89 - 90 volts at Outlet

Discussion in 'Electrical and Wiring' started by brewer55, Dec 19, 2013.

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  1. Dec 19, 2013 #1

    brewer55

    brewer55

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    I just moved into a new home and have discovered that 2 separate outdoor receptacles (2 locations near each other) both weren't working. When I put an AC meter on the outlets, both showed a voltage of ~90 volts. Is this indicative of a loose or broken wire somewhere?
     
  2. Dec 19, 2013 #2

    bud16415

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    If your meter is reading correct, verify by checking a good known 120 V outlet. I would say not broken maybe loose but most likely corroded and that would be most likely someplace outside where wires are connected wire nuts or under screws.

    That would be my guess if they once worked and now they don’t. you said new home is that new to you or new construction?
     
  3. Dec 19, 2013 #3

    Wuzzat?

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    A disconnected wire.
    It's a phantom voltage, and with voltages that close to 120v you probably used a high input impedance digital meter. A cheapie analog meter with sensitivity of 1000 ohms/volt would probably read lower, its input impedance on the 150v scale would be only 150 kilo-ohms.

    If it really is 90v then a small bulb (7-1/2w, 10w, 25w) should be somewhat lit.

    To find it, you'll have to know where that branch circuit goes, from source to end.
     
  4. Dec 20, 2013 #4

    nealtw

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    You want to prove that the meter is correct, then prove that you are getting 240 volts supplied to the house.
     
  5. Dec 20, 2013 #5

    JoeD

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    Look for a tripped GFCI. Probably in the garage behind the pile of stuff that hasn't moved in ten years.
     
  6. Dec 20, 2013 #6

    Speedbump

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    When were you in my garage???:)
     
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  7. Dec 20, 2013 #7

    brewer55

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    The house is 21 years old -- new to me.
    My first test was with a light tester (lamp on one end, 2 probes on the other). It lit up, but it was not as bright as when I tested an outlet in the house that was ok. That is when I used an inexpensive battery tester (digital) using the AC scale. So, it is apparently getting some juice, just not 120V.
     
  8. Dec 20, 2013 #8

    bud16415

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    The outlets should be on a GFCI circuit as Joe D pointed out the GFCI outlet most likely will be at another location protected from the elements maybe and these two are coming off of it on the load screws. As he mentioned maybe in the garage or something. It could be that GFCI outlet is having a problem. I’m far from an expert on those things but I understand the older ones had some issues and could fail in the open condition. Test it using the self-test check your outlets again even check that outlet and see what happens. They are not too expensive to try changing it out to rule it out. If you don’t have one then You will have to look in other places and you should think about adding one anyway.

    Your meter does read 120 when you take it in the house and check a good outlet?
     
  9. Dec 20, 2013 #9

    brewer55

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    Yes, it does read ~120 in a good outlet.
    Since my last post, I have done more investigating. There are 2 GFCI outlets in the garage. One controls an outside outlet (not one of the ones I'm have a problem with). I assumed that the other GFCI outlet controlled the 2 outlets by the deck that I am having a problem with but, it does not. I even pulled it out of the wall and in test, it opens the circuit and the voltage is correct.

    So, I still have to keep looking. I checked the breaker at the breaker panel and I did have a loose wire connection there. Probably, somewhere in the basement I'm going to find a loose wire nut or something like that.

    One more question. Is there a tool for electric circuits that puts a 'trace' on it with something like an audible tone? I know they make toners for low voltage wiring (phone line), but did not know how one traces out an electrical line short of line of sight.
     
  10. Dec 20, 2013 #10

    nealtw

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  11. Dec 20, 2013 #11

    bud16415

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    I have heard of getting low voltage out of a GFCI when the common got switched on the input side. Or something like that. Neal is correct make sure the feed is all done correct and the load wired out properly. But if you tripped both of them and you still had power to the ones in question it sounds like they are not the ones. Can you follow the wires?

    There are tone devices like Neal showed that work quite well. I have also seen guys make a flashing load using a 120 v heavy duty xmas tree light box and plug a 100 w bulb in and then use a clamp on amp meter and look for the wire that’s pulsing.

    Start by finding the breaker yes. Then you can trace it as far as you can both ways and look for things and clean up connections etc.
     
  12. Dec 20, 2013 #12

    brewer55

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    I found the issue. It was a tripped GFCI on the FRONT porch. I'm thinking that it is probably going bad if I was getting a voltage reading at all when it was in the tripped position.

    Anyway, thanks for all the advice. It prompted me to keep looking and I learned a little more about the power scheme for this house.
     
  13. Dec 20, 2013 #13

    Wuzzat?

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    Time may tell if it was a false trip or it tripped for a valid reason.
     
  14. Dec 21, 2013 #14

    brewer55

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    Thanks, Neil. I've not opened the culprit GFCI yet to see if it is either wired incorrectly or needs replacing. One more item on my list of things to do.
     
  15. Dec 21, 2013 #15

    bud16415

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    Don't even mess around with it change it out. If it was tripped and had 90 V on it. It wasn't really tripped off. The whole reason to have one is for your safety. Glad you figured it out.
     
  16. Dec 30, 2013 #16

    ohmy

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    Yes, they are called "toners" and you can get them at the box store. The only thing is you want to make sure the circuit is completely dead before you tone it and start from the beginning of the circuit.
     
  17. Dec 31, 2013 #17

    brewer55

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    Kind of defeats the purpose if you don't know where the circuit runs.
     
  18. Dec 31, 2013 #18

    Wuzzat?

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    I made up a spare 50A breaker with a cord and plug and an LED/resistor/diode power indicator.
    You plug it in the questionable outlet and switch it on and the smaller breaker feeding that circuit trips off. If it doesn't, the 50A trips off and then you know you have a defective breaker.
    I don't do this in customers' houses, only in mine.
     

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