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How do I test an ungrounded receptacle for GFCI protection on a 2-wire circuit?

Friday, June 25, 2021

If the receptacle is a GFCI-type with TEST and RESET buttons, just push the TEST button. It does not require a ground connection to verify that the GFCI protection is functional.

    But a single GFCI receptacle will protect all the other receptacles downstream also (but not the ones upstream between the GFCI and panel). One simple way to test the other receptacles on the circuit is to trip the GFCI receptacle with the test button, then check to make sure that all the other receptacles on the circuit have lost power. Hopefully they are all marked with a “GFCI PROTECTED OUTLET” sticker if still two-slot, or both “GFCI-PROTECTED OUTLET” and “NO EQUIPMENT GROUND” if converted to three-slot.

    Another way to verify GFCI-protection at the other receptacles is more complicated. Inset a “grounding plug adapter” like the one shown below, also called a “cheater plug,” into the receptacle, and connect the metal stub (at arrow) with a wire to a known ground. Although the metal stub is designed to be secured under the screw for the receptacle faceplate to make a ground connection, that almost never has an actual ground connection. Running a wire to a known ground is necessary. Then plug any GFCI-tester into it to check for GFCI protection.

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Here’s links to a collection of our other blog posts about AFCI and GFCI RECEPTACLES AND CIRCUIT BREAKERS:

What is the difference between what trips a GFCI (ground fault) receptacle and a circuit breaker?

Are Ground Fault Circuit Interrupters (GFCIs) really necessary and worth the trouble? 

What is the difference between GFCI and AFCI circuit breakers? 

Where are GFCI receptacle outlets required?

When did arc fault circuit interrupter (AFCI) breakers first become required?

How do I identify a combination AFCI (CAFCI) circuit breaker? 

What electrical hazards does a Ground Fault Circuit Interrupter (GFCI) NOT protect against?  

When were GFCI receptacle outlets first required?

What happens when you press the "TEST" button on a circuit breaker in an electric panel?

What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?  

My bathroom electric receptacle/outlet is dead and there are no tripped breakers in the electric panel. What's wrong?  

My GFCI reset button is hard to push and won't reset. What's wrong?

Why do some breakers in my electric panel have a "TEST" button on them?

    Visit our AFCI AND GFCI page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

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