I realize the condition was not truly reversed but something caused those cheap tester to read a reverse wiring. Again when the breaker was replaced the issue resolved. I just thought it was interesting esp. the fact that I have seen 4 Cutler Hammer mains go bad and they were all installed back 12-15 years ago. Yesterday someone on another forum reported the same problem- It was a CH. Not the reverse wiring but the breakers not turning off.-- That's 5 now.
I own 3 or 4 of those little testers. I am kind of a gadget freak. I know that they fail, they false and that they may not work at all. I take each reading with a grain of salt. They have their place, and so does tick tracer, an analog VOM, a DVOM and a solenoid tester, which is the bare minimum a residential troubleshooter should have in his voodoo box, and he should know the nuances and limitations of each type of tester.
All residential troubleshooting should start with the verification and use of a known good neutral. I have been in old houses with switched neutrals that would drive less seasoned troubleshooters crazy. In one house you stand in the middle of the foyer, three or four feet from any wall or light, and it would light up tick tracers. Also in that house, you could walk around with a tick tracer in your pocket and it would go off. Those are ghost houses.
The first thing you would do in a ghost house is verify a solid neutral. In the main panel, totally un-load one side and put 500 to 1000 watts across the other. Check to see that both 120 sides are equal or very close. Repeat with the load on the other leg. Once the neutral is verified, take a roll of wire, connect one end to the neutral bar and take the roll with you and use the other end for reference during testing. Of course, if you see an indication of a bad neutral in the main, it's time to address that and that may take a call to the POCO.
In a good ghost house you will get to see the limitations of testers. This house was so bad I got videos of it somewhere. In the foyer, a tick tracer would indicate without being anywhere near anything electrical. On the conductors, a DVOM would indicate the presence of AC voltages anywhere from 20 to 120 while a solenoid tester would show no AC voltage. It turned out that a neutral was bad in the basement, and a couple lights were neutral switched. One was a metal hanging chandelier type light in the foyer. It was acting like an antenna, causing tick tracers to indicate. After I found and fixed the open neutral in the basement, I found about a half dozen hot / neutral reversals and fixed them.
No more ghosts.
As for CH, I have heard some horror stories and had a bad personal experience with their non-main breakers (I had a 15 amp CH breaker hold 115 amps while we were measuring it. It wouldn't trip and the short causing the high current dropped the voltage in the house enough to dim all the lights) so I don't recommend that brand.
