This is service main panel ( Square D QO load center) . I have to add total 9 breakers. 7 breaker on left and remaining 2 on right side.
I am seeing earlier electrician ( during construction) put some neutral wires in the ground bar but just only one under one screw.
So I can also attach, but this time is "Neutral pigtail wire" ( coming from breaker) to a ground bar under a different unoccupied screw. right ?
Another question: Earlier electrician put up to 4 ground wires under one screw. so following the same rule in two places as it was passed by inspector, and also it was easy for me and didn't find space. In picture, There are 2 screw on right side which already each had 3 ground wires under. so I added one more to each of two screw/lug.
so my question, why electrician didn't put 4 ground wire under other screws when electrician can do. Is there condition or situation when no. of ground wire under one screw vary ?