[morediy7]

I just upgraded seven older 2-prong receptacles with 3-prong, and installing a GFCI receptacle at the first outlet on the circuit. I am using a Sperry GFCI plug-in outlet tester on each of the new receptacles and it indicates that each one is wired correctly (2 adjacent amber lights), and no abnomalities are indicated. The GFCI test button on the tester also works on the GFCI outlet.

I am wondering, however, if a plug-in tester has any actual utility in this application. Since the original wiring has not been upgraded and therefore there is no separate ground (as normally would be found if using14-2 Romex) is there any real meaning when both amber lights on the tester light up? Or any other lights for that matter.

The button on the tester to test the GFCI function on the GFCI receptacle is helpful, but is any other information on the tester meaningful?

Just wondering out loud. Other opinions on this will be helpful. Tks.

 

[Datawise]

If your plug-in tester trips the GFCI receptacle, then I would be checking for "bootleg" grounds. Your tester should still show "open ground" on each new receptacle unless there is in fact a ground (bond) connected to the box.

In the early days of "grounded wire" many electricians connected the grounds to the exterior of the box because the devices did not have a connection for it.

If you box is truly not grounded, and you are getting "normal" indication something is off.

Cheers
John

 

[morediy7]

Tks. The house was built in 1960 and the original receptacle boxes are metal, with bare copper ground running to each. So I guess technically they are grounded, which I presume is why the tester does not indicate open ground.

Basically, as I've done with a couple of other dated circuits in the house, I am just upgrading the outlets to 3-prong, installing a GFCI/AFI receptacle at the beginning of each circuit. All the upgraded receptacles are functioning properly.

For some reason the thought entered my brain, after upgrading this particular circuit yesterday, whether a plug in tester is actually a meaningful indicator of identifying anything wrong after all the new receptacles have been installed.

 

[rjniles]

You have metal boxes that are grounded. Maybe not properly.

I doubt you have a bootleg ground as that would trip the GFCI immediately.

 

[morediy7]

Never thought about a bootleg ground, so I guess a plug-in tester would still be useful in my type of application. Appreciate your responses. Good to see you are still on the forum.

 

[CodeMatters]

With some exceptions based on location, it's generally acceptable by code
to replace two prong outlets with three when they grounded, as these seem
to be.
Also....I'll think about this a little more...but my first thought is that a bootleg
gnd would not trip an upstream GFI under normal use or when a GFI tester
button is pushed....current's all returning on the neutral so no imbalance...

 

[rjniles]

With some exceptions based on location, it's generally acceptable by code
to replace two prong outlets with three when they grounded, as these seem
to be.
Also....I'll think about this a little more...but my first thought is that a bootleg
gnd would not trip an upstream GFI under normal use or when a GFI tester
button is pushed....current's all returning on the neutral so no imbalance...

His grounded metal boxes may because the wiring method may be old BX cable without a bonding wire. No longer a compliant ground.

Sent from my Moto E (4) Plus using Tapatalk

 

[CodeMatters]

Tks. The house was built in 1960 and the original receptacle boxes are metal, with bare copper ground running to each. So I guess technically they are grounded, which I presume is why the tester does not indicate open ground.

If done correctly, this would be acceptable here.
Don't think the op gave his location, so, who knows......

 

[seharper]

I am wondering, however, if a plug-in tester has any actual utility in this application. Since the original wiring has not been upgraded and therefore there is no separate ground (as normally would be found if using14-2 Romex) is there any real meaning when both amber lights on the tester light up? Or any other lights for that matter.

There's a neon-light tester that has 2 test leads and (obviously) a neon light. You connect the test leads to 2 wires, and it tells you if there is 60-300V between them. A 3-light tester is simply doing 3 neon-light tests at the same time. With some risk of interaction/interference (part of the reason the legend is so very useless, e.g. "hot-ground reverse" when the real problem is lost neutral due to interference).

The center yellow is hot-neutral. The end yellow is hot-ground. The red is neutral-ground.

Also....I'll think about this a little more...but my first thought is that a bootleg
gnd would not trip an upstream GFI under normal use or when a GFI tester
button is pushed....current's all returning on the neutral so no imbalance...

Correct.

IF GROUND IS NOT PRESENT:
1 light displays.
TEST button should not trip GFCI.

IF GROUND IS BOOTLEGGED:
2 lights display.
TEST button should not trip remote GFCI ...
... but will trip this local GFCI if ground is bootlegged off LINE.

IF GROUND IS PRESENT AND CORRECT:
2 lights display.
TEST button will trip GFCI.