Where to ground my sub panel

[hutchijw]

I have just put in a sub panel. It's a Siemens panel. See pics below. My main breaker is a Square D panel (the box with corrosion on it). Here's my question. I have 2 hots, a neutral (black w/blue strip) and a ground. When I run this 4 wire cable to my main breaker, the grounds and neutrals are on the same bar. Where should I connect the ground comming from my Siemens box into my main panel? I thought maybe to where the ground comes in from the pole but that would involve calling the power company right?

[hutchijw]

http://www.hammerzone.com/archives/elect/panel/sub_panel/01/overview.htm

According to this, I can connect it to the neutral/ground bars and it will be ok. Thoughts/suggestions?

[Macrosill]

hutch,
The grounds and neutrals terminate at the same location in a main panel. All the neutral bars are bonded together. It looks like you might have to buy some lugs to fit the conductors going to the subpanel.

From the pics it looks like you properly installed the subpanel by isolating the neutrals from the grounds.

[Jeff Millard]

hutch,
The grounds and neutrals terminate at the same location in a main panel. All the neutral bars are bonded together. It looks like you might have to buy some lugs to fit the conductors going to the subpanel.

From the pics it looks like you properly installed the subpanel by isolating the neutrals from the grounds.

I highlighted Brian's response in a place I wanted to add emphasis. The Neutral and Ground are only bonded to the same location in the Main panel. They need to be isolated from each other in any sub panels. You have done this properly in your construction.

Just a suggestion... When you go to make your connections, you should pull the meter to ensure nothing is hot (this might require a call to the utility to get a troubleman to open the barrel lock on the meter) You can say you are making repairs (the next thing I am going to point out is your excuse) Then get some NOLOX, and wirebrush and coat your Neutral and Ground connections in your main panel. That corrosion is due to dissimilar metals clamped together without an Oxygen barrier. It will result in extreme heat, and could cause the connection to ignite the insulation of the wire.

Please, as always, be careful... and test before you touch...

Jeff

[hutchijw]

I've added a picture as to what I think is a lug (please confirm). From the notes above, I will be buying 2 of these lugs and add them to my neutral/ground bars located in my main breaker. I'll put 1 lug on the right bar and the other lug on the left bar.

[Macrosill]

hutch,
The grounds and neutrals terminate at the same location in a main panel. All the neutral bars are bonded together. It looks like you might have to buy some lugs to fit the conductors going to the subpanel.

From the pics it looks like you properly installed the subpanel by isolating the neutrals from the grounds.

I highlighted Brian's response in a place I wanted to add emphasis. The Neutral and Ground are only bonded to the same location in the Main panel. They need to be isolated from each other in any sub panels. You have done this properly in your construction.

Just a suggestion... When you go to make your connections, you should pull the meter to ensure nothing is hot (this might require a call to the utility to get a troubleman to open the barrel lock on the meter) You can say you are making repairs (the next thing I am going to point out is your excuse) Then get some NOLOX, and wirebrush and coat your Neutral and Ground connections in your main panel. That corrosion is due to dissimilar metals clamped together without an Oxygen barrier. It will result in extreme heat, and could cause the connection to ignite the insulation of the wire.

Please, as always, be careful... and test before you touch...

Jeff

I concur captain! Everything Jeff said is 100% accurate.

[Macrosill]

I've added a picture as to what I think is a lug (please confirm). From the notes above, I will be buying 2 of these lugs and add them to my neutral/ground bars located in my main breaker. I'll put 1 lug on the right bar and the other lug on the left bar.

Yup, thats a "lug"

[Photovor]

Don't forget too, usually from the bottom of one of your ground buss bars, take at least an 8AWG copper wire (un insulated) run it through one of the very small knockouts in the bottom of your panel (they're like the side of a small hole punch) and clamp that to the closest copper incoming cold water pipe.

In commercial panels, this would go outside to a ground bar driven in the ground about 4'.
This further acts as a ground in case you would lose the ground or neutral that goes out to your meter socket.

[Jeff Millard]

Don't forget too, usually from the bottom of one of your ground buss bars, take at least an 8AWG copper wire (un insulated) run it through one of the very small knockouts in the bottom of your panel (they're like the side of a small hole punch) and clamp that to the closest copper incoming cold water pipe.

In commercial panels, this would go outside to a ground bar driven in the ground about 4'.
This further acts as a ground in case you would lose the ground or neutral that goes out to your meter socket.

A very good point! Bonding to the copper is part of the code, and not only will it act as a ground if damage occurs to the bonding of the normal driven ground(S) (two are required in most cases now, spaced approximately 6' apart) It will also ensure that there is no difference of potential between the copper and the electrical circuits of your home. Earth can become energized in one location and not in another, causing a potential between two grounded conductors (on one hand the copper coming into the house, and the other being the driven grounds) If they aren't bonded together, the possibility exists for deadly voltage. Follow the code! It is meant to save lives and promote proper electrical construction .

Edit: One thing I might have missed here is the possibility that it is being suggested to ground from the sub-panel to the copper water pipe. This is fine but not a requirement by code. The water pipe bonding to the main panel is mandatory. Jeff's rules say that overkill is good, yet copper is expensive (thank you for the copper, gas and concrete prices Mr. Bush) so it is a judgement/cost analysis issue...

Jeff

BTW, the code specifies the actual gauge of the solid bare copper wire that is required for this bonding application. 6AWG was required when I installed my 200amp panel. A licensed electrician should be able to help you with the actual requirements of your electrical service.