How To Connect Sub-Panel Ground Wire At Meter Breaker

[JD5210]

I want to upgrade the wiring that is in my shed from 60amp to 100amp and bring it up to code. The meter is on a pole 20 feet away from the shed with a 200amp breaker box under it. The 200amp breaker box has 2 120 lines and a neutral. As I understand it I will need to install a sub-panel in the shed. Run a 2 gauge 4 wire from the sub-panel to the 200amp breaker.

My question is at the breaker box on the pole. I know where to connect the 2 -120 lines and the neutral. How do I connect the ground wire from the shed? Do I just put in a ground pole under the 200amp breaker and run the ground wire down to it in a metal pipe? Or do something else?

Thanks in advance for any help.

 

[JPRambo]

The Main Panel at the meter has a grounding wire that goes to a driven ground rod, correct? If so the ground wire at the MAIN PANEL (for the sub panel) is connected to the same place as the neutral and ground wire. Now, in the sub panel you need a separate ground bar for the ground and the grounds for the branch circuits (lighting and receptacle, etc.. The sub panel will likely come with a long green screw (to be inserted thru the neutral bar if not used as a sub panel) for the sub panel throw the screw away, do not use it.

 

[JD5210]

The 200amp breaker box and the meter was put in at least 40 years ago and there is no ground pole under the 200amp breaker and why I ask the question. The breaker box that is currently in shed only has 2 - 120 and a neutral and why I want to bring it up to code.

Thanks for confirming for me that in the sub-panel NOT to bond the ground and neutral together.

 

[TCJatko]

"Thanks for confirming for me that in the sub-panel NOT to bond the ground and neutral together." Can someone explain why this is not acceptable practice? The grounding wire is connected to the neutral at the service entrance, and connected to the housing,as are the grounds. At the sub-panel, the neutral wires go directly through the wiring back to the service entrance, and are bonded to the box along with the grounds. Why not connect grounds to the box at the sub panel?

 

[heviduty]

If you connect neutral and equipment grounding conductors together at both ends, you have parallel current paths, and therefore, current in both conductors. Current in a wire causes a voltage drop, so the ground and all metal connected to it in your shed could potentially be at some voltage above ground, depending on the amps drawn. Also, if the neutral connection in your main panel works loose or deteriorates, anything connected to the ground in the shed could be at line potential. The equipment ground (grounding conductor) must always be at ground potential, as opposed to the neutral (grounded conductor). It is for your safety.

 

[TCJatko]

If you connect neutral and equipment grounding conductors together at both ends, you have parallel current paths, and therefore, current in both conductors. Current in a wire causes a voltage drop, so the ground and all metal connected to it in your shed could potentially be at some voltage above ground, depending on the amps drawn. Also, if the neutral connection in your main panel works loose or deteriorates, anything connected to the ground in the shed could be at line potential. The equipment ground (grounding conductor) must always be at ground potential, as opposed to the neutral (grounded conductor). It is for your safety.

I see that possibly, under extreme conditions, the grounding circuit might be at some potential above ground. To solve this, a ground rod at the sub-panel, hooked to the grounding circuit and the surrounding box would certainly do the trick, right? Then the connection between neutral bar and ground bar would be OK?

 

[heviduty]

To solve this, a ground rod at the sub-panel, hooked to the grounding circuit and the surrounding box would certainly do the trick, right? Then the connection between neutral bar and ground bar would be OK? .

No, because then you would have 3 parallel current paths. You isolate your neutral bus at the sub-panel. The neutral conductor, white wire, carries unbalanced current from the 120 volt phase wires. The grounding conductor, green or bare wire, keeps everything you come in contact with at ground potential. It can only do this if it does not normally carry current. Adding a ground rod at the shed panel is fine, just connect it to the grounding, green or bare, conductor. You can't have too many grounding electrodes. The important thing is that the neutral and grounding conductors only get connected together at the main panel.

 

[JD5210]

Heviduty thanks for the responses. Not sure I got my questioned answered, but I will plan to add a ground round at the pole that has the meter and 200amp breaker, doing this way will keep me far enough away from the ground rods for my electric fence charge.

Sorry to those that read this post as it got a little confusing with other people jumping into the post with other questions instead of starting a new thread.

 

[GregbkH]

Do not bond the ground and neutral together at the sub-panel. You want only one good path to ground back to the main panel. Multiple paths (parallel) will take longer to trip the breaker during a fault. You want to clear the fault as quickly as possible. It could save your life.

 

[TCJatko]

Do not bond the ground and neutral together at the sub-panel. You want only one good path to ground back to the main panel. Multiple paths (parallel) will take longer to trip the breaker during a fault. You want to clear the fault as quickly as possible. It could save your life.

With apologies to the OP for highjacking the thread ( I thought my questions were relevant and even educational), the above statement makes no sense to me. The circuit protection device (breaker) is located on the supply (high) side. Numerous parallel paths to ground are irrelevant. If the current exceeds the capacity of the breaker, it opens (hopefully). If not, it doesn't. Unless you are dealing with GFCIs, which are a different ball of wax.