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Sure Test and False Grounds!

Jeff Remas

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OK, so I have become a real geek because I started using a SureTest by Ideal. It does a bunch of things that are beyond the scope of a home inspector but so what, I have an extensive background in electrical.

Just noticed that since I started using it, I am now finding some "False Grounds". Most of them all had something in common which I thought about but "brushed off" anyway. All of the false grounds have one thing in common:........they are always on receptacles that are close to the main panel!! I had a gut feeling that was going on but I just confirmed it tonight as I finished wiring in a "quad" box with receptacle for my remodeling of the living room. After I tied everything together, I got out my trust SureTest and low and behold, FALSE GROUND!!! Guess what? The quad I just put in is directly over the top of the main panel which is in my basement. This is a first floor quad so it is about 5 feet away at best.

Anyone else notice the same thing?

Hopefully someone can shed some light on this one before I contact Ideal and inquire about it.

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I didn't get any instructions either. I didn't even get a plastic box. I did, however, receive an incredibly strong plastic package that required a reciprocating saw, two dwarf helpers, and a strong will to gain access to the contents.

I also noticed that the new wiring in my son's bedroom showed all false grounds, which was attributed to the electrician that did the wiring. After I got off the phone with myself I felt assured that the electrician was competent and the tool was giving erroneous data. It's very nice to know that the electrician was correct and the tool was wrong.

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I purchased two of them last year. Both had instructions and nylon carrying cases with a zipper top and belt loop.

I was lucky I read the instructions.

You may want to think twice before commenting on the voltage drop issue. I only comment on it if the drop is over 10% and/or it varies more than a couple percent between outlets.

Here is my boilerplate. Beware it is very long. I stole most of it and I would give credit to the person that wrote it if I could remember who I got it from.

A voltage drop greater than normal was detected on one or more branch circuits in the electrical system.


When current passes through a wire, a certain amount of voltage is lost. The result is that the voltage at the point of use will be less than that at the power supply. This loss is called voltage drop. The amount of voltage drop in a circuit is dependent on the magnitude of the current, the diameter and length of the wire feeding the circuit as well as the integrity of any connections along the way. (The larger and thicker the wire, the less the voltage drop will be.)

Voltage drop is important for several reasons:

1. Sensitive electronic equipment such as computers, laser printers and audio equipment may lock-up, shut down or otherwise behave erratically. Certain elements may overheat causing early failure.

2. Inductive loads, such as motors and ballasts, can overheat, resulting in shorter equipment life, and higher operating costs.

3. Resistive loads, such as heaters and incandescent lighting, will operate with surprising inefficiency. For instance, at 10% voltage drop, an incandescent light only produces 70% of its normal light.

4. It is wasteful. The lost voltage in the circuit is converted to heat that is dissipated into unconditioned spaces.

5. It may cause incandescent lights to dim or flicker when other loads cycle on. For instance, lights may flicker when the air conditioner or washing machine start up. Though annoying, this is not dangerous and does not violate any code or regulation.


The National Electric Code does not limit voltage drop in branch circuits. There is a fine print note at 210-19(a) FPN 4, that recommends branch circuit conductors be sized to prevent a voltage drop in excess of 3%, or a total drop of 5%, including feeder losses. Fine print notes are for informational purposes only and are not enforceable. However, Section 110-3(b) says that equipment must be installed in accordance with its listing or labeling. Most electrical equipment is designed to operate at no more than 5% and no less than 10% of its voltage rating. Therefore, I consider voltage drop in excess of 10% to be deficient.


When inspecting homes, I use an Ideal Suretest Circuit Analyzer model ST-1D. This tester applies a 15-amp load to the circuit while displaying the corresponding voltage drop. It then extrapolates the voltage drop for a 20-amp load. In my experience, most homes have at least one circuit that exceeds the NEC's 5% recommendation. However, very few homes have circuits that exceed 10% voltage drop.

