Reverse Polarity Bootleg Ground and 3 Light Testers

Here’s a good read on reversed polarity of bootleg grounds and the 3 light testers many of us use:

good information…thanks Linas

Good info, also be aware of the number of grounds in the panel. If the age of the house is 70’s or earlier, most of the circuits are 2 conductor and the outlets are mostly three-prong which test grounded, then you’ve got bootleg grounds(aka pirate or false grounds). Start with the panel so you know what to expect when checking outlets.

As always, Mike provides great information. The SureTest will indicate a false-ground and it will also indicate reversed polarity. However, when both conditions exist, the SureTest gives “priority” to the FG condition, and will not indicate the RP.

Here’s a nice website for this and other residential eletrical issues as well.


Was just about to post that my suretest must be on it’s way out… as I recently found a RP bootleg and it only showed F… I used an AC tick to discern…

ALMOST POSTED… and found this video from Mike S, I guess my suretest is working just fine :smiley:

Also a relevant tip… Equipment Grounds required @ receptacles per 1962 NEC… a few years later was to be a full size EG as well…

IMO, flippers are creating some of the most interesting electrical defects… I mean they really just throw anybody in there with a box of duplex outlets and single pole (only single pole / no 3 way :D) switches…

Reverse polarity bootleg… Imagine going to test one in a garage… with a metal plate. zooowww

Good video Tim. Interesting that the SureTest shows only the FG even when there is RP. This now leaves me wondering what I actually found when I came across (what I thought was) this same condition :smiley:

I edited my previous post to correct the misinformation…

Thanks Linas. One of my weak suites.
Nice to see you laughing in your photo.
All the best.

Thanks Mr. Spargo.

That is a good article, Hey Guys, you should consider signing up for Mike’s (not me) news letter. Theres good stuff in it.

Wouldn’t a hot ground reverse be just as dangerous?

Yep worked on my last inspect.
Thanks again.

Hi Guys…

I’m Mike Sokol, the author of the above article about RPBG outlets (Reverse Polarity Bootleg Grounds). Thanks for posting it here as I think it’s something serious to look out for, especially in pre-70’s homes that have had “quick upgrades”.

FYI: I’ve just published a feature article on this topic in the July issue of EC&M Magazine which hits the streets on July 28th. It goes into much more detail about how RPBG outlets are measured and additional dangers to electrical gear that’s cross-connected between an RPBG outlet and a properly wired outlet. Hint: it ain’t pretty… Here’s a link to the early release online version.

Please contact me with any comments or suggestions.

Mike Sokol

All the best Mike.
Thanks for the invite.

I did a commercial that had bootlegged a bunch of outlets. So glad my Client did not purchase the place.

I’ve been going through rewiring my 1926 house room by room, and found that all the old rooms with grounded outlets had been bootleg grounded during a 1970’s remodel. And about 25% of those bootleg outlets turned to to also be reverse polarity. Of course, the reverse polarity problem is accentuated by knob & tube wiring because K&T wiring is typically black, and it appears that the 1926 electricians would sometimes switch the neutral side for lighting, etc…

There also was a pre-fab addition done on my house sometime in the 80’s, and while installing a new sub-panel recently I found that they ran 4-wire cable and decided to use the red wire for the safety ground. Now, this was a pre-fab house put together at a “factory” so I’ve got to assume that’s how it’s always been wired.

So I think that adding a NCVT Proximity Check (Non Contact Voltage Tester) for a hot-ground check is a great addition to any 3-light or Ground impedance tester such as an Amprobe INSP-3 or Ideal SureTest.

To figure out how this all works, I built a portable demonstration rig which allows me to bias any outlet or sound gear with a potential up to 150-volts or current loop up to 30 amps. B&K Precision was kind enough to donate some AC power supplies which work great for this demo. And I’ve also added a 3-volt/30-amp soldering transformer for ground loop current injection to test sound systems for hum problems. See for my NoShockZone test bench.

Mike Sokol

It’s not our job to get emotionally invested in the clients decision.

I have no preference one way or another on whether they purchase the property, only that they are fully aware of its condition prior to making the decision.

I care for every Client I have done an Inspection for and in some cases have sleepless nights because someone has ignored my advice. In most cases this is just someone that can’t see the immediate danger.
I have seen the emotions you display right here on the open MB and have no doubt in my mind that all you care about is your next inspection.
Also when opening your Website I receive a direct warning from my Virus protection.
Testimonies are needed if you want my advice.

You are quite the tool Kevin. Once you have actually performed enough inspections, you will understand what I’m talking about. If you truly “cared” for your clients, you’d refer them to a competent inspector.

I’m Mike Sokol, the producer of these videos and articles about what I consider to be a very important topic… Reverse Polarity Bootleg Ground outlets. In fact, I’ve dedicated hundreds of hours to this one topic because I think that proper testing for RPBG’s can and will save lives. And as someone hinted earlier in this thread, this info might even save your own life someday.

However, I see that this thread is quickly degenerating into a bunch of name calling and mud slinging. While I"m only a guest here, I have in fact posted and answered questions on hundreds of pro-audio and RV forums, and I rarely see this sort of behavior. I’m asking you all to PLEASE act like gentleman and stay on topic. Is that asking too much?