Last night, we got a brownout. Everything came back except the master bedroom circuit. I checked the circuit breaker and it wasn't tripped (reset it anyway, for good measure).

After a hot night (window A/C was on the same circuit), I thought I'd see if maybe the A/C was the problem. I unplugged the A/C, and immediately the rest of the circuit came back on. I plugged it back in, and it went off. After a little more playing with the plug, I managed to get it so both the A/C and the room had power.

Any idea what can cause this? I'm nervous about what will happen with the next brownout, and if this is indicative of some more serious problem.

2 Answers 2


I believe what Kris is saying is perhaps you should look at the back of the AC receptacle. Are the wires going to the plug all on the plug? If there are more than two blacks in a box we usually marrett them together with a pig tail that goes to you receptacle screws. Some people go the lazy route and poke each wire into the back of the plug, instead of making a pig tail. Over time things can become loose. I don't know how the brownout could contribute to this but electricity can be finicky in ways!

  • I opened it up, and there were two black wires going into the receptacle, and one was loose. As I couldn't get it to stay in, I ended up buying a new receptacle (one that had screws). My guess is any kind of motion either connected or disconnected it.
    – mlv
    May 31, 2015 at 0:16
  • 2
    Good job! Yes, most electricians do not use the push in tabs on the outlets. It's not wrong, just often a problem. You were right to replace it though for one with screws. May 31, 2015 at 1:57

Sounds like the circuit is daisy-chained. If the AC receptacle is damaged or has bad connections then a daisy-chained connection will cause the rest of the points along the circuit to not work. Just like a series circuit.

It is indicative of a bad receptacle and/or connection tap which can damage the appliance and anything downstream.

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