Ground screw question

[Youngfd]

I just finished running power from my house to my small cabin. 30 AMP feed from house to a SQUARE D 100 AMP box in cabin. 8 gauge wire. Question. I have a box bonding screw left over. Do I need to use it? I do have a ground rod outside with a ground wire run into box. Thanks, Jim

 

[Dagny]

8ga cu. 40 amp wire. you need to separate your grounds and neutrals also.

 

[wyliesdiesels]

Did u run a 3-wire or 4-wire feed?

Looks like 4-wire which is required.

If 4-wire, then u dont need the bonding screw and u will need to get a sq d ground bar kit and move any EGCs/grounds over to the new bar.

What size wire did u run?

 

[zmaxmotorsports]

Did u run a 3-wire or 4-wire feed?

Looks like 4-wire which is required.

If 4-wire, then u dont need the bonding screw and u will need to get a sq d ground bar kit and move any EGCs/grounds over to the new bar.

What size wire did u run?

 

[checkthisout]

I just finished running power from my house to my small cabin. 30 AMP feed from house to a SQUARE D 100 AMP box in cabin. 8 gauge wire. Question. I have a box bonding screw left over. Do I need to use it? I do have a ground rod outside with a ground wire run into box. Thanks, Jim

1)The answer is NO, you will not use it in your application.

2)Then, as Wileys stated: You need to install another bus bar in your panel just like the one your neutrals (whites) and grounds (bare copper wires) are connected to now. They make kits for this.

You will then move your ground wires (the bare copper ones) off of that bar and onto the new bar.




Ok, so why? The green screw you have is used to electrically connect the current metal bus bar holding the grounds and neutrals to the metal in the box. Since you will be using the current bar for the neutrals only, and since your application requires separation of the grounds (bare copper wires) and the neutrals (the white ones), you can throw the screw away. Your grounding bar kit that you will moving the ground wires to, will need to be electrically connected the metal in the panel. This will (should) be accomplished with the screws it comes with.

 

[wyliesdiesels]

To further explain, u dont want a bonded neutral bar in a subpanel because u could have neutral return current flowing on grounded metal pathways which would create a shock potential.

 

[LS6 Tommy]

Aren't you supposed to have (2) ground rods, too? We put them in when I upgraded my service.

Tommy

 

[theoldwizard1]

Aren't you supposed to have (2) ground rods, too? We put them in when I upgraded my service.

In theory you can use 1 but only if the inspector has the proper testing equipment to approve it. 2 is the guaranteed-to-pass way to go.

 

[wyliesdiesels]

Aren't you supposed to have (2) ground rods, too? We put them in when I upgraded my service.

Tommy

In theory you can use 1 but only if the inspector has the proper testing equipment to approve it. 2 is the guaranteed-to-pass way to go.

Inspectors dont test ground rod impedance.

It is upto the installer to PROVE to the inspector that there is 25ohms or less impedance with one rod. Otherwise, 2 are required!

 

[Youngfd]

Thanks for all the help. Picked up the ground bar kit and pulled all the grounds off of the neutral bar.

 

[Slowgsr]

You could have just twisted one around a screw and connected them all with a wire nut - ground bar method is much better.

Do you have a local disconnect that isn't shown in the cabin?

 

[checkthisout]

You could have just twisted one around a screw and connected them all with a wire nut - ground bar method is much better.

Do you have a local disconnect that isn't shown in the cabin?

He's got less than 6 in the panel.

 

[zmaxmotorsports]

He's got less than 6 in the panel.

Its still nice to have a single disconnect when youre that far from the power source in my book anyway.
Of course mt book is old and missing some pages.

 

[checkthisout]

Its still nice to have a single disconnect when youre that far from the power source in my book anyway.
Of course mt book is old and missing some pages.

Yeah, but you know...$$$$$ and more time.