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Power Surge & Blown Fuses

Discussion in 'Electronic Repair' started by [email protected], Sep 15, 2006.

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  1. Guest

    We had a power surge, a rather large one. It trip most of the breakers
    in our panel and al surge protectors trip. All but one TV did not power
    up again. The electrician who came in to check our panel(wanted to make
    sure everything was ok) stated that most of the TV's fuses did their
    jobs and that I should just open and replace them.

    Not too sure, but I did open one of them, Toshiba 14" 14AF46 (< 6
    months old) and the fuse where the power comes into the board was
    blown. It is a 125V/6.3A. My background is with computer boards from a
    PC side and not with TV's. Before I go and waste my time and make the
    repair more costly, could it be as simple as replacing the fuse? If so,
    where would one normally purchase these fuses, not a common type.

    The only TV that turns on still is a Sony KV-36XBR250. The image is
    black and gray(can't really say white) and everything looks like a
    hazy, reversed, indented images. The sound is fine. Is this TV toast?
    Better to trash and replace?

    I have replaced fuses before on two older tv's several years back, but
    I am not sure about this newer TV.

    Any advice is greatly appreciated.

    ER -
     
  2. L.

    L. Guest

    IF the power surge was a result of the Power Companie's equipment and you
    can somewhat prove it, THEY may end up repairing or replacing your set.
    I've seen it done locally. Give them a call.

    L.
     
  3. James Sweet

    James Sweet Guest


    Replace the fuse *once* with one of the *correct* rating and try it. If
    it blows again then you have further damage.
     
  4. Jim Land

    Jim Land Guest

    wrote in @i42g2000cwa.googlegroups.com:
    I thought that this is exactly the situation surge protectors are supposed
    to guard against. Aren't they supposed to sense the surge and trip their
    own breakers *before* the surge gets to whatever is plugged into them?

    How did the surge make it through the surge protector and into the tv to
    blow the fuse?
     
  5. w_tom

    w_tom Guest

    Fuses require tens of milliseconds to trip (blow). Surges do damage
    in microseconds. Fuses and circuit breakers don't stop or block surges
    - too slow. Circuit protection devices trip to protect humans after a
    higher energy source (AC electric) powers through damaged appliances.

    Try replacing fuses. Fuses are cheap. You may get lucky. But
    protecting hardware from damage is not from a fuse / circuit breaker
    purpose - too slow.

    Meanwhile, if utility failure (as another suggested) created high
    voltage, then utility should pay. Any linemen working in the area?
    Unfortunately, you must provide some reason for the utility to accept
    blame.
     
  6. Bud--

    Bud-- Guest

    Power system surge suppressors are usually based on MOVs. A MOV clamps
    the voltage between 2 wires (like a bidirectional Zenier diode). The
    clamp voltage is low enough to not damage equipment connected
    downstream. If you have a surge on an incoming hot wire and you clamp
    the voltage from hot to neutral in a service panel, the voltage on the
    neutral tries to rise. Since the neutral is connected to ground/earth in
    a US service panel the surge is shunted to ground. Currents of thousands
    of amps can result, but max few millisecond duration since a surge is by
    definition a short duration event. Effectiveness of protection depends
    on the current and duration of the surge versus the ratings of the surge
    protector. Plug-in surge protectors may have low protection ratings.
    MOVs hit with surges near their ratings will deteriorate and eventually
    fail.

    High earth current will locally raise the earth potential. If other
    connections, like CATV, do not have their entry protectors tied with
    short connections to the neutral-ground connection point at the
    electrical service, thousands of volts can appear between power wires
    and CATV. If a plug-in surge suppressor is used, the CATV, phone and
    other wiring to a device has to go through the suppressor so all wires
    are clamped to the common ground at the suppressor.

