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All the devices on one of my breakers randomly stop working, and when checked with a multimeter, I see that the outlets are giving a voltage of ~8V rather than the ~125V I usually get. When I check that breaker at the panel, I get ~125V as I should.

What's extra strange is that this seems to be associated with my dryer, but I can't imagine how. The dryer is on a totally separate breaker from the one that keeps dying. But when this happens, I have to flip the dryer breaker and the other one, and then turn on the dryer, and then boom all the other devices power up again the second I turn start the dryer. I've done this three times now, so I really doubt that it's just coincidence.

Note: My dryer is ghetto rigged. It has two dials: an on-off dial and a timer dial. A while back, the on-off dial stopped working. I opened up the dryer, and hardwired past on-off button so that it just starts as soon as you move the timer dial. In doing so I left a third wire that was connected to the on-off button just hanging out - unconnected with electrical tape covering it. I did check to make sure that the chasis was still grounded. That "fix" has been working for 7 months before issue started. I'm not sure if its related, but I just want to give as much info as possible.

Any thoughts or ideas are appreciated - Thanks!

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    How are you testing the voltage? Test all possible combinations: hot to neutral, hot to ground, neutral to ground. Also unplug the dryer to eliminate it as bring part of the problem. (Also fix your dryer properly. Or at least make sure you have a working smoke detector in the laundry room...) – Grant Oct 1 '15 at 3:05
  • So in answer to the first comment, I'm testing the outlets, with a multi-meter between the positive and negative prongs. – Stephen Hartzell Oct 1 '15 at 12:06
  • In answer to the second comment, I don't think that its just voltage coupling, because I tried an experiment similar to what you said. I connected my coffee maker to the outlet reading ~8V and the hex display that reads time lightly displays and flickers. Upon doing the voltage reading between its two prongs is 8V. – Stephen Hartzell Oct 1 '15 at 12:07
  • Good experiment! I retract my comment :) – bitsmack Oct 1 '15 at 16:45
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You have an intermittent open leg on your electrical service. By turning on the dryer you are creating a backfeed through the heating elements which is a 240V load that uses both legs of your service.

An open service neutral would show with the voltages in the house going both up and down. Meaning you might get 50V on one leg but 180V on the other.

I'd start by calling the power company to see if the problem is on their end of things.

  • Thanks so much for the reply! I am wondering though, why I would only see this issue with devices on one breaker if it were a problem on the power company's side of things? Wouldn't that effect all the outlets in my home? – Stephen Hartzell Oct 1 '15 at 12:09
  • Yes, that would affect about half the outlets in your home. This is not likely a problem with the main service. – user39367 Oct 1 '15 at 16:52
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    The fact that the dryer causes a backfeed tells me it is a service leg, and not just one circuit. – Speedy Petey Oct 1 '15 at 18:33
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    Thanks so much for your reply, from what I'm finding that sounds the most likely, and I've taken you up on your advice to call the power company. – Stephen Hartzell Oct 2 '15 at 0:55
  • If it were an actual backfeed through the drier, the voltage on the bad leg would certainly be very very wrong and the drier would not operate correctly (having at most 120v available and not 240v). I cannot imagine that the affected receptacles would appear to function normally either, whether or not the drier was on. – user39367 Oct 2 '15 at 3:26
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Disregarding the clothes dryer, what you describe sounds like an intermittent neutral connection. To check for this, next time the circuit fails go to an affected duplex receptacle and plug in a hair dryer to one outlet and turn the hair dryer on HIGH (the hair dryer will not run during this test, obviously). Use your volt meter to check the other receptacle in the pair between neutral and ground (the longer straight slot and the center roundish hole). If you read approximately 120v between neutral and ground during this test, then you have an intermittently bad neutral connection in your house wiring.

If you confirm it is a bad neutral connection, then the trick is finding it. The dryer is a clue. The dryer is a high amperage appliance. In industrial settings with much larger equipment there are circumstances where the wires in a single raceway will physically jump when a high current is suddenly transported due to the EMF of the current. My best guess is you might have something like that. The wiring from the dryer is in close proximity to the loose neutral, and when you start the dryer the wiring twitches enough to make the loose connection.

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