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litebrite 08-30-2010 09:58 PM

Help needed. Advice on reading a Receptacle Tester.
I bought 2 of them. When I plug them in to the wall outlet all 3 lights turn on.

It's the basic kind purchased from the local hard ware store. 2 yellow and 1 red.

I have all 3 lights on. Can't find information relating to 3 lights. What can it mean?

Just Bill 08-31-2010 05:58 AM

There should be a legend printed on the side to tell what lights mean.

litebrite 08-31-2010 06:17 AM

The legend did not show 3 lights.

darren 08-31-2010 07:46 AM

It probably means it is time to throw it in the garbage. Get another one and see if you get the same results.

gregzoll 08-31-2010 08:00 AM

What are you trying to accomplish?

McSteve 08-31-2010 09:23 AM

Check the outlet with a volt-meter instead. The "3-eyed liar" doesn't always give the full story. It can only tell deal with one problem at once, and it sounds like this outlet has more than one wiring problem.

Come to think of it, I'm pretty sure I've seen a 3-light tester with all 3 lights lit; It was on an outlet someone installed in place of a former 240V air conditioner outlet. It was still wired for 240. Definitely check with a meter.

Your quick and basic test goes like this: Between hot and neutral, you should have about 120V. The same between hot and ground. Neutral to ground should be 0V.

If you have 0V between hot and ground, but 120V between hot and neutral, you have an open ground.

If you have 120V between hot and ground, but 0V between hot and neutral, you have an open neutral.

If you have 120V between neutral and ground, and 0V between hot and ground, the hot and neutral are reversed.

If you have 240V between hot and neutral, someone has done something horribly wrong.

If the wiring is old and ungrounded, there are some additional tests you can do by measuring between the outlet and an extension cord plugged into a known-good outlet.

litebrite 08-31-2010 05:52 PM

The manufacture told me it represents a bad ground. I rewired everything new wires, ect... Still shows all 3 lights. I attached a copper wire directly to the ground pin of the tester and plugged it in...... ALL 3 LIGHTS!

Somewhat annoyed I called the manufacture back. They said, ok we need to read you a statement. As follows. This device may show 3 lights if your power source is from an: Isolation Transformer or a Delta Wound Secondary Transformer.

It's not coming from the bad ground, it a signal or lack of signal carried on either the neutral or hot wires.

So if you have 3 lights it just means this plug is worthless for your type of power source. You will need another type of tester. There are different types of transformers and most are compatible with these testers but some are not.

gregzoll 08-31-2010 06:52 PM

Again, what are you trying to accomplish? If you want a decent plug in type tester, get

WillT 01-02-2013 02:51 PM

Kind of old thread but will post for searchers looking for the answer. Having lived in a few OLD houses with questionable wiring and also having used the plug in outlet testers I can only say this: Every time I see all three lights illuminated, although it has only been 4 or 5 times, it means that the hot and neutral are reversed. I always confirm this with another test method but every time this has been the case. I swap the wires and it then tests good.

Joeboo25 01-03-2013 07:42 AM

Since this has been bumped...

Are you sure the ground is actually correct? I have one of these things made by Gardener Bender, and my ungrounded outlets are supposed light up the center light only, but it looks like all three are lit. The two on the outside are either reflecting the center bulb, or they are dimly lit. This is on an ungrounded three prong circuit with an upstream GFCI.

WillT 01-05-2013 11:29 AM

All the times I have seen this it was with properly grounded outlets. I am not sure what would light up with a hot/neutral reverse in an ungrounded outlet.

In an interesting aside, I just happened to see this again yesterday on an outlet a new furnace was to plug into. I switched the hot/neutral and all tested fine. When we plugged in the new furnace, the light codes told us the hot/neutral was reversed. After much head scratching, we discovered why. The nice looking, but homemade, cord we had reused from the old furnace was wired backwards. So even though the outlet was correct, the furnace was also giving us good info. Rewired the cord and all was good. Sometimes this stuff gets crazy.

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