Recently in our rental house we replaced the old two conductor outlets with three conductor outlets plus a GFCI outlet at the beginning of the series. Power from the panel is connected to the 'line' side and downstream outlets are connected to the 'load' side of the outlet. Since there is no ground wire in the boxes and the boxes themselves aren't grounded we added a wire connecting the ground screw back to the neutral post. Our testers look good at each outlet and everything appears to work fine with one exception: the GFCI test button on the tester only trips the GFCI at the actual GFCI outlet. At any outlet downstream from the GFCI, the tester doesn't cause the GFCI to trip. My understanding (from this question) is that the initial GFCI outlet should also protect all the downstream outlets. This question also seems to apply but I'm not getting the same results, possibly because of the "ground to neutral" connection. Am I misunderstanding? Or have I done something wrong?
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This is why a licensed electrician is required to work on a rental property. You're more than welcome to electrocute yourself or members of your family by doing your own cowboy electrical work, but you're not allow to kill members of other families.– FreeManCommented Aug 23, 2022 at 17:55
2 Answers
Never never NEVER connect the ground of an outlet to neutral!!! Depending on the situation, you can end up with a dangerous or even lethal voltage on the ground and therefore, on the case of something plugged in.
It is legal and advised to use a GFCI to install 3-prong outlets on an ungrounded circuit. This also applies to standard outlets downstream of a GFCI. The outlets must be labeled "GFCI protected, no ground" (labels should have been provided along with the GFCI).
You should remove all of the "bootleg" grounds.
BTW, the reason the tester didn't trip the GFCI is that it works by connecting line to ground through a resistor to simulate current leaking to ground. However, because the outlet ground is actually connected to neutral, there is no actual leakage.
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1So removing the "bootleg" grounds should allow the tester to trip the GFCI from any outlet on the series? Commented Aug 2, 2016 at 18:26
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4No. The tester still won't trip the GFCI from a downstream outlet. There is no way for it to work without a separate ground. Commented Aug 2, 2016 at 18:41
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1Moreover, the tester will not trip the GFCI once the bootleg ground is removed– KrisCommented Aug 2, 2016 at 22:05
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I wonder if it would be practical for an electrical-equipment company to design a GFCI for the "no equipment ground" scenario, with a weak connection between ground and neutral (e.g. a pair of series-connected 100K resistors) along with a circuitry to trip if the potential across the first of those resistors exceeds 25 volts (representing a current of 0.25mA)? That would ensure that if a ground fault develops in a device, the GFCI would trip immediately even if there wasn't yet any current path from the supply hot that didn't return via the supply neutral.– supercatCommented Jan 1, 2020 at 20:18
If you really want to test those down-stream outlets (vs accepting the fact that they will be protected if wired properly), you can do this:
- Get one of those 2 prong / ungrounded to 3 prong / grounded adapters. It should have a small metal piece sticking out that would normally be attached to the middle screw of the outlet.
- Connect a long piece of wire to a convenient grounding location such as a water pipe or ground wire.
- Connect the other end of the grounded wire to the metal tab of your 2 -> 3 prong adapter.
- Plug in your tester and press the test button.
This should cause the GFCI to trip, since the tester now has a path to simulate a ground fault.
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1There's no guarantee that plumbing is grounded. Most plumbing is plastic these days and PVC or PEX really aren't all that good at conducting electricity.– FreeManCommented Aug 23, 2022 at 17:56