Two conditions may be causing this voltage drop. If the cable runs to these circuits are overly long, the resistance of the cable alone will cause the drop. In this case, the remedy will require replacing the cable with one containing larger wires. The other possible cause is poor connections along the way. In particular, the stab-back connections on the back of receptacle outlets have high resistance. If a given circuit passes through enough of these connections, the cumulative resistance can cause the voltage drop. In this case, the remedy will require abandoning the stab-back connections in favor of wire nut connections that have a lower resistance.


I recommend that you have your electrician calculate the cable runs to these areas to determine if the cables are adequately sized. If they are not, have the cables replaced with ones that are appropriately sized. If they are now adequately sized, investigate the integrity of the splices at the outlets, improving them as necessary. Strive for a voltage drop of less than 5%

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Got mine last April…no instructions. Ideal didn’t have a file at that time but created one since which I downloaded, cut up, and made my own little manual. http://www.idealindustries.com/pdf/nd3595_2.pdf for those who are google-challenged.

First house I did with it was a 1920’s home with partially updated wiring. I reported a bunch of ungrounded 3-hole outlets and one false ground in the kitchen. Even though I knew about the 15 foot thing from others, I got kind of turned around in the house and didn’t realize I was close to the basement panel. It was sometime later before I started questioning my finding. [:-banghead] Never did hear back from the buyer, and there were enough other problems in the home that required an electrician so that it wasn’t a big deal. Sparky probably just assumed the inspector (me) was an idiot [:-propeller] or maybe, just maybe, it was truly a jumped outlet. [:-graduate]

Anyway…since then I pop the cover plate off any that I get the reading on no matter where I am in the home…just to be sure. I’ve found three so far that clearly had no ground and a jumper from the neutral. Fun to show the client those ones [:-magnify] and they made the expense worthwhile! The rest have turned out to be false readings because of proximity. [:-turtle]

BTW…I’m on my second unit. The first went dead on me mid-inspection after 6 months. I got a new replacement unit no charge but for a couple of weeks I felt a little less professional using a $5 tester. Never did get an explanation of what caused the failure. Anyone else had problems?

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I think that I am the only inspector on any forum using the INSPECTOR II circuit tester. I admit that I bought the thing in the first place because it would look more impressive to a home buyer, but now I love it.

It did come with instructions (Spring 2001) and it did warn about the possibility of false, false ground readings. But in almost three years I have never had one false reading, no matter how close to the panel I test. I do occasionally measure a false ground and for the first several times that happened, I opened the outlet to look. Sure enough, each time there was a jumper from the neutral to the ground.

I do not know why home inspectors do not like this tester, but I think it is great and looks more impressive than the Sure Test.


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I think what he's saying is; for there to be a voltage drop of any significance there has to be resistance in the circuit. Resistance in the circuit would increase current drawn and generate heat in the effort to push through the bad connections or undersized wire. The voltage drop is symptomatic, not causal. You're right that it's the current generating the heat. But the essence of the statement would be true

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The voltage drop is symptomatic, not causal. You're right that it's the current generating the heat. But the essence of the statement would be true

The waste in energy is the excessive current draw, not any heat dissipated into an unconditioned space.

I get it, you guys are messing with me. This is REALLY Norm Crosby .. right?

Boy, you guys had this fish hooked real good. I'm loose now.


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Hi Rolland... the thread drift here wasn't too kosher, I'd be happy to discuss this w/ you, but it seems like you know the answer anyway. Oh heck, I'll answer, we'll get scolded though for thread drift. 1) it's an amazing profit center for operations like mine

2) It allows me to get cars on the rack and sell other stuff

3) It keeps my nice red concrete driveway accented with brown splotches

4) after I take out it of my client's cars I use it to heat my buildings

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Oh, btw, just received my Sure Test yesterday. Going through the book now. Came with a carry case and instruction book.

Purchased it through Tool Experts.

As I was typing I wasn't sure if I bought it from Tool Experts or Professional Equipment. They shipped a catalog with it so off I went to find it. After asking my wife if she had seen it she said that she had put it in the trash (it's her way of saying I don't need anymore tools [:-smirk])

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I've dropped my Sure Test into a whirlpool tub once, dried it off and it has worked good since. I've dropped it a few times also.

