Neutral/Grounding/Bonding basic question

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Old 12-09-16, 04:12 PM
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Neutral/Grounding/Bonding basic question

I just don't understand ... help me out?

I know that the ONLY place that neutral and ground are SUPPOSED to be connected together, is at the FIRST point of disconnect. At all subsequent sub-panels, the box itself should be bonded with the ground (and possibly another ground rod installed, depending) BUT neutral and ground should NOT be bonded TOGETHER ... they MUST be separate.

OK ............ why?
 
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Old 12-09-16, 05:04 PM
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That question has been answered a few times here at least, but the short version is this: If ground and neutral are bonded in more than one place, there will always be current flowing in the grounds. There should never be current flowing in grounds except in a fault condition, because it makes them a shock hazard under the right conditions and defeats their value as a safety mechanism.
 
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Old 12-09-16, 05:19 PM
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I figured it had probably been answered before, and I did a search but with no luck. Could you point me to one of the more indepth explanations?

I have a mild learning disability and need visuals to understand, if possible
 
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Old 12-09-16, 10:28 PM
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there will always be current flowing in the grounds.
Why will that happen? What is the explanation behind it in terms of Physics?


Note: I know your information is correct regarding how many times and where the N-G should be bonded. But I just wonder why there will always be current flowing in the grounds, I am very interesting to acquire more information and a deeper explanation of why that phenomenon will happen if the Neutral is bonded to Ground in more than one place? And why it doesn't happen when is only bonded at one point? Why???
 
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Old 12-10-16, 04:18 AM
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there will always be current flowing in the grounds.
Why will that happen?
Because there is a parallel path back to the source.

Here is the best picture I could find:

Attachment 74225
 
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Old 12-10-16, 08:57 AM
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Here is the best picture I could find: Attachment 74225
Tolyn, the link to the attachment didn't work. Try it again?
 
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Old 12-10-16, 10:18 AM
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........................ see below
 
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Old 12-10-16, 10:23 AM
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Tying the bare wires and the white wires everywhere fails the single fault safety test. That is, one can describe a single bad connection, and now every metal boxed on a particular circuit is hazardous to touch. Namely, the neutral connection at the load center becomes open. Now, the operating current is mostly headed for the grounding rod, which has quite a few Ohms resistance to ground. Depending on the load, that voltage which is now present on the exposed metal, can become hazardous.
 
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Old 12-10-16, 10:56 AM
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Thumbs up

Understood.

Very well, nice reply!


Thank you.
 
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