    A good guide on surges and protection from the IEEE is at:
    http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf

    and from the NIST at:
    http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf

    bud--
     
  7. James Sweet

    James Sweet Guest


    Surge protectors are largely snake oil, they can help some in some
    situations, but a severe surge will blast right through one. The circuit
    breaker in the surge protector is far too slow to trip in time to fully
    protect the device.
     
  8. w_tom

    w_tom Guest

    James Sweet introduced reasons why a plug-in protector does not
    provide protection. Protectors don't stop, block, or absorb surges.
    To do that, a protector must be a series mode device. But it is a
    shunt mode device. Protector is effective if it shunted (connected,
    diverted, clamped) a surge to earth. But protectors without earthing
    (a problem when adjacent to the tv) cannot be effective. No numerical
    specifications for each type transient are published by that protector
    manufacturer. Even manufacturer does not claim protection you assumed
    existed. So myths are promoted based upon word association: surge
    protector sounds like surge protecction - therefore it must provide
    protection.

    A surge not earthed before entering a building may overwhelm
    protection already inside the tv. One effective protector (because it
    is earthed) for all household appliances that costs only $1 per
    protected appliance and that is provided with responsible manufacturer
    brand names such as Square D, Siemens, Cutler-Hammer, Intermatic,
    Leviton, or GE. How much did you pay for a protector that was too
    small and does not even claim to protect? A daming statement. Where
    are numbers that define proetction?
     
  9. True only if you have surge suppressors that rely on breakers for
    protection, in which case it would not be considered a surge suppressor,
    otherwise bullshit. Virtually all surge suppressors now use MOVs. They are
    effective if adequately designed and installed. Do some reading in Bud's
    links and look at how the better surge suppresors are designed.

    Leonard
     
  10. bud--

    bud-- Guest

    James Sweet's comments appear to be applied to all surge suppressors
    and provided no reasons why they don't work, unless you have changed
    your mind and think protectors work by using circuit breakers.
    As is clear from the IEEE guide, plug-in protectors work primarily by
    clamping, not series mode, shunt mode, stoping, blocking or absorbing.
    Your religous view that "protectors without earthing ... cannot be
    effective" appears to prevent you from understanding the IEEE and NIST
    guides.
    I am astounded that SquareD is on your list of "responsible
    manufacturers" since their literature does not provide "numerical
    specifications for each type transient". Please review the other
    manufacturers and provide a link to "numerical specifications for each
    type transient" from one of them.

    The IEEE and NIST guides clearly say that plug-in suppressors are
    effective.
    Links to sites that say plug-in suppressors are effective: 2
    Your links to sites that say plug-in suppressors are not effective: 0

    bud--
     
  11. w_tom

    w_tom Guest

    Amazing that bud still posts his ... well bud represents interests of
    plug-in protectors manufacturers. He cites a papers that demonstrate
    an SRE concept, defines notes how the concept is compromised, and then
    recommend the well proven and recommend protection method (ie 'whole
    house' protection). What does effective protection have and plug-in
    protectors don't? Dedicated earthing connection. From a conclusion in
    bud's own citations:
    What does NIST and IEEE recommend?
    Bud simply distorts a paper that says SRE protection (a protector
    without earthing connection) can work. Bud forgets what that paper
    says; that even a kid with an Xbox can violate that protection.
    Remember, bud promoted plug-in protector manufacturers. Effective
    protection is defined by IEEE Red Book (IEEE STd 141) and IEEE Green
    Book (IEEE Std 142):
    Meanwhile, author that bud repeatedly cites also says that plug-in
    protectors can even contribute to electronic damage:
    Paper that bud cites do not say that plug-in protectors are
    effective. Bud cannot even define effective - so that he need not
    admit why plug-in protectors are both ineffective and so often grossly
    overpriced. Bud's own citations even say the properly earthed
    protector is a superior solution. Bud intentionally would confuse you
    by citing the concept, then proclaiming a technical description as a
    recommendation. This post but again a warning about those who promote
    grossly overpriced and typically undersized protectors - that are so
    profitable.
     