The two problems I've had is that I've worn off the writing on the back that tells me which defect the light sequences indicate. Sometimes I have to go get my three light tester to determine what I'm looking at. The ground prong on the extension came loose and I wrote up half the outlets in a home before I realized what was going on. This happened about 6 months after I bought it.

BTW, I bought mine from Inspector Tools.com (by far the cheapest at the time I bought it) It came with a nylon case and instructions.

My inspector has one of the new SureTest models with the AFCI button on it. I do not like this model because he's had several problems with it already. Sometimes the thing will not tell him nothing. We've found it does this most often on receptacles with reverse polarity. I also do not like the recessed plug it has. He can not test 2 prong outlets with the model.


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I've worn off the writing on the back that tells me which defect the light sequences indicate.

I did the same thing. I got out the little book that came with it and copied the page that shows what the lights mean. Then I taped it to the tester (Cover the whole thing with scotch tape) Works great.

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Just a quick aside....

Anyone who wasn't @ the class taught by Michael Leavitt ("3 Bulb Testers & Big Fat Liars") missed something really good. The fact that I was a raw little guinea pig was one of the best educational experiences I've had in my life. I was humbled in my opinions, something that I value greatly; walking around in the fog of ones own limited experience is dangerous. Michael cleared the fog.

Scott has been pestering me to get a SureTest for a year; he (& Michael) were right, I was wrong.

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Chad: This is a very difficult question, I used to be a mecahnic years past and used to teach auto mechanics and, also owned an auto supply.

You will find this one of the most difficult questions; and I have never found a mechanic that could answer this. I found this out in about 1956 +/- from the Perfect Circle Piston ring manufactures engineer.

In order

#1. Seal

#2. Cool

#3. Lubricate

#4. Clean

Sorry to bore everyone. Rolland Pruner

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  • 2 weeks later...
Originally posted by Bill Burnett

So whats up with three bulb testers and Suretest testers? Are the Suretests worth it or not? Haven't any info on Leavvitt's talk. Bill Burnett

I was the guy Michael used as the guinea pig in his class. I've been mildly curmudgeonly on the SureTest for years; honestly, I didn't want any more fancy tools. I have a whole bag of them.

Long story short; 3 bulb testers are worthless for finding false/bootleg grounds, & many other defects. Michael had a slick little wiring setup whereby he duplicated all manner of goofy wiring that the 3 bulb tester didn't find, but the SureTest did.

Of substantial note; the SureTest will NOT find/analyze multiple defects.

Basically, get a SureTest. The 3 bulb testers are big fat liars.

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  • 3 weeks later...

OK, I just bought the Ideal 61-155 (ST2D) and am playing with it. First, the Ideal people test under a 12 amp load (according to the manual) and extrapolate that to 15 and 20 amps. It probable makes no difference, but that's not the same as in Kurt's boilerplate. (Maybe that was the ST1D? Whatever.)

What is new to me is that it seems that one has to know the wire gauge of the receptacle being tested. That seems clear to me from the instructions: "This allows the user to test a 15 amp rated circuit at full capacity or 80% capacity, and test a 20 amp-rated circuit under a full capacity." Presumably you use the 20 amp mode on the tester when doing a 20 amp circuit. If you use the 20 amp mode while testing on a 15 amp circuit, then it shows a higher drop (it does in my house) than when using the 15 amp mode.

1. Am I understanding this correctly? (The instructions aren't clear re implications.)

2. Am I correct in saying that the wire gauge needs to be known- as distinguished from the breaker size? I assume that it's the wire size that's the significant piece here. Or when Ideal says "15 amp rated" do they mean breaker rating? (I do not assume the breaker size tells me the wire size, by the way.) And if you do have to know the wire gauge at the receptacle, how do you reliably know that without pulling it out if it's back-stabbed?

I think I'm glad I bought it.

-David Lee

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I'm adding this post just to get this topic back to the head of the line. Everybody's ignoring mu question. And I just paid 250 for this thing. I may have to get in the line to call Suretest. Behind the guys who are calling about GFCI trip points.

-David Lee in VA

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