Unclear readings from 3-light electrical receptacle tester

[Stephen Tashiro]

In testing the electrical receptacles in a house with a Sperry brand 3-light electrical tester, most receptacles test good ( red light off, both orange lights on). However, there are two receptacles where the reading is: Red light is faintly on, center orange light is on, the other orange light is faintly on. The tester's instructions don't give any interpretation for red light on, both orange lights on. Any guesses as to what, if anything, is wrong with these two receptacles?

The receptacles in the house are an old design that has no ground terminal on the receptacle. I tried installing a new receptacle in one location It was an end-of-run situation. I connected the ground wire to a jumper wire to the metal box and a jumper wire to the ground terminal on the new receptacle. I got the same reading from the receptacle tester - so maybe there is a problem in the house wiring (?)

[Rod Sheridan]

Hi, sounds like hot/neutral reversed and no ground perhaps.

Do you have a multimeter?

Regards, Rod.

[Myk Rian]

Use an analog meter. Not digital.

[Stephen Tashiro]

Hi, sounds like hot/neutral reversed and no ground perhaps.

Do you have a multimeter?

Regards, Rod.

Yes. - and somewhere I have a analog multipmeter, but I usually use a digital multimeter.

I found this web page interesting, but it deals with a problem that supposedly my receptacle tester won't detect - "boot leg ground" and "reverse boot leg"
http://ecmweb.com/contractor/failures-outlet-testing-exposed

[David L Morse]

You have no ground. Dim lights should be interpreted as an "off" indication. The metal box probably has no metallic connection to the bonding point in your entrance panel. Use a GFCI that is labeled "No Equipment Ground" or similar instead of a normal receptacle.

[Stephen Tashiro]

You have no ground.
That might be the problem. When I installed the new receptacle, I connected the ground wire from the wall to both the metal box and the ground terminal on the new receptacle using the usual "pigtail" configuration. So the ground wire from the wall may not be grounded. Since this is at an end-of-run, perhaps the ground wire from the wall isn't grounded on its other end where it probably goes into a middle-of-run receptacle.



Use a GFCI that is labeled "No Equipment Ground" or similar instead of a normal receptacle.

That's a good idea and I'll resort to it if I have to.

[Stephen Tashiro]

An update. I bought a "no contact" type of tester. It's red light comes on as soon as the tip gets within 1/2" of the face of one of the bad sockets. On a good socket, the red light only comes on when I insert the tip of the tester into slot for the "hot" prong of a plug.