Funky Wiring and Other Notes

Discussion in 'Architecture & Engineering' started by Tiassa, May 4, 2012.

  1. Tiassa Let us not launch the boat ... Staff Member

    Declining Standards: Funky Wiring and Other Notes

    To describe briefly a suite of three rooms: A bedroom with walk-in closet, a bathroom, and a small common room.

    There is something amiss about the wiring in the entire house. Recently, it was discovered that the reason the heating system didn't work correctly was that every forced air unit was wired incorrectly. One worked when the fan was set to low power, but tripped the circuit breaker if switched to high. Another actually sparked if you tried to set it on high. None of the rest of the fans, spread over three levels, worked at all.

    But in this suite of rooms, there is a weird issue that trips the breaker. If the computer powered through an outlet on the east wall is on, and the fan in the bathroom to the west, some set of circumstances will eventually bring down the power to the bedroom and the bathroom.

    However ... while the power drops in the bedroom and walk-in-closet, the outlets on the south wall—shared with the common room—are apparently unaffected. Additionally, one electrical outlet in the bathroom—on the south wall, which is situated against the stairs to the main floor—remains operable.

    The correlation of east-wall computer and bathroom fan is not consistent in and of itself. Two potential factors identified are whether the east-wall computer is spinning its hard drive—no, really, the thing will sit active and idling just fine, but if the drive spins up, the breaker trips—and the fan in a now correctly-wired heat register in the common room is on. The register is on the common room's north wall, which is the shared south wall of the bedroom, which in turn is part of what remains unaffected by the breaker trip.

    I have yet to pin down everything that needs to happen in order to willfully reproduce the phenomenon, but it's just weird.

    On another note, appliances such as the microwave and washing machine are breaking at an alarming rate; that is, within two years.

    And that part isn't just this particular townhouse. Complaints in this developed community have been pouring in. Refrigerators, gas ranges, laundry dryers—and just about everyone seems to loathe the heat system, which, even when it's working properly, doesn't work. At least one hot water system has been replaced.

    Of that we might simply shake our heads and wonder what ever happened to the idea of product quality in the American marketplace.

    But even setting that aside, I'm starting to wonder who the hell the subcontractor brought in to wire the place.

    I'm not particularly worried about a fire hazard; the circuit breaker might be lightweight—it's all fifteens and twenties, and in my youth I recall seeing thirties and forties (often dual fifteens or twenties) in home circuit breakers, especially when the circuit covers more than one room. But I still can't figure why the two outlets on the south wall of the bedroom and the one outlet on the south wall of the bathroom are unaffected when the breaker trips.

    It's just annoying. Miles Wilson once described Volvo electrical systems as "designed by a German engineer who subscribed to Gurdjieffian electrokinetics and had never forgiven the Swedes their neutrality in World War II". This isn't quite the same thing, but still, it's strange and annoying.

    Say what you want about shutting down your computer when you're not using it in order to not waste electricity; you're probably right. And say what you want about using workhorses for the computers that are either old or really old; you're probably right. Still, though, the problem existed before the second computer arrived, and it's only because of the second computer that I noticed the south wall of the bedroom still had power. And it's only a damn night light that informed me that the south wall of the bathroom still had power.

    It's just really bizarre, and really, really annoying.


    Wilson, Miles. "Wyoming". The Iowa Award: The Best Stories From Twenty Years. Ed. Frank Conroy. Iowa City: University of Iowa Press, 1991. Print.
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  3. Repo Man Valued Senior Member

    My first assumption was that the home in question must be old, but further reading suggests it isn't?

    I recommend one of these first off outlet tester.

    Making sure that the outlets are grounded, and have correct polarity is quick and easy with one of those.

    Many things end up plugged in to GFI outlets that shouldn't these days. I once had a call about a non working refrigerator in a garage. I found a dead outlet; but none of the circuit breakers were tripped. It turned out that the grandson had tripped the GFI outlet in an upstairs bathroom with his hair dryer that morning, and in his hurry to get to school he hadn't reset it. The outlet in the garage was on the same circuit.

    Modern appliances are just as picky as computers these days when it comes to requiring properly grounded and polarized outlets. Of course, even when they are powered correctly, failing after less than two years isn't at all unusual.

    The obvious answer to me about the unaffected outlets is that they are on a separate circuit breaker. Knowing that is one thing - actually figuring out what circuit breaker they are on is another matter entirely.
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  5. Aqueous Id flat Earth skeptic Valued Senior Member

    Where exactly did you see sparks coming from? (Thermostat, motor, contactor (relay), junction. . .?)

    Did the power ever seem normal, or did this start after the heater was rewired?

    Is this an old building that has been upgraded to handle more outlets and power demand (extra circuits/breakers)?

    What is the longest span of wiring, from breaker box to the farthest outlet, in your estimation?

    The first thing that comes to my mind is a design defect, in which two circuits share a common leg, and each circuit "sees" a droop in voltage when the twin circuit is pulling substantial power. This would tend to be more noticeable over long spans of wire.

    One thing that needs to be done is to find and label (in a list) all the outlets and fixtures in the house according to each breaker you have, and note the voltage and current for each as written (hopefully) inside the breaker panel.
    Also note the power draw at each outlet and fixture.

    I would guess you are operating at a marginal overload across a long span in which the voltage droops before the breaker trips. And since adjacent circuits are sensitive to each other, the main droop is probably across a common leg. There might be a way to balance the load simply by moving one of the larger loads to the adjacent circuit.

    Suppose you have a 20 amp circuit, and you figure out your PC is drawing 2 amps. That's only 10%, but if it puts the circuit at full load, while the adjacent circuit is only pulling 80%, then by simply running your PC from the adjacent circuit, you would have them both at 90%.

    That may not be convenient, and obviously turning things on and off varies the load anyway, so you would have to experiment.

    All of this is moot if you have some other problem, but it's something to consider.

    You might want to get a voltmeter and go around and take measurements. You can measure the voltage across hot and neutral, the voltage from ground to neutral, and ground to hot. Any substantial voltage from ground to neutral means that somewhere upstream is a load, and the neutral leg is sagging on account of it. Ideally, neutral to ground would read 0 V.

    Although you correlate line power fluctuations with your disk drive, it may be that multiple devices are coming out of power save mode at the same time as a disk seek operation, such as booting up, logging on, coming out of screen save or hibernation, or any other time it wakes up out of idle and starts burning CPU cycles, activating the screen and fan, etc. You can test this by going into Control Panel and playing around with the real time graphs in the Performance Monitor screen.
    Last edited: May 5, 2012
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  7. auser Registered Senior Member

    What type of breakers are installed? It sounds like older wiring and possibly new breakers, maybe arc fault breakers? They will trip quite often on older devices and are designed to detect arcs and shut off the circuit even if it isn't close to an overload.

    The first step I would take would be to identify every breaker to all of its outlets and lights it protects. Then take voltage readings while loads are connect, like your computer and bathroom fan at all locations.

    I suspect loose connections, especially with the neutral leg. Often times you will have two separate circuits that share a common neutral, and if there is a poor connection in the neutral it will cause voltage fluctuations in both hot legs anywhere from 0 - 240v (both adding up to 240v total) when they should be only 120v each! Some computer power supplies can take those voltages ranging from eg. 90 - 240v no problem but almost all other devices cannot. This could also be why other appliances are often failing, not getting the proper voltage, over or under voltages can destroy them.

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