with the built-in tester. Your scenario is a reason.

Now, if only home inspectors would get this message.


So, if the test and reset on the outlet works, then in an emergency situation, the outlet should pop?

Yes, it will work without a ground but not trip with a plug in tester. The GFCI must be marked with the "no service ground" sticker. GCFI's are the only good alternative to use with a 2 wire system.

For a quick basic Test, You can use a Wiggy to Test a GFI, You would have to have an extension cord with a known good ground(Or a wire at ground potential), bring wire or Female end of Extension cord over to the GFI in question. Connect the Wiggy to the Cord or wire Ground and touch other wiggy lead to the Hot of the GFI Recepticle(small slot), it should trip. If Receptacle had a ground, you can plug 1 prong into ground and the other to hot, it should trip. Digital meters don't have enough resistance. A GFI Trips if either the Hot or Neutral is drawing more than the other. Both need equal load or they will trip.