I am not a electrician but, did take a first year apprentice course years ago.
And I was taught there and it was stressed NEVER put Nuetral wires and Graounding wires on the same buses. Actually I can be corrected but, I thought there was a Neutral bus bar and a seperate Grounding bar.
Neutral wiring still carries current after it passes through a appliance which takes it to the Neutral bar. Which I was always under the assumption that it was an isolated bar that is linked to the Neutral wire coming into the home and takes the load back to the Power company. The ground bus bar is wher all grounds tie into go to the grounding rod or water pipe if you are in a town.
