Bootleg grounds

I made a video showing the dangers of bootleg grounds. Feedback appreciated.

(This post has been edited to include the link to a new and improved video.)


I liked the video I was just a little scared you were going to shock yourself at times🙃

I had the same feeling as Martin but a couple of good info videos, none-the-less, Mike. :sunglasses:

I was enlightened. Thanks, Mike. :grinning:

As to the shock hazard and not waring insulated gloves. I concur with Martin and Larry.

May I add. From my experience, most older homes where I run into RBLG, the outlet/receptacle boxes are steel and the wiring first series MND-3 or K&T.
The renovator would be quite the lazy sort, dumb ass, for stripping down the walls to the studs and installing plastic non conductive outlet/receptacle boxes without rewiring.

Thanks for posting Mike.

In the first video after you opened the neutral splice on the left you have only a single conductor (hot leg) connected to the receptacle on the right is that correct? If so how does the EGC become energized?

I was thinking the same thing Robert.

It could be due to the use of a proximity style tester. IMO it would help the accuracy if these types of tests were performed with a volt meter.

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I agree, the capacitively coupled testers come in a whole range of sensitivities and are not reliable for diagnostic purposes.

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Great Job!

Good question; Still waiting for an answer?

When he disconnects the neutral conductor, the voltage sniffer picks up enough electric field bled to the bootleg EGC via the receptacle from the ungrounded conductor. If he touched the neutral wire of the plug cord after disconnecting the neutral, it would, too, light up the sniffer. The video is inaccurate and misleading in its explanation of the 120v on the EGC without any load. As you understand, it is meant to demonstrate that if the neutral is lost upstream of a bootleg ground receptacle, and the metal casing of an appliance is connected to the neutral of the appliance via a bootleg ground, any 120v load applied by the appliance will attempt to complete the circuit via the metal casing of the appliance. Same reason why the 3-wire dryer is no longer allowed.

I’m editing this reply because I got my videos confused. I’ve made several over the last few months. Since this one has been replied to, I will not delete it, but it does not apply to this conversation.

I tried to trace out the circuit in the video. When I disconnect the neutral, here is what happens. The power runs from the hot side of the outlet and up the lamp cord. It then goes through the bulb an back down the neutral side of the cord, and on to the neutral side of the outlet. Since the neutral is open, there is no current flowing so you don’t get the voltage drop through the light bulb - instead the light bulb is just an electrical conductor. As a result, you have 120 volts at the neutral side of the outlet. Since the neutral and the ground (EGC) are tied together (due to the bootleg), you also have 120 volts on the EGC.

I didn’t see any bulb in the first video.

Nor did I, that would have been easy to figure!

You’re right. The lamp was on my hot/ground reverse video.
Simon Rechkin’s explanation is correct. I should redo the video showing a load connected.

Thanks for the clarification now it makes sense. Without the lamp being involved the EGC could not be energized in the first video as depicted.

Robert, let me ask you something. If you took a multimeter set to read AC voltage and you connected one of its leads to the neutral of 50ft 2-prong extension cord plugged into a 120v receptacle that had a cut neutral. You would then take the 2nd lead and connect it to the system’s ground. What would the voltage be about?

It should be 0 volts. Depending on the meter there may be some capacitive coupling which would give you a false reading of some ghost voltage but since the circuit is incomplete the actual voltage is zero. If the meter read some voltage you could try the test again with a solenoid style tester to confirm that there is no voltage present. That is one of the reasons why a proximity style tester may not be the best tool for the job due to a false positive for voltage.