Whole house surge suppressors

Discussion in 'A+ Certification' started by Flea Ridden, Jul 5, 2004.

  1. One can but hope.
     
    Mike Tomlinson, Jul 16, 2004
    #81
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  2. Flea Ridden

    daestrom Guest

    "Steve Alexanderson"

    Seems quite clear to me that the ground lug is only there to provide a
    grounding for wire sheathing. The NID is meant to be used for wire that has
    a metallic shield -or- a non-metallic cover. When a metal shielded cable or
    support wire is used, it is connected to the ground lug of the NID and the
    NID lug must be grounded. But if the phone drop does *not* use a support
    wire or shielded cable, there is nothing connected to the ground lug inside
    the NID. If you want to ground it, you are essentially running a ground
    wire to a terminal that is connected to *nothing*.

    Some may argue that having a grounded lug within an inch or so of the phone
    wires provides *some* kind of protection by allowing direct lighning surges
    to jump the small gap. But a voltage level needed to jump such a gap would
    destroy all the phones in your house. And it would be much higher than the
    protection devices at the pole would allow. So such a 'gap' argument is
    silly as it is no protection at all.

    Grounding the NID lug is only significant *if* the incoming phone drop uses
    shielded wire or support wire that needs to be grounded. They don't have
    internal surge-suppression/lightning protection. The use of the ground lug
    varies from one phone company to the next. It even varies within the same
    service area. The NID is designed for use with either type of phone drop
    (one with a metallic shield or without). But like many devices, this
    'feature' (the ground lug) isn't always used. It is only there for
    grounding the shield or non-circuit metallic components. If you have
    unshielded, tempered phone drop, there is no non-circuit metallic components
    to ground.

    daestrom
     
    daestrom, Jul 17, 2004
    #82
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  3. Flea Ridden

    w_tom Guest

    This protector as defined in the 1997 Demarcation Point
    Order was discussed in FCC Docket in 2000 in the paragraph
    entitled "Safety Concerns Regarding the Placement of the
    Demarcation Point Away from the Building". Petitioners were
    AT&T, GTE, Southwestern Bell (SBC), and TIA. Concerned was
    that, "locating the demarcation point a substantial distance
    from the building in which telephone wire is located could
    raise safety concerns."

    Petitioners further noted "that the National Electrical Code
    (NEC) requires the placement of surge protection at or near
    the building, these petitioners concluded that if a network
    protector is placed by the carrier at a demarcation point near
    the property line, and that demarcation point is a significant
    distance from the building, a second network protector should
    be installed where the wire enters the building."

    So what are they discussing if the protector does not exist
    or is not required? The protector is required by code as
    noted earlier AND the code even states how short a wire from
    protector must be connected to earth ground. Even the FCC
    states how close the protector must be to where wire enters
    building.
     
    w_tom, Jul 18, 2004
    #83
  4. Flea Ridden

    zxcvbob Guest


    Since the local building inspector agreed with the telephone company
    (even though I quoted section 800 of the NEC in my letter), should I
    just drop the issue? That's really not my style. Would I contact the
    state building inspector or the public utilities commission or the FCC?

    I suspect that none of them will want to get involved.

    Thanks again,
    Bob
     
    zxcvbob, Jul 24, 2004
    #84
  5. Your suspicions are probably correct.

    The FCC has nothing to do with it, so the state building
    inspector and the public utilities commission are your only
    choices.

    I'm not sure I see much point in doing that.

    I don't recall now just what the original interaction with the
    telco was, but the *first* thing one wants to do is thoroughly
    exhaust all avenues with the telco. I seem to recall it was one
    outside plant installer with an imagination who conjured up a
    story that was total bullshit, but to him sounded pretty good,
    that was the last contact?

    You need to discuss this with supervisors and engineers, and
    make repeated efforts at it, until you have nobody else you can
    pester. Keep logs of *exactly* who you talk to (the date, the
    time, and who they are and a short description of what they
    say). And make it obvious that you are keeping track too (they
    are also logging it, so don't worry about upsetting anyone).

    As long as you get unsatisfactory answers, demand to speak to
    someone who has more knowledge or authority. Be courteous,
    professional, and do not bluff anyone with anything.

