Just to be sure, before I call it a defect, there is no way the neutrals and grounds really are separate on this Sub Panel, correct?
Not the way they are supposed to be. They did a neat job “separating” them but they are on the same buss bar, so they are connected.
That green bonding screw at the bottom should also be removed (can’t tell if it’s touching the panel or not, but it shouldn’t be.)
That’s what I thought, I just wanted to make sure, and yes, the green screw was attached to the panel. It was just so obvious that they were separated, even with the grounds on the screw side that it made me paranoid there was some wacky new bar out there that’s insulated between the top and bottom… It’s been a long week already!
IF the feed is corrected to provide 4 conductors as it should be, the green screw would be required to bond the ground conductor to the panel.
In my experience the bond screw is only used to bond the neutral bar to the can. If it is not needed it is not used elsewhere.
Auxillary ground bars bond to the can with their mounting screws and they are much smaller.
How would you know when the bond screw would be needed to bond it to the neutral? How can you tell if it is needed or not?
The bus bars need to be bonded to each other and to the panel in the case of a main panel (where the shutoff is.) In all other cases (it’s my understanding) the neutrals, grounds and panels are not bonded to each other.
I believe that is not quite correct, Mark. In the case of a sub-panel, the ground bar is bonded to the panel through its mounting screws.
If that were the case, then wouldn’t the neutral bar also be bonded to the panel through its mounting screws, thus making a neutral/ground connection in the sub panel (which wouldn’t be correct)?
In a remote distribution panel (sub) the grounded conductors (neutrals) are isolated from the panel board and the grounding conductors (grounds). The grounding conductors (grounds) are bonded to the panel board.
I’ll grant you that, but not through the mounting screws. If that were the case, the mounting screws of the neutrals would also be bonded to the panel via their own mounting screws.