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I recently spent several frustrating hours trying to figure out why an outlet on a new branch circuit would not power a load even though there was proper polarity at the outlet, my non-contact voltage tester showed a live circuit, and my multi-meter showed 110 volts both in the outlet slots and at the side-wire screws. I tested all conductors for continuity, remade all connections, tried four other duplex outlets and three other breakers, and even replaced some of the wiring. Nothing worked. Finally, I hooked up the hot side to another breaker in a different "slot" in the breaker box. That powered the load in the outlet, so I then hooked up the hot side of the circuit to the original breaker and put it in that same slot and it worked. I concluded that something is wrong with the bus bar at the position where the breaker I'd been using was installed. After finishing the job and putting the cover back on the box, I labeled that slot as not working and indicated that the breaker itself may be OK. The box and breakers are Cutler Hammer.

I found no visual evidence of a problem with the bus bar. Is this problem common? Why would my meter have shown 110 volts at the outlet when the outlet wasn't able to power a load? I had thought at first that the outlet was haunted but was happy to find that there was a "real" reason for the problem.

Does anyone have a step-by-step checklist of things to try when troubleshooting a non-working outlet (or any other problem for that matter)? I'm envisioning something that would start with the most likely causes and solutions and work down to the more exotic ones. Such a checklist sure would have saved me time.

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  • I used both a 100 watt trouble light and a floor fan. As I noted, neither would operate when plugged into the outlet, even though the multi-meter showed 110 volts at the outlet. Once I moved the breaker to another slot on the buss bar, the appliances turned on when plugged into the outlet.
    – user13781
    Commented Jul 5, 2013 at 23:15
  • You should have also measured the voltage when there was a load on it.
    – Brad Gilbert
    Commented Jul 7, 2013 at 1:14
  • Mike, you are correct. I moved the breaker from a circuit that does work, with an electric fan plugged into a working outlet, into the problematic slot and the fan did not work.
    – user13781
    Commented Jul 8, 2013 at 14:52
  • Brad, perhaps I should have done such a test. But what would it have proved? I discussed this problem with my step-son who is finishing up an engineering degree at VA Tech and who had four years experience working on USAF planes. He said it was not uncommon for a circuit on a fighter to show the correct voltage but show only a tiny fraction of the correct amperage. He suspects that was my problem. Of course, as I think I already noted, my meter will not measure amperage. Even if I had known that low amps was the issue, how would that have pointed to a bad buss bar slot?
    – user13781
    Commented Jul 8, 2013 at 14:53
  • Hello Do you have 240v across both buss bars ? yes/no missing one leg of 240v ? or using 120 circuit to feed panel and not installing a jumper to other leg. God Bless Big Jim
    – Big Jim
    Commented Nov 11, 2014 at 14:41

1 Answer 1

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Some breaker panels have blank slots at the end, which could mechanically accept a breaker, but their tabs are not live, if they have tabs at all. This is done to lower manufacturing costs and reuse one chassis with different bus bar assemblies.

It could also be a piece of tape, clear insulation, or severe corrosion over that spot on the bus bar. Depending on the resistance, it may let a charge large enough to measure get through, but when an real load is placed on it, the resistance is too high for it to run.

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