I have a Snapit three light circuit tester. I was using it to check the recepticals in an old rental house I am preparing for sale. I was checking the outlets, as several have been replaced with three prong grounded types. As I suspected, very few of the recepticals are actually grounded. My question concerns the light combinations that this tester displays. This tester has a chart which shows five problem and one indicator for correctly wired. The combinations of the three lights shown on the chart are as follows: center light on - open ground, right light on - open neutral, no light on - open hot, left and right lights both on - hot/ground reversed, left and center lights on - hot/neutral reversed, center and right lights on - correctly wired. My problem is that on a couple of the outlets all three of the lights were on, and the tester does not list this as a possiblilty. I brought the tester home with my to try it on a couple of known correctly grounded recepticals and it register properly. Does anyone have any idea what may be the cause of all three indicator lights glowing in some instances?

I found the same thing while troubleshooting some receptacles at my sister's house. A previous electrician had converted a receptacle circuit to 240v to supply power to a window a/c unit. Check your voltage.

Those testers are but aids - and no substitute for either training, or a real meter.

A number of things will lead to confusing readings; among them are multiple faults and broken receptacles.

What you should do when you get multiple readings, or nonsense results, is to kill the power and remove the receptacle from its' box. Then you can start checking things.

Often these problems can be traced to one spot. I find it easier to locate the problem by first checking ALL 4receptacles. Ones that indicate problems get a piece of red tape on the faceplate; when I'm done, it's often possible to see a pattern. For example, they may all be on the same circuit.

Those indicators are just the three combinations. H-N and H-G should be on, G-N should be off. If those indicators are neon, which takes around 60 Volts to ionize, you've got a big problem! I never use those things because the DMM is going to provide the info I need. Why not use the meter first?
Joe

I use a 3-light receptacle tester all the time as part of the final room by room receptacle check out on new finish wiring. They make it a lot faster and easier to check the TR receptacles required for new and remodel work.
Granted they are not a comprehensive tester, but because they are so handy, that I often find myself using them for initial troubleshooting on a service call before getting out my meter and removing a receptacle and then also again to verify my work after replacing a receptacle.

These testers can light all 3 lights (two dimly) if a bad connection exists on the ground or neutral side. Usually that is just a worn receptacle. You end up with 2 lights in series with the hot and one grounded conductor.

I don't post much here but I have to say I recently bought an Ideal 61-165 and I like it big time. I now go through all the tests on almost every outlet I deal with just because I can.

Welcome back there Matt,
Personally, I'd never use one of them plug-in testers.
If they were as good as they said they were, everyone would be using them and we wouldn't need test equipment like meters and the like.

I've had a pair of these for the last 20 years, pretty much you can test anything AC or DC from 120V up to 750V safely.



{Sorry that is a shocker of a pic}

It has an internal solenoid (by pressing the black button)and will draw about 240mA, so there is no getting any "ghost voltages" mucking up your readings.

One other thing about them is, they are made to last, they are sealed against moisture and when the cord between the probes are un-wound, they can be draped over your shoulders (around your neck), so you know where they are.
In umm, hindsight, it does not pay to sit on one of these testers, them probes are very sharp, as I learned once.

always use a meter or a "wiggy". When you are doing electrical work your meter should always be handy

Three light receptacle testers are handy because you can always have one in your pocket but they don't tell you much more than you can figure out with a night light and they can simply lie to you.

Guys,

I have a set of houses to trouble shoot.
Somebody entered each house, and cut one cable.
My task is to trace the circuits, make the splice.
Accessible JB are ok, and the GC will repair the walls.

I have a telephone transmitter/receiver but this project requires something more sensitive (through the walls, depths of 12" maybe).

I have been going through procedures to Trace the Broken Circuits,
and looking into buying a real circuit tracer.

Any suggestions on procedures?
Any suggestions on tracers?

__________________
Glene77is Memphis, TN
Call it what you will . . .
As Long as the Functional Logic is right.

If the cables were actually cut, they've made you job easier.

Even the relatively inexpensive 'data/phone' type tracers (for use on un-powered lines, about $120) will read through walls, etc.The #701K in this link is truly the 'classic' for this use:
http://www.lashen.com/vendors/tempo/toners_probes.asp#pe701k

For more demanding jobs, for live circuits and even some underground work, this tracer (508S) is useful:
http://www.lashen.com/vendors/tempo/cable_locators.asp#pe508s

It's all a matter of being systematic andpatient. First ID -colored masking tape works great - the receptacles that are working. Then apply the toner to the dead receptacles - I use a plug with a pigtail for this.