    If you get to the point where you've talked to everyone who is
    anyone, *then* take the entire log to the PUC. What happens at
    that point depends very much on where you are. Some regulatory
    agencies are virtual rubber stamps, and will do *nothing*.
    Others will demand a _certified_ response from the telco
    guaranteeing that no rule or regulation is going to continue to
    be broken. (If you are the first, nothing else happens; but if
    they just certified the same thing six months ago, all Hell will
    break loose.)

    At no point do you want to hold your breath waiting for
    justice...
     
    Floyd L. Davidson, Jul 24, 2004
    #85
  6. Flea Ridden

    MC Guest

    Had an unterminated arial phone line running parallel below power lines for
    about 300 feet. Did not know was not connected, went to investigate open end
    dangling on power pole and got knocked off my feet!

    I never ran across this on short runs and most are terminated on one end or
    the other so did not think to check things out first.

    Anyway did not have a meter with at the time to see what the potential was ?
    I wonder how much current could be sinked from that source ?
    If I ever get a chance to find another situation like that, think I will do
    some testing to see.
     
    MC, Aug 5, 2004
    #86
  7. Flea Ridden

    Beachcomber Guest

    In some very remote parts of the world, parallel conductors are run
    for moderate distances along the right-of-way of high voltage
    transmission lines. The small amount of power from this linear,
    inductive tap is used to feed the power needs of small villages.

    Apparently, this is a cost-effective alternative to a substation.

    Beachcomber
     
    Beachcomber, Aug 5, 2004
    #87
  8. Flea Ridden

    Chris Lewis Guest

    The above is probably not related to my previous comments about induced
    voltages.

    An open (on hook) telco circuit often has, if I recall correctly, about 48VDC
    on it. Not a lot of amps (it's only 26ga or so after all...).

    When the phone rings, you're getting AC at 90V or even more. Which is why
    the old telephone set bell units work so nicely on 120V. It's close-enough
    voltage matched to ring without frying anything. Similarly, not much in the
    way of amperage.

    All the above means is that you can get a pretty compelling zap when you touch
    one depending on how well you're grounded. Ie: an extra line drop that's
    connected but not currently being used.

    As I demonstrated to myself a few months ago after trying to splice an accidentally
    severed phone wire while sitting on bare concrete... Not lethal this time,
    but strong enough to make it impossible to ignore. The SO could hear me cursing
    150' away thru two exterior walls ;-)

    But, remember, under certain (albeit rare) circumstances, even 48V can be lethal.

    That said, it is entirely possible that a phone line can become energized
    to much higher potentials.

    There's a story that went thru this group years ago about having phone
    service to an area in the US failing, and phone service people finding
    two smoking dead bodies underneath a severed phone trunk line.

    There was a moderately high resistance power fault from a nearby HV
    feeder into the trunk grounding sheath that was grounded well enough at
    the other end of the trunk to not present phone problems, and the fault
    wasn't big enough to trip the HV feeder's interrupter either.

    Two thieves tried to steal the phone trunk cable (for copper scrap).
    When they severed the cable and touched the trunk grounding sheath,
    _they_ became the grounding path. They weren't as robust as the
    grounding at the other end of the severed trunk line...

    So, it pays to be very cautious about wires hanging down from power
    poles, no matter what they look like.
     
    Chris Lewis, Aug 5, 2004
    #88
  9. A friend brought an old crank generator/magneto in to school one day.
    A bunch of us less sane ones (all male, of course) tooks turns giving
    and receiving zaps. Remember Bob and Doug MacKenzie in "Strange Brew",
    fighting over who would receive the electric shock therapy while in
    the mental institution? Like that. :)

    Tom
     
    Tom MacIntyre, Aug 5, 2004
    #89
  10. Flea Ridden

    Pop Rivet Guest

    Please set followups to your favorite group!
    It's silly to cross post to so many groups, especially in
    light of the misinformation presented here. Please refrain
    from doing so in the future and become a good netizen.

