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-   -   To bond or not to bond,That is the question (http://www.diychatroom.com/f18/bond-not-bond-question-462/)

generaltzao 03-23-2005 01:22 PM

To bond or not to bond,That is the question
 
External building (Shed), with NO water supply or pipes going to main building, 120/240VAC 60A Underground service, 115 feet away from main. 8' Copper Electrode at BOTH buildings. In THIS case I would think A BONDING to the N-Bus to be correct as the Main house is far away and no pipes connect the two. So a ground to the house would not be preferred by electricity over the local ground rod. Furthermore, Any Electricity or faults from the House (MAIN) would prefer to go to the Main's Local grounding rod and water pipes over traveling all the way to the Sheds Ground rod. At all time keeping the ground INSIDE the underground conduit NON-Charged, as well as any service ground remaining UN-Charged such as phone and appliances.

Now If there were pipes connecting the 2 buildings then the N-Bus would NOT be bonded as a fault could prefer the Pipes ground over the Rods grounds, traveling through the non-Fused water pipes looking for the First Ground which may result in being the plumber. http://www.diyrepair.com/forums/images/smilies/eek.gif

If I were installing a sub-panel IN the House I would NOT bond as a fault might travel through the ground wire or the Neutral and cause a possible shock or a 240V load to the 120V circuits risking a fire. Do I have it right?. Or am I still way off? http://www.diyrepair.com/forums/imag...s/confused.gif
__________________________________________________ __
NEC code rule#1) If it is easier.. its wrong.
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jbfan 03-23-2005 05:22 PM

IMO a subpanel in a seperate building, do not connect the N_G together. Are you feeding with a 4 wire feed?

Speedy Petey 03-26-2005 09:40 AM

You are generally correct. The only thing is the purpose of a ground rod, or the ground itself is not to clear a fault. It is to stabilize the electrical system in the event of a very short term high current fault such as lightning.
Grounding and grounding electrode systems can be an extremely confusing subject.

Bottom line is if you ran a 4-wire feeder to the out building then the neutrals and grounds are NOT bonded in the sub-panel.
If there are not other metallic paths between bulidings and if there is a 3-wire feeder then they DO get bonded.
This is regardless of any ground rods, they are required at each building in ANY case.


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