Service panel - neutral ad ground bus bars... questions

[67carl]

I have a 200 amp Eaton Cutler/Hammer service panel. A ground bus bar was added - the top bar (pic taken when all the wires were out). All the neutrals are on the original bus bar (bottom bar). I believe that is a neutral bonding ******** the bottom bar. Most of the grounds are on the added bus bar, however there are a few grounds on the neutral bar as well. The two bars are not connected.

I believe because the main disconnect is at the panel you can have neutral and ground on the same bar (just not in the same hole). True?

Do I need to run a bonding wire between the two bars?

 

[nadogail]

I may be mistaken, so everybody should load their FLAME cannons; but in the Main Panel the Neutral and Grounds are bonded together, that is the ground buss and neutral bus are both connected to the can (Panel Enclosure Box).

Downstream Sub Panels the ground bus is isolated from the can, but a conductor is run from the Grounding Bus in the Sub Panel to the Grounding Bus in the Main Panel. I last taught Electrical Wiring during the First Gulf War and those "Code Provisions" may have changed.

 

[wyliesdiesels]

yes in the main panel neutral is bonded to the enclosure and thus any and all EGCs, GECs, plumbing etc

All neutrals should go to the bar with the strap NOT the added bar as code prohibits using the enclosure for the neutral pathway.

1 neutral wire per hole.

yes EGCs can go on either bar.

ground wires can be double up on most panels.

you do not need a wire connecting the 2 bars together.

 

[67carl]

I may be mistaken, so everybody should load their FLAME cannons; but in the Main Panel the Neutral and Grounds are bonded together, that is the ground buss and neutral bus are both connected to the can (Panel Enclosure Box).

Downstream Sub Panels the ground bus is isolated from the can, but a conductor is run from the Grounding Bus in the Sub Panel to the Grounding Bus in the Main Panel. I last taught Electrical Wiring during the First Gulf War and those "Code Provisions" may have changed.

Connected via the screws that mount them to the box?

 

[67carl]

yes in the main panel neutral is bonded to the enclosure and thus any and all EGCs, GECs, plumbing etc

All neutrals should go to the bar with the strap NOT the added bar as code prohibits using the enclosure for the neutral pathway.

1 neutral wire per hole.

yes EGCs can go on either bar.

ground wires can be double up on most panels.

you do not need a wire connecting the 2 bars together.

Then I'm good to go - thanks!

 

[Jim greengo]

Then I'm good to go - thanks!

Put the extra neutrals back on factory installed buss.

 

[Norcal]

One note about doubling conductors in a ground bar, normally they need to be the same size and materiel.

 

[yatg]

Is that a black wire running to the neutral bar? Looks a little small to be reidentified. At least throw a piece of white tape on it.

 

[67carl]

Put the extra neutrals back on factory installed buss.

All the neutrals are on the factory bus with the bonded neutral strap.

Is that a black wire running to the neutral bar? Looks a little small to be reidentified. At least throw a piece of white tape on it.

Thanks for calling that out. That is a mystery wire. I didn't know what it was for, so I didn't touch it. It is a solitary wire (not in an insulated cover with others) that I traced it as far as where it goes into the attic.

An abbreviated background: the previous owner (1 owner house) had a wall mount 240v AC unit installed and they put a 200-amp panel in as well. A few years after I bought the house, I had central HVAC installed. I believe the installers used the same power line from the wall AC for the Central HVAC. It was only relatively recently (few years ago) that I cleaned up and organized the box.

The pic below is how it was/is wired. The AC Unit circuit also has a bare copper wire going to the ground bus bar. So, what could the mystery black wire be? Would a 240v central HVAC need a neutral? Now that I think about it, I do remember the inspection after the initial install failed because the new code required a receptacle be located near the unit. They had to come back and install one, so maybe this is a neutral for that recep, and they grabbed the hot from one of the legs of the 240v near the unit? If so, I do need to put some white tape on it.