romex jockey101
Member
why is the nuetral and the grounding conductors bonded at the main panel is that what makes it a nuetral that its bonded to the grounding
bonding
- Thread starter romex jockey101
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A phase to ground fault needs a path back to the source to operate the OCP device. The grounding to neutral provides that path.
A "neutral" is established by the sourece (common-point of a wye, mid point of a single phase, etc.)
A "neutral" is established by the sourece (common-point of a wye, mid point of a single phase, etc.)
romex jockey101
Member
thank you.so its bonded at the main panel so if ever a hot touches a grounded condutor[nuetral] it will give it a path to ground and trip the breaker.....
Ground has nothing to do with tripping the breaker, the EGC creates low impedance path back to the source.
Roger
somewhat,.... if the phase (hot) conductor touched the neutral directly it would form its own path (regardless of bonding). The bond is there to provide a path between the grounding conductor (or items that are grounded) to the neutral or the service enclosure and the neutral.
romex jockey101
Member
so the grounded conductor and gounding conductor are bonded so that the unbalced load will find its way back to the panel and leave through the sec nuetral....
- Occupation
- Licensed Electrician
This graphic may be confusing in the context of the OP because it shows a meter reading 120V to earth instead of the guy with his hair standing on end, getting shocked.
romex jockey101
Member
so the bonding of the nuetral and gounding at service discoonect allows a path for the load on the nuetral to come back to the panel..
jumper
Senior Member
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- 3 Hr 2 Min from Winged Horses
obviously something is (confusing)...
I gave up
The problem is that the OP is intertwining 3 different questions:
1.What is the purpose of a EGC?
2.What is the purpose of a GEC/GES or why do we connect the neutral to mother earth?
3. Why is the GES established at the first means of disconnect?
- Occupation
- Licensed Electrician
Then this link would be helpful.http://forums.mikeholt.com/showthread.php/95495-Grounding-amp-Bonding-The-Big-Picture-Post?p=748232#post748232
Rick Christopherson
Senior Member
That's a very nice writeup that George Stolz wrote, but it is subtitled, "The Big Picture", when in fact it should be subtitled "Mike Holtz' Picture". While Mike is very well respected, that doesn't automatically mean that everything he states is considered gospel across the whole industry. Mike's teachings have dispelled some misconceptions, but they have also created some as well.
romex jockey101
Member
i understand egc is so if a hot[ungrounded condutor] touches a metal object it wont stay energized and use a human as a path to ground so we bond it to the egc so when a hot hit the meatl object it will flow through the egc and trip the breacker. the gec. grounds the system and gives us a path to ground for the egc...im tryn to understand y the nuetral is bonded to the grounding condutor...i understand y in a sub panel u keep them seperate bc you dont want current running through the nuetral in case of a ground fault...but i will read up on it so i gain the knowledge
skeshesh
Senior Member
- Location
- Los Angeles, Ca
Think about this: what would happen if you don't bond the neutral at the ground? What makes a phase conductor "hot"?
Voltage is a potential difference that is established between two points. In a typical light commercial North American LV system, you have 208 volts between phase conductors. When you ground a neutral, the grounded conductor is at 0 potential so that you establish a phase to neutral voltage of 120V. You are asking the right kind of questions, do the research on your own but do post concerns if you don't understand something and the good people of the forum who I've learned plenty from will be sure to lend a hand.
Voltage is a potential difference that is established between two points. In a typical light commercial North American LV system, you have 208 volts between phase conductors. When you ground a neutral, the grounded conductor is at 0 potential so that you establish a phase to neutral voltage of 120V. You are asking the right kind of questions, do the research on your own but do post concerns if you don't understand something and the good people of the forum who I've learned plenty from will be sure to lend a hand.
romex jockey101
Member
ok that makes sense thank u for ure time
tryinghard
Senior Member
- Location
- California
Always remember electricity is not seeking ground it is seeking its source. You can have a fault (hot to metal) and if the metal path back to the specific source is bad the circuit will not trip. Correct equipment grounding includes an effective fault current path anything less is not correct and hazardous, read 250.4(A)(3)-(5).
You?re close though this same short will only travel back to the source effectively if the bonding is at the service disconnect area because it needs the services neutral to be effective.
If the bond is not in place it would only be luck at best to trip the circuit because this same short would be relying on the earth between the source transformer and the service disconnects electrode; 4.8A would occur if there were 25 ohms (between the transformer?s GEC and service disconnects GEC) at 120V ? you would need less than 8 ohms for a 15A circuit to trip. The earth?s resistance is unknown at any given moment this is why it is extremely hazardous and a code violation to use as a fault path, think of it as not possible and this is the best mindset.
SG-1
Senior Member
- Location
- Ware Shoals, South Carolina
Have you watched the power point presentation posted in "The Big Picture Post" in the Grounding vs Bonding Forum ?
http://www.tirebiter.net/downloads/ludecke.html
http://www.tirebiter.net/downloads/ludecke.html
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