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Thread: I'm seeing Mike's battle

  1. #21
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    Going through this since I became an electrician was always a battle.

    Sometime in the eighties, I finally got the wording so I knew when the code said, "grounding" and sometimes said "Grounded", I had it down. Then, somewhere they changed those meanings to now something that is not exactly the same as then.

    The industry looks like its finally got their act together and defined the terms better. Now, if they would just stick to them I wouldn't have to relearn this stuff all over...

    Once we figured out those grounds rods in the back yard at the service were for lightning strikes and not tripping breakers, the rest got easier real fast...

  2. #22
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    Quote Originally Posted by gadfly56 View Post
    So, by your explanation, if I had no electric service to my house of any kind, I'd still have to ground the rebar in my foundation?
    Electrical service is not necessarily relevant to the need for a ground. It's the existence of anything that can build up a charge in isolation to ground, or in isolation from other such devices. If we have wires and motors and an assortment of other like devices in our house...then yes, they can build up charges even with no electrical service to the house.

    It can come from lightning, or even from the presence of a charged cloud over your house. A positive charged cloud over your house, will induce a negative charged "mirror" image of charges on the ground below. Lightning is what occurs when the air gap threshold between cloud and ground is exceeded. A strike attempts to equalize charges. If the air gap threshold isn't exceeded...no lightning occurs...but the charge build up is there...or moves along with the cloud. And lightning between clouds establish magnetic fields that couples with things in the house

    Some belt driven motors can create substantial static build up...enough for a resulting spark to start a fire.

    Charges are all around us. We only notice their existence when something happens. That bite of static discharge between hand and door knob. The crackle of static as we pull apart socks fresh from the dryer. And yes...that smack of lightning during a thunder storm.

    Basically, we want to make sure that anything in our house that can build up charges has a way to discharge those charges in an orderly manner. Bounding all this stuff together, and then making a connection with ground, goes a long way to achieving the goal.

  3. #23
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    More than grounding and bonding in a building, certain objects such as lamp posts may require additional protection of bonding: suppose a person is in touch with a metal lamp post, properly grounded, when the phase conductor shorts to lamp post. The person would be subject to a shock voltage for a duration till the associated protective device cuts off supply to lamp post. This could be dangerous. So in such condition it may be prudent to provide a small earth mat bonded to lamp post.

  4. #24
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    Quote Originally Posted by Sahib View Post
    So in such condition it may be prudent to provide a small earth mat bonded to lamp post.
    Is this ever done?
    Dave Ruth

  5. #25
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    Quote Originally Posted by readydave8 View Post
    Is this ever done?
    Seen it done with pole operated switches where the lever is meant for ground level switching. Also seen it done in substations.
    I'm in over my head...

  6. #26
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    Quote Originally Posted by mbrooke View Post
    Seen it done with pole operated switches where the lever is meant for ground level switching. Also seen it done in substations.
    And if implemented incorrectly it can actually increase the risk oof step potential injury.

    Sent from my XT1585 using Tapatalk

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