    You can look up any of the following at about any telco:
    they're all onine.
    Nor North America, Canada, Japan and a few other countries:
    -- Ring Voltages: 70Vrms to 90Vrms, NOT 90V "or more".
    The actual voltage will depend on the REN loading AND
    distance from the telco where the ring generator is located,
    plus any amplifiers in the line along the way to the
    subscriber. If it cannot leave the telco at >90Vrms, be FCC
    spec, it will never exceed that voltage anywhere along the
    line.
    -- Ring Voltage Current: Up to 100 mA by spec, on a short
    line, up to 120mA emergency power. It IS LETHAL!
    -- Ring Voltage Frequency: 20, 25, 30, 33, or 50 Hz,
    +/-5Hz. Most of the US uses 20 Hz +/- 5 Hz and most
    electronic telephone equipment is rated Class B, meaing it
    will detect ANY ringing frequency that is to spec. Cheapie
    crap only responds to about 12 to 28 Hz in my experience.
    -- Ring Voltage Pattern: Normally 2 S on, 4 S off,
    repeated. Other patterns widely used for special services.

    Pop
    ---
    Those who have nothing to say often say so.



    =-----
     
    Pop Rivet, Aug 7, 2004
    #90
  11. Ah...reminds me of one of my less-brilliant moments. Having a few
    suds, no meter available, cellular phone seemed to be not charging. I
    tongue-tested the adapter...only 10.6 volts, but with an 850 mA
    capacity. I don't know how many ohms it is on a small area of a human
    tongue, so I don't know how much current I was subjected to, but it
    felt like the top of my head was coming off. :)

    Tom
     
    Tom MacIntyre, Aug 8, 2004
    #91
  12. Flea Ridden

    Nostradamus Guest

    Sounds like the makings of new winner for the Darwin's award, especially if
    he starts stripping 120 v wires.
     
    Nostradamus, Aug 8, 2004
    #92
  13. Flea Ridden

    chuck yerkes Guest

    It's how you test 9V batteries. And my guitarist was a wuss.
    I never ENJOYED it, but I learned to do it quick and have the
    battery of the tongue before I realized taht I've got it.
    Better than the "jam in on your tongue and hold" technique.


    I never did the on-set grip's "trick" of pick up a 100A light outlet
    (which is simply 2 HUGE copper paddles with a box about the size
    of your fist). He said "you just touch it with the BACK of your hand
    and when the power hits you, the muscle contraction pulls it away."
    THanks, I'll just grab a meter.

    But you'll watch experienced electricians putting one hand in their
    back pocket or belt while working a breaker panels. Keeps away the
    temptation to grab a good ground pretty much guaranteing death if the
    other hand hits live. with the hand ungrounded, death isn't guaranteed.

    Pay for your friends to take CPR classes, a worthwhile investment.
     
    chuck yerkes, Aug 9, 2004
    #93
  14. Flea Ridden

    Chris Lewis Guest

    Just a bit of a surprise that's all, 10V is not much worse than 9V,
    and tongue-testing 9V batteries is quite popular ;-).

    Imagine, tho, the guy I knew who tongue-tested the charge cap in
    an electronic flash (90V+).

    He couldn't taste anything for a week.
     
    Chris Lewis, Aug 9, 2004
    #94
  15. I as well, but they don't pack the wallop that that adapter did.
    First shop class topic in my firt year EET program.

    Tom
     
    Tom MacIntyre, Aug 9, 2004
    #95
  16. A 9 volt battery can't put out as much current.

    Tom
     
    Tom MacIntyre, Aug 9, 2004
    #96
  17. Flea Ridden

    Chris Lewis Guest

    Enough to be limited by the resistance of your tongue rather than the
    battery, so the short-circuit current limitations aren't really relevant.
     
    Chris Lewis, Aug 11, 2004
    #97
  18. Well...I was there, and have done both, and believe me, the difference
    was relevant...REALLY relevant. :)

    Tom
     
    Tom MacIntyre, Aug 11, 2004
    #98
  19. Flea Ridden

    clifto Guest

    The last time I asked in comp.dcom.telecom, the answer I got was 98V at
    20 Hz (nominal) coming out the office. If all your ringers are electronic,
    there's a good chance you'll see most of that at the phone jack.
    Please cite your FCC spec.
     
    clifto, Aug 12, 2004
    #99
  20. Flea Ridden

    Gary Lecomte Guest

    I use a whole house supressor in my house. Not because it may get
    struck by lightning, but because we get a lot of power losses here.
    With a GOOD Ground on the Main Box and Surpressing the spikes closer
    to the source, definately helps reduce the spikes at the equipment.
    I also have some for sale on my website.

    Take care.......Gary
     
    Gary Lecomte, Aug 15, 2004
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