Grounding electrode conductor to the neutral buss?

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  #1  
Old 04-30-10, 02:39 PM
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Grounding electrode conductor to the neutral buss?

I have been seearching the archives but have not found an absolute answer to my question, so, a new thread.

I just upgraded the main panel in my house and I also am building a detached garage with a subpanel. I had it inspected yesterday. One note the inspector left says...

"Grounding electrode conductor must attach to neutral buss in panel, not ground buss."

I am assuming he is talking about the main panel and not the sub. At the main panel I have a number 6 copper wire attached to two ground rods, and a number 4 copper wire attached to the water pipe. My question is, are both of these conductors suppose to connect to the neutral bar?

I would ask the inspector but the County works 4 day weeks and therefore are out today. I would like to do the work over the weekend and get it inspected Monday so I can get my power back on ASAP.

TIA,
BWSwede
 
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Old 04-30-10, 04:05 PM
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Originally Posted by BWSwede View Post
My question is, are both of these conductors suppose to connect to the neutral bar?
Yes. He is correct. In the main panel the grounds and neutrals are connected together. The "can" (the metal part of the panel) should also be bonded to the neutral buss via the main bonding jumper. This will either be a large green screw going through neutral bar and into the metal can or a strap attached to the neutral bar with a screw attached to the can.
 
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Old 04-30-10, 04:42 PM
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Tolyn,

Thank you for the reply. I understand the ground and the neutrals are connected together in the main panel and separated in the sub panel. (I have the green screw installed to bond the neutral buss to the can.) With this in mind, what I can't understand is whether he wants me to move both the ground rod and water pipe conductors from the ground buss to the neutral buss, and if so why if they are all connected in this panel anyway. Do you know why?

Thanks again,
BWSwede
 
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Old 04-30-10, 05:15 PM
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Originally Posted by BWSwede View Post
Tolyn,

Thank you for the reply. I understand the ground and the neutrals are connected together in the main panel and separated in the sub panel. (I have the green screw installed to bond the neutral buss to the can.) With this in mind, what I can't understand is whether he wants me to move both the ground rod and water pipe conductors from the ground buss to the neutral buss, and if so why if they are all connected in this panel anyway. Do you know why?

Thanks again,
BWSwede
Your inspector is misreading the code. 250.24 specifies that if the main bonding jumper is a wire or bus bar and is bonded to the grounding bus, you may attach your grounding electrode conductor to the neutral bus. There is no requirement to do so, and if you wanted to be picky since the main bonding jumper is a screw you have no exception that allows the GEC to be connected to the neutral bus. Technically you are required to put the GEC on the grounding bus, so you did everything to the exact letter of the code.

Functionally, there is no difference and he wants it that way, so your best solution is to take five minutes and move the wires.

EDIT: and yes, he is talking about the main and not the sub. In no way are the ground and neutral to be mixed in the sub panel. Isolate them completely.
 
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Old 05-01-10, 11:14 AM
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I agree with RHefferan. I'm not sure why he's being that picky unless he mistook the main panel for a sub panel.
 
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Old 05-01-10, 11:59 AM
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There is a "fine point" in Art. 250.24 , (A), (4),which may apply to your installation and the inspectors NEC interpretation. It reads ----

"Main Bonding Jumper as Wire or Busbar.---- Where the Main Bonding Jumper is a wire or busbar , and is installed from the Grounded Conductor terminal bar to the Equiptment Grounding terminal bar in the Service equiptment , the Grounding Electrode Conductor shall be permited to be connected to the Equiptment Grounding terminal bar."

This brings into question the design of the Service panel. Your panel may have a factory-installed busbar linking the Neutral ( "Grounded Conductor" ) terminal bar to the Equiptment Grounding terminal bar , which is factory Bonded to the metallic surface of the Service enclosure.

(B) , Main Bonding Jumper --- " A Main Bonding Jumper shall ( connect together ) the Equiptment Grounding Conductors , the Service dis-connect enclosure , and the Grounded (Service) Conductor___"
 
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Old 05-01-10, 08:23 PM
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Thanks again guys for your responses.

Tolyn, There is no way he mistook the main panel for the sub. The sub is in the garage about 50' away.

Pattbaa, You lost me...The panel is a new Square D Homeline series. Does that tell you anything?

In the end, I guess I'll just do what he says and move the conductor from the ground rod and the conductor from the water pipe to the neutral bar, even though I don't understand why.

Thank you,
BWSwede
 
  #8  
Old 05-02-10, 04:52 AM
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Originally Posted by BWSwede View Post
(I have the green screw installed to bond the neutral buss to the can.)
this is the case only in the main panel, correct?
 
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Old 05-02-10, 10:34 AM
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this is the case only in the main panel, correct?
Yes. The sub panel is a Siemens and is the type that has a thick removable wire between the neutral buss and the ground buss. This wire has been removed.

Thanks,
BWSwede
 
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Old 05-02-10, 12:38 PM
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"Main Bonding Jumper as Wire or Busbar.---- Where the Main Bonding Jumper is a wire or busbar , and is installed from the Grounded Conductor terminal bar to the Equiptment Grounding terminal bar in the Service equiptment , the Grounding Electrode Conductor shall be permited to be connected to the Equiptment Grounding terminal bar."

"Your panel may have a factory-installed busbar linking the Neutral ( "Grounded Conductor" ) terminal bar to the Equiptment Grounding terminal bar , which is factory Bonded to the metallic surface of the Service enclosure."

***************************************************

The terminal bar where the "Neutral' Service Conductor terminates is the "Grounded Conductor terminal bar "--- the White conductors of the cables that extend from the panel connect to this bar.IF- IF- there is a "strap" , AKA a "Busbar" , between the Grounded Conductor terminal bar and another terminal bar , that "other" bar is for terminating the bare Grounding Conductors of non-metallic cables . It's possible this strap / busbar link between the two terminal bars is concealed.

You need to examine the panel for this connection. If you purchased the panel from an electric supply store , they can inform you as to the exact design of the panel.
 
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