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ground wire question

Discussion in 'Electrical Engineering' started by DJ, Jun 5, 2004.

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  1. DJ

    DJ Guest

    "w_tom"
    How can I have this "intermittent arcing wire inside walls" checked out?
    Would I need an electrician to check this or is it something I could do?
    Thanks,
    DJ
     
  2. DJ

    DJ Guest

    http://ka9wgn.ham.org/ |
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  3. DJ

    DJ Guest

    Phil
    Thanks for this information. There's lots for me to learn about electric,
    isn't there?
    DJ

    http://ka9wgn.ham.org/ |
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  4. DJ

    DJ Guest

    Greg
    I do have 2 separate hard drives, that I switched out and still had the
    problem.
    How would I change to half the memory?
    Thanks DJ
     
  5. DJ

    DJ Guest

    Phil
    I have heard people mention this, "power off" I have always shut down from
    within Windows, START, TURN OFF COMPUTER, etc. How would I go about powering
    off my PC?
    Also, I don't have a reset button.
    Thanks once again, DJ

    http://ka9wgn.ham.org/ |
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  6. DJ

    DJ Guest

    Hi Kilowatt
    I've tried that.Maybe I should try a totally different wall socket.
    Thanks DJ

     
  7. DJ

    DJ Guest

    Kilowatt
    Hi, I mentioned changing to a different wall socket (outlet) in my other
    email to you. I must have read your mind.
    Will try that tomorrow.
    Thanks, DJ
     
  8. DJ

    DJ Guest

    Dave
    Hi, thanks for your response, "isolate emi filters in PC power supplies".
    Is there any way to have this tested?

    Thanks, DJ
     
  9. w_tom

    w_tom Guest

    Important to remember - PC is still powered even though it
    is turned off. The only fully powered off PC is one with the
    wall plug removed. Never remove or install anything inside a
    computer with power plug attached to wall receptacle.

    Notice that power switch is push button. There must be
    electronics to monitor that switch. When electronics sees
    switch temporarily pressed, then 'monitoring' electronics
    orders the power supply to turn on. IOW there is always power
    in that power switch 'monitoring' electronics. Only way to
    completely remove power from motherboard, power supply control
    circuit, and some peripherals is to pull power cord from wall.

    Removing computer components with power still on motherboard
    may damage components or motherboard.
     
  10. w_tom

    w_tom Guest

    One indication of internal and intermittent wire problems is
    how severe is the dimming. Placing a heavy load at the end
    of that circuit may tend to aggravate the problem. With a
    heavy load, then voltage at end of that wire would be
    significantly lower (which means of course you have the
    necessary too - 3.5 digit multimeter).

    Heavy load (ie electric heater) at end of circuit would also
    cause a noticeable dimming of incandescent lamps that share
    same circuit - if wire in wall is a problem. Dimming of
    lights means something is wrong or weakened.

    Electrician could discover why problem exists. But more
    important is to first make the problem reproducible - so that
    you have something to show the electrician. Better you do the
    easy labor rather than have him do it at electrician rates.
    Take inventory of what is on, what is off, and what changes
    (on to off, or off to on) when dimming occurs.

    Seriously consider having a new circuit run to that computer
    so that computer has a safety ground, as computer was designed
    to need. Safety ground (or GFCI) should also be in kitchen
    and bathrooms. Additionally, electrician could install the
    upgraded (required since 1990) earth ground and a 'whole
    house' protector. Minimally acceptable protector can be
    obtained at Home Depot for less than $50. Some electricians
    instead install an undersized Square D protector that costs
    much more money.

    IOW give him enough that he can create and therefore find
    reason for dimming. Then also take advantage of his arrival
    by having other basic stuff fixed. Even if kitchen grounded
    outlets are too expensive, still, get that earthing ground and
    'whole house' protector installed. Much cheaper to have done
    when you have already paid for his traveling time on this
    dimming problem.
     
  11. w_tom

    w_tom Guest

    Line filters assume the safety ground (third prong) exists.
    If safety ground is missing, then sometimes run a finger
    lightly on metal chassis and feel the 60+ AC volts - a sort of
    tingle. This 'stray' voltage might cause your power supply
    control circuit (on motherboard) to lockout. But that would
    be unique to each computer design.

    If leakage is causing your problem, then running computer in
    an receptacle with safety ground (third prong) would
    completely eliminate the problem. As I noted elsewhere, the
    computer was designed *assuming* the safety ground exists.
    You have no way to test that this is a problem other than
    running computer in a properly safety grounded circuit and
    observing no more failures.
     
  12. Guest

    You're busily chasing down a "PC problem" when the place you should
    be looking is in your sentence above.

    Forget the PC for a moment. Fix the flickering problem, for
    2 reasons:
    1) It could kill you
    2) It is likely causing the PC problem.
     
  13. DJ

    DJ Guest

    "w_tom"
    Hi, I've never had any problem with the lights dimming in this room. In
    the kitchen, the light over the table flickers occassionally, also sometimes
    when I use the microwave it will make the light over the sink flicker. I
    will have this outlet checked to make sure it is working correctly, then
    will let the newsgroup know if I still have problems. My PC doesn't shut
    down everyday, I never know when to expect it. So it may take a few days
    before it happens again.
    Is it possible to add a new circuit with a ground just in one room of the
    house? if there is a problem with this outlet?
    We have a new Home Depot close by, so I will check and see if they have
    the protector you mentioned.
    Thanks again, I appreciate the help.
    DJ
     
  14. Guest

    DJ wrote:
    Yes, but ground is not your problem. PC's do not need ground to operate
    properly. PC's are grounded for safety. Consider a laptop - the line cord
    is two wires with no ground prong - it has no ground connection, yet
    performs
    all the same functions as a "regular" PC.

