GFCI Installation

[Larry Hood]

I recently inspected an older home that had a 2 wire system.During the rehab the contractor in lieu of providing an all new 3 wire system installed GFCI outlets through out the house.The only reset type outlets were provide in the kitchen and bathroom.None of the resets would trip or the panel breaker with my 3 prong tester.How do I test the GFCI to confirm that they are working? In addition to that can AFCI be installed in the bedrooms on the same system?? Any suggestion would be appreciated.

[Scott Patterson]

I recently inspected an older home that had a 2 wire system.During the rehab the contractor in lieu of providing an all new 3 wire system installed GFCI outlets through out the house.The only reset type outlets were provide in the kitchen and bathroom.None of the resets would trip or the panel breaker with my 3 prong tester.How do I test the GFCI to confirm that they are working? In addition to that can AFCI be installed in the bedrooms on the same system?? Any suggestion would be appreciated.

With an ungrounded system your little 3-light tester will not trip the GFCI. You need to use the test button on the outlet, this is actually the best way to test a GFCI outlet. You trip the test button and then check each outlet to make sure that the power is out to the other outlets on that circuit.

An AFCI can not be installed on a two wire system.

[ken horak]

With an ungrounded system your little 3-light tester will not trip the GFCI. You need to use the test button on the outlet, this is actually the best way to test a GFCI outlet. You trip the test button and then check each outlet to make sure that the power is out to the other outlets on that circuit.

An AFCI can not be installed on a two wire system.


In realility using the test button on the devcie or circuit breaker is the Only accepted /recognized testing method. It does not matter if it's a GFCI outlet on an old 2 wire system or a gfci outlet on a brand new installation.

[John Kogel]

In reality using the test button on the device or circuit breaker is the Only accepted /recognized testing method. Yeah, but ...I occasionally find a GFCI outlet that trips by the test button OK but NOT the 3 light tester. This indicates a wiring problem, does it not, such as line and load crossed up? Or maybe some internal fault. Maybe it's corrosion of the ground pin socket. Anyway, on a 3-wire system, you need to test them both ways every time to be sure.

[H.G. Watson, Sr.]

I believe you mentioned when you tripped using the test buttons, not all the receptacles were OFF - they may not be GFCI protected, OR there could be other GFCI devices elsewhere that are protecting those other outlet locations which are labeled GFCI protected NO equipment ground.

For example, dead front GFCI devices, combination switch and GFCI devices, or of course, other combination GFCI and receptacle devices elsewhere.

If they are grounded style 125V receptacles and are not provided a equipment ground they must be GFCI protected and marked "GFCI protected, NO EQUIPMENT GROUND" or else replaced with non-grounding style receptacles (two-blade type).

Are you sure the 2-wire system is not using something other than a wire for a grounding conductor/bond, such as metallic conduit?

About a year or so ago we had a few discussions on the perils of using a three-light plug-in tester on ungrounded receptacles especially to try to "trip" a GFCI - I know I posted some references and links to some authoritative articles referencing the PERSONAL danger and hazards of doing so as well as a host of erroneous indications you can receive.

You might want to do some searches.