  12. Bud--

    Bud-- Guest

    To quote w_: "It is an old political trick. When facts cannot be
    challenged technically, then attack the messenger.." I have nothing to
    do with surge protectors.
    The guides don't mention Xboxes. In case anyone doesn't understand w_,
    he claims the guides say using a SRE requires difficult engineering,
    considering the whole room. The guides show simple application of SREs.
    Claiming difficult application is stupid.
    To take only one example: the IEEE guide, chapter 6, "Specific
    Protection Examples," shows 2 examples of surge protection. Both use SREs.
    Saying both guides waste a lot of space describing SREs that are not
    effective is stupid. Repeatedly making this claim requires willful stupidity


    The IEEE and NIST guides clearly say that plug-in suppressors are
    effective.
    Links to sites that say plug-in suppressors are effective: 2
    Your links to sites that say plug-in suppressors are not effective: still 0

    bud--
     
  13. I saw a photo of a cheap suppressor that had clearly had a serious hit. It
    was hidden behind furniture and the customer didn't know until he moved
    because the equipment continued to run OK.
     
  14. Bud--

    Bud-- Guest

    The IEEE guide talks quite a bit about wiring the protected load across
    the MOVs, which will disconnect the load when the MOVs are disconnected,
    or wiring the protected load so it is not disconnected. There are
    potential advantages both ways. I believe UL now requires suppressors
    that don't disconnect the load with the MOVs to state that (could be in
    the guide).

    UL also now requires MOVs that overheat be disconnected. Before the
    change plug-in suppressors could melt the plastic case.

    The former NIST guru on surges, who wrote the NIST guide, has said most
    MOV failures (I presume service panel and plug-in) are a result of
    overvoltage, not surge.

    bud--
     
  15. w_tom

    w_tom Guest

    IOW plug-in protectors are for profit - not for effective protection.
    Many are grossly undersized. When it fails or vaporizes (operates
    outside of what MOV manufacturer datasheets define for acceptable
    operation), then that protector is recommended by the naive to the
    naive - more sales. Best to make plug-in protectors undersized. Ask
    yourself. Do you want these devices behind a desk or on the rug.
    These are what Bud is promoting as effective protection:
    http://www.hanford.gov/rl/?page=556&parent=554
    http://www.westwhitelandfire.com/Articles/Surge Protectors.pdf
    http://www.ddxg.net/old/surge_protectors.htm
    http://www.zerosurge.com/HTML/movs.html

    Just another reason why 'whole house' protectors are so effective.
    Properly sized so that the surge is earthed - and homeowner never knows
    a surge existed. That is how surge protectors performed even 50+ years
    ago.

    They don't have the necessary earthing connection. They must do
    something to sell their ineffective products. One way is to undersize
    the protectors. However, that can have dangerous consequences.
     
  16. Bud--

    Bud-- Guest

    As you very well know, and as I stated in the quote above, UL "now
    requires MOVs that overheat be disconnected." Your scare tactics are
    pathetic.

    One can certainly get undersized protectors. That is why the IEEE and
    NIST published guides, and why I posted links to them.
    And the required statement of religous belief again. As the IEEE guide
    explains to those who can read, plug-in suppressors work primarily by
    clamping, not earthing.
    The IEEE and NIST guides clearly say that plug-in suppressors are
    effective.
    Links to sites that say plug-in suppressors are effective: 2
    Your links to sites that say plug-in suppressors are not effective:
    still 0
    63,458,237 pages on the internet and noone agrees with you???

    bud--
     
  17. Guest

    You appear to confuse popularity with proof.

    If you want to understand something, asking those with $ to make out of
    it is not the way. The route to knowledge is to ask those with skills
    qualifications and experience in the science and engineering of the
    matter.

    Obviously those with $ to make will seek to convince potential buyers
    of the value of their overpriced undereffective products.