    A surge protector won't address your problem, either.

    Address the flickering problem first. If you still have a problem
    with the PC dropping power after the flickering problem is resolved
    post again.
     
  15. Kilowatt

    Kilowatt Guest

    I think I would take the computer to a friends house and find out if it is
    your computer or you house.
     
  16. w_tom

    w_tom Guest

    I have seen where a computer would not work only when
    plugged into a house where someone had cut off all safety
    ground wires in the breaker box. If computer comes with a
    safety ground wire, then computer is designed on the
    assumption that safety ground will exist. If that safety
    ground wire is not connected, then stray 60+ voltage might
    exist - which causes other problem and failures when computer
    is connected to peripherals.

    Some computers have worked just fine without that safety
    ground. I have seen another fail due to no safety ground. We
    know (even from the HP Laserjet II experience) that missing
    safety grounds can cause hardware failure.

    Will safety ground fix the problem? Maybe yes; maybe no.
    Just because a laptop designed only to work on two wires
    exists does not mean that a computer designed for three prongs
    will not fail on two prong power. Those two computers (the
    three prong verses two prong) are designed differently.

    A surge protector is not to fix the problem. The surge
    protector recommendation was because an electrician was
    already paid to appear, will already be working inside the
    breaker box, and should also be utilized to upgrade earth
    ground and install 'whole house' protector. Recommendation
    made to maximize value of an electrician for long term benefit
    to computer and other electronics.
     
  17. w_tom

    w_tom Guest

    There is a major difference between dimming verses
    flickering. This is why any response to your problem can be
    difficult. No light anywhere should flicker when the
    microwave is turned on. Was the light flickering or dimming?

    You can have a dedicated circuit with ground installed
    almost anywhere inside the house. Does the washing machine at
    other end of building cause computer to fail when it starts a
    spin dry? These are symptoms you are watching for. What was
    happening anywhere else in the house when computer crashed?
    Important symptoms that only you can answer. Symptoms that
    may or may not answer you mystery.
     
  18. Guest

    Tom - for lord's sake - he's got flickering lights. In addition, his PC
    powers off.
    How on earth can a missing ground casue either one of those problems?
    Which problem presents greater risk to him?

    Your presentation contains no facts, and invalid assumptions. Saying
    a "stray 60+ voltage might exist" is a non-specific, unsupported
    speculation. It does not state where the voltage is, why the figure
    is 60+, where it came from, and whether it is a "bad thing", a
    "good thing", or an interesting but irrelevant item. Aside from
    the power supply, the electronics is NOT designed with a three prong
    plug in mind. That third wire is there for safety. The NEC does
    not allow you to consider the grounding wires as a current carrying
    conductor (article 400-5 1999 NEC) - a manufacturer must not
    intentionally introduce any current to that grounding conductor.
     
  19. w_tom

    w_tom Guest

    Does he have flickering lights or just dimming lights?
    Until he answers the question that was posted previously, then
    do you really know?

    In the meantime, 60 Hz AC leakage voltages can cause
    problems with the power supply controller on motherboard on
    some computers. I have seen it as previously posted. If you
    don't why it can happen, well then you were not a digital
    logic designer (IOW where does that leaking 60+ AC go?).

    Instead of invoking the lord, look at the original post. He
    asked if missing safety ground can cause computer problems.
    The answer is yes. In addition to addressing the flickering
    light problem (which was already done and apparently does not
    occur when computer has problems), he also has a potential
    problem that is described as quoted:
    Yes, a missing safety ground, in some cases, can also create
    this problem AND cause hardware damage. Will you focus
    blindly on the flickering lights and ignore all other
    potential reasons for that computer problem? The flickering
    lights possibility has already been addressed and is awaiting
    further information from the OP. No reason for you to now
    bring the Lord's Sakes into this discussion.

    Yes that third wire is for safety. But some designs use it
    to carry away the 60 hz leakage. You have never seen an Intel
    USART destroyed because that leakage (120 microamp) 60+ volts
    found another path when safety ground was missing? USART
    damaged, in part, because safety ground was missing -
    irregardless of the lord's sake.
     
  20. Guest

    I snipped most of your rambling post, but the part I left represents
    the major problem I see with what you posted.
    1) His PC is not connected to ground, so we can dismiss a spiking
    ground as the problem.
    2) You kept dragging the neutral in. I never mentioned
    neutral. In addition, it seems you think that the grounding conductor
    will carry current when the neutral breaks - you said :
    The ground conductor is there to conduct fault current. In the
    absence of any other defects, the ground conductor will NOT
    conduct current when the neutral opens.

    You mention a break on the neutral, fluorescents "seeing" 60 volts
    instead of 120 and so forth. I agree - a problem on the neutral can
    certainly cause the PC to drop power. But the issue is not a
    problem on the neutral - it is whether or not a missing equipment
    grounding conductor can cause a PC to drop power. It cannot.
    You need some other problem aside from a missing egc to
    cause a PC to drop power when it shouldn't.
    do with the neutral
     
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