How many ground wires can go under one ground screw on a ground bar? And were can I find that in the NEC.
Thank You
See 110.3(B)
Basically, read the ground bar manufacturer's instructions.
Al
You need to look at the instructions with the ground bar or in the panel the ground bar is designed to fit. If nothing is said about installing multiple wires per hole the maximum would be one. The NEC does not specifically state the number of conductors. It is up to the manufacture of the panel and ground bar.
110.14(A)and 408.21
Joe Tedesco covers this topic...
https://www.electrical-contractor.net/ubb/Forum4/HTML/000061.html here's a few pictures from Joe's archive
3-way