    NT
     
  18. w_tom

    w_tom Guest

    Facts that Bud routinely forgets to mention from his citations.
    Figure 8 from his own citation shows two televisions connected a
    plug-in protector. Both televisions then go to 8000+ volts during a
    massive surge. Somehow Bud assumes this is protection. Somehow, Bud
    assumes other conductive materials in that room (floors, walls, other
    AC receptacles, pipes, etc) do not compromise that protection. Somehow
    Bud claims that equipotential alone provided protection. And so Bud
    routinely forgets a very first conclusion made by Martzloff, et al in
    an IEEE paper:
    Do we install expensive plug-in protectors even for dishwasher, smoke
    detectors, bathroom GFCI, clock radio, dimmer switches, etc? Of course
    not. We spend tens of times less money for a protector that does both
    equipotential and does conductivity; what a plug-in protector cannot
    accomplish (because it does not have that earthing wire).

    One 'whole house' protector, properly earthed, provides both
    conductivity and equipotential for everything inside a building - at
    about $1 per protected appliance.

    Protectors properly sized so that these scary pictures need not
    occur:
    http://www.hanford.gov/rl/?page=556&parent=554
    http://www.westwhitelandfire.com/Articles/Surge Protectors.pdf
    http://www.ddxg.net/old/surge_protectors.htm
    http://www.zerosurge.com/HTML/movs.html

    Disconnecting undersized MOVs is a backup system. When protectors
    use grossly undersized MOVs then human safety is dependent only on a
    backup system.

    Bud promotes for the plug-in protector industry. He fears you might
    learn of those human safety threats and learn why that short connection
    to earth is essential. We don't stop or absorb lighting surges. We
    earth them so that appliance internal protection is not overwhelmed.
    We earth transients using a protector properly sized so that those
    scary pictures are irrelevant. Even Bud's own citation in figure 8
    shows televisions at 10,000+ volts when only using a plug-in protector.
    Somehow he calls that effective protection.
     
  19. Bud--

    Bud-- Guest

    For those who can read, the IEEE guide cited uses Fig 8 to explain how
    SREs work. For those who can read the IEEE guide clearly recognizes
    plug-in surge suppressors as effective.
    The application of SREs in the IEEE guide is simple and straightforward.
    Your claims that engineering expertise is required, considering the
    whole room is nowhere in the guides or any other paper and is willfull
    stupidity.
    One of the authors of the Upside-Down house papers was Martzloff, who
    wrote the NIST guide which recognizes plug-in surge suppressors as
    effective. Another author was Dr. Mansoor. Yor previous comments
    provoked the following from an EE:
    "I found it particularly funny that he mentioned a paper by Dr. Mansoor.
    I can assure you that he supports the use of suge equilization type
    plug-in protectors. Heck, he just sits down the hall from me. LOL"
    Progection decisions are a tradeoff of progection cost, risk and value
    of protected equipment. Protecing a clock radio wouldn't make sense.
    Protecting a home theater system does. As does protecting a computer,
    primarily because of the value of the data and software contents and the
    time required to set up a new one.
    And the required statement of religious belief.

    A repet of your pathetic scare tactics. As stated previously, UL
    standards now require disconnect of failing MOVs.
    And the political trick back again.


    The IEEE and NIST guides clearly say that plug-in suppressors are
    effective.
    Links to sites that say plug-in suppressors are effective: 2
    Your links to sites that say plug-in suppressors are not effective: still 0

    bud--
     
  20. Bud--

    Bud-- Guest

    I really don't understand your comments. What I have said is
    consistently based on the IEEE guide at:
    http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf
    and an equivalent guide from the NIST at:
    http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf
    They guides were writen by 6 EEs as guides to the general public on
    surges and surge protection. I don't where you could better find people
    with "skills qualifications and experience in the science and
    engineering of the matter" than the IEEE and NIST. The author of the
    NIST guide has written many published papers on surges and protection.

    I have not quoted "those with $" in this thread and have never used them
    as authorities.

    bud--
     
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