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Lightning rod missing on building

Discussion in 'Electrical Engineering' started by Skybuck Flying, Jun 6, 2011.

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  1. Don Kelly

    Don Kelly Guest

    "Androcles" wrote in message

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    |
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    | "Androcles" wrote in message |
    |
    | | On Jun 20, 9:15 am, "Androcles" <.
    | 2011> wrote:
    | >
    | > | > On Jun 20, 12:18 am, "Androcles" <.
    | >
    | >
    | >
    | > 2011> wrote:
    | > > Taking into account that bathwater electrocutions were unheard of
    | > > prior to Edison's electric chair...
    | -----
    | and prior to that time, the only electrical device most people had was a
    | light bulb. Some had motors but there was no need for these in a bathroom
    or
    | kitchen.
    | --------------
    | > > Taking into account that early plumbing was piped with Pb and
    therefore
    | > > a good ground...
    | > > Taking into account that early bath tubs were vitreous coated
    | > > cast-iron...
    | ----------
    | And the drain was bare metal- connected to the plumbing which was likely
    to
    | be cast iron or even copper- ground path existed.
    | ----------------
    | > > Taking into account that a measly 120V AC is the source of energy...
    | --------------
    | and has done in many- I had to deal with a situation- it appeared that the
    | victim touched a toaster and a refrigerator (with no safety ground) at the
    | same time.

    Ah, but with a wacky centre-tap system the toaster and fridge could have
    been on opposite phases, doling out 240V.
    ---------------------
    I don't recall all the measurements that I took at the time (about 30 years
    ago) except that the toaster checked out well. It's external metal parts
    were either grounded properly or well insulated from any live parts. The
    problem you suggest is a possibility but the reason that possibility could
    occur is the old non-polarized plugs and no safety ground. I have no
    recollection of this being the case. I vaguely recall measuring a low
    voltage on the fridge and looked for this as I have had some personal
    experience with that happening (in my case, just an annoying tingle on
    touching the handle-- no problem- but a reversed plug (2 prong, unpolarized)
    plus some insulation leakage appeared to be the case. Looking back, it may
    have been someone trying to cover their ass legally and the guy died of an
    unassociated heart attack.

    As for the electrocution in a tub- it has happened- whether or not it was
    due to wet skin on a salty bag of guts providing a path parallel to the
    water or due to a reaction by the tubbee and direct contact to a grounded
    tap, or to grabbing the heater or radio and lifting it out of the tub,
    making oneself the main part of the path from device to water to ground- I
    have no data on this.

    Don Kelly
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  2. Don Kelly

    Don Kelly Guest

    "Androcles" wrote in message

    | "Androcles" wrote in message |
    |
    | ||
    ||
    ||
    ||
    || "Androcles" wrote in message ||
    ||
    || || On Jun 20, 9:15 am, "Androcles" <.
    || 2011> wrote:
    || >
    || >
    || > On Jun 20, 12:18 am, "Androcles" <.

    | ---------------------
    | I don't recall all the measurements that I took at the time (about 30
    years
    | ago) except that the toaster checked out well. It's external metal parts
    | were either grounded properly or well insulated from any live parts. The
    | problem you suggest is a possibility but the reason that possibility could
    | occur is the old non-polarized plugs and no safety ground. I have no
    | recollection of this being the case. I vaguely recall measuring a low
    | voltage on the fridge and looked for this as I have had some personal
    | experience with that happening (in my case, just an annoying tingle on
    | touching the handle-- no problem- but a reversed plug (2 prong,
    unpolarized)
    | plus some insulation leakage appeared to be the case. Looking back, it
    may
    | have been someone trying to cover their ass legally and the guy died of an
    | unassociated heart attack.
    |
    | As for the electrocution in a tub- it has happened- whether or not it was
    | due to wet skin on a salty bag of guts providing a path parallel to the
    | water or due to a reaction by the tubbee and direct contact to a grounded
    | tap, or to grabbing the heater or radio and lifting it out of the tub,
    | making oneself the main part of the path from device to water to ground- I
    | have no data on this.
    |
    So if your better half wants to collect the insurance on you by dropping
    the hair dryer into your bathwater I recommend that you stand carefully
    without touching anything that might be grounded, leave the hair dryer
    to propel itself through the water from its reaction with the jet of water
    it will be emitting from its heater, and step out onto the insulated rug.
    With a dry towel grasp the plug and pull it from the socket. Next visit
    the breaker box, disconnect the supply, return to the bathroom with
    a packet of blu-tack and stuff the gunk into socket, thereby preventing
    any further use of a replacement hair dryer except in another location.
    Next, towel off and get dressed.
    If this event has not yet happened, I still recommend the blu-tack in
    the socket until such times as the socket is removed and the wall
    replastered... unless of course you are planning on collecting the
    insurance on your better half, in which case always lock the bathroom
    door should you need to bathe.
    --------------------------------
    Nah- I'll ignore your advice as:

    a) note that I have modern wiring which is up to code and provides for
    Ground fault protection in the single bathroom outlet.

    b)have forced air heating.

    c)avoid doing asinine things with electrical apparatus- what should be is
    not always what will be.

    d)recognize that "one can make things foolproof but not damnfool proof".
    (citing Dr. Harle, a long gone EE prof from England who did a good job of
    mixing the theoretical and the practical)

    e)etc. :)

    f)this topic has been beaten to death.

    Don Kelly
    cross out to reply
     
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