Pos and Neg Battery switching

Discussion in 'Electrical Systems' started by Frosty, Jul 9, 2011.

  1. Frosty

    Frosty Previous Member

    Right--- if it is induction then I have nothing to worry about but the AC feed cable is about 1 meter from the engine but does pass the Morse cables (good call there).

    The marina Earth sucks which is why a boat on d dock lost his prop and I will not be connecting to it-- fit a third wire to a bonding system and I will be an earth for everyone else. That would be a crazy thing to do, Ok in US,-- but Im not there.

    The batt charger is a master volt and is screwed under the steering station fastened to a wood panel, it is connected in to the bus bar it works fine.

    The sole is carpeted and wood in the galley, it would be impossible to get a good belt and In any case the boat cant ground either so how can it generate an earth track to belt me.

    As an apprentice I used to know a big Irash man that would get hold of a spark plug wire and hold it, he would grab hold of people as they passed by. This shock reached you elbow but when electronic ignition came out it would reach you arm pit and it was easy to tell the voltage of each system. The big dumb Irish bloke would arc the spark from various parts of his body as he would jump and twitch to each fire.

    As I see it the only way I could get a belt would be carpet the boat in ally foil attached to the neutral AC !!!! It cant flow through me if it cant get out and that is the trick of the frosties guide to wiring. Making a third wire bonding increases the potential of finding a path. There is none so no shock.


    Yes I am in a crowded marina and I think this is also a good call but I don't see what I can do about that . I use anodes at a rate I feel is appropriate.

    I always drain and flush main engines with fresh water and leave dry I do not corrode the engine pencil anodes.

    Would AC induction go the the batt if I left the neg sw on.
     
  2. bntii
    Joined: Jun 2006
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    Location: MD

    bntii Senior Member

    In a past life I pulled wiring in new houses- it was a standard ploy to lick a finger and tap a bare wire to see if the circuit was hot.
    It was easy to feel the diff of 110 and 220 by the amplitude of the 'tingle' :p

    Some years later and a few accidental hits from live wires and I find myself a bit gun shy- to my mind it seems a bit too fancy to suppose you are getting a charged engine/shaft system from induction- especially while the whole bit is grounded to the water... Take the least risk route and assume the worse: look for a stray current making the gear live.
     
  3. thudpucker
    Joined: Jul 2007
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    Location: Al.

    thudpucker Senior Member

    From what I recall, electrolysis is not strong enough to discharge your battery if the Pos cable is open at a Knife switch.
    Induction, if its strong enough (You'd be hearing a buzzing noise) can discharge a battery that is not even connected to anything.
     
  4. Frosty

    Frosty Previous Member

    Your concerned about me getting a shock and Bnti lick his fingers and flicks the hot wire. Thats because you prob had big boots on.

    So,-- shore power unplugged,-- batts off, no tingle! eh? Ille try it.

    I like that induction thing very much I think thats a winner.

    Im not saying it will flatten the batt --I am saying will the batt absorb the induction if I leave the Neg switch ON ( its not a knife Sw) Its a rotation 1-2 off and same Pos.
     
  5. bntii
    Joined: Jun 2006
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    Location: MD

    bntii Senior Member

    Na- just standing in a dry wood frame house.
    I did once have the poor sense to reach into a sump pump well to extract a failed pump while standing in half a foot of water....

    The big boots probably saved me. The water felt like it was covered with fur- quite a shock- literally.
     
  6. thudpucker
    Joined: Jul 2007
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    Location: Al.

    thudpucker Senior Member

    NO! With a battery, only some hi power induction will discharge it if one or both poles are detached.

    PS: as a kid working for a Roofer, I've watched some Electricians pull some pretty aggrevating stunts.
    I wear Rubber gloves to turn on the lights:D
     
  7. SheetWise
    Joined: Jul 2004
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    Location: Phoenix

    SheetWise All Beach -- No Water.

    And if you look, you can find them for $5 per 100 -- no reason not to.
     
  8. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    why not hook up to the marina ground using a galvanic isolator

    http://www.yandina.com/galvanicIsolator.htm

    the USA, ELCI type of device which is an expensive but good idea, is only required for brand new boats. old ones just a suggestion.
    I do not have one on my twin 30 amp shore line., just breakers. All outlets are wired threw a GFCI.
     

  9. aswin

    aswin Previous Member

    hi thanks for your information i am new to this forum
     
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