The tape ought to give you a very good idea as to what circuit and what area of the house has the break. Use the toner to follow the wire from what you think is the first dead receptacle in the series; when the signal stops, you have your break.

It also helps to know the story behind the problem. For example, was the damage done bofore, or after, the walls were closed in? Was it deliberate or accidental? Could it be something as 'simple' as a wire not connected at a wire nut (something I have found a few times)?

Indeed, my very last service call before leaving Reno was this exact situation - and it was a loose wire at a wire nut. My being systematic made me look like a genius when I found the problem in the very first box I took apart.

Is this a hypothetical question or an actual call? If someone cut a cable after the walls were closed up it has to be in an accessible spot.
If this is new construction and the vandal did this at the FEPAC before the rock went up it might be as easy to fish in a new wire around the bad spot than to get in there. You should be able to get some help in the routing from the original EC ... if he is not the one who cut the wire.

Wait, that thread took a very unexpected turn from page 1 to page 2... is my browser playing tricks on me?

I often heard that quality plug-in testers are good tools for DIYers, telling them when to get a pro involved. They are most definitly not real meters. The Benning Duspol with switched load is certainly the Mercedes of testers
I have a cheaper ripoff and really don't want to miss it. DMMs can quite easily give phantom readings too (high impedance test circuit).

No, Texas, you saw correctly. Another poster has hijacked this thread ....

I can't speak for others ... but I decided to let the thread play out, as even the original post was touching on the topic of troubleshooting.

How about posting a link to that Nenning Duspol tester? I don't think there's ever been one of those on this side of the 'pond.'

From the Benning US site:
Duspol Voltage Indicators Detail.

From that referenced site: (emphasis added)

OK, that's a new term for me. Shocking, perhaps, but irritating?

RH,
It's also known as a Ghost voltage, it can lead you down the wrong path when trying to fault-find circuits.
You need a tester that draws a bit of current (>100mA).

They're talking about phantom voltages, the famous ones that give you weird readings of smething like 60 or 79V AC using a DMM on a supposedly dead line but go down to 0 as soon as a load is connected.

The indication listed (all three Lamps on), sounds like it may be an Open Neutral issue, on 1/2 of a Multiwire Circuit; and there is a connected Load bridging the two halves of the Multiwire Circuit. (???)

Maybe the odd report is due to a N-G bond, with some other Circuitry issue involved upstream, downstream (or both) from the Outlet tested???

In any case, suggest to remove the N-G Bond on all Receptacles, then place a GFCI Receptacle at the "First Outlet" of each Receptacle Circuit - with the remaining Outlets fed via the "LOAD" output of the GFCI Receptacle.

A GFCI Receptacle may be used at all locations, if wanted.

Without the GFCI protection, replace all Receptacles on the mentioned Loops with Two-Wire, Non Grounding type Receptacles.

As others have mentioned, back up the Receptacle Tester's test with a test using a Volt Meter.
I prefer to use a "Wiggy" (Low Input Impedance, Solenoid type Volt Meter) for a "Proof" test.

Scott

I appreciate the explanations. As I've mentioned once or twice before, I worked with an electrician who was super safe and super competent, but tended to answer my questions with, "Because I said so."

He was also a strong proponent of the Wiggy.

You can't fool a Wiggy with induced voltage, but be careful, they can play the devil with electronics. A lot of our wiring was done in the 1960's...no EGC and 480 and 120 in the same pipe.

While it's pricy the TASCO does a slick job.

http://www.tasco-usa.com/inspectorIII.htm

http://www.tasco-usa.com/ins2.htm

The nice thing about them is that they test for conditions in the blink of an eye that otherwise take a lot of time and expertise.

TASCO is the actual manufacturer of many of Greenlee's circuit testers, BTW.

How does a night light show reverse polarity? please explain.

You are right. Maybe we should call them "reverse polarity testers". That is really the only difference between them and a night light ... unless there is a bootleg ground off that reverse polarity connected receptacle, then it says "OK".

McClary's: Welcome to ECN. The poster was referring to, in a disrespectful manner, the plug-in receptacle testers ... you know, the ones with three little lights.