I have a 200 amp service panel, (culter & hammer, BR type, 30 spaces) and need to make sure that the ground wire is connected properly. I have a ground wire connected to metal water pipes, and a ground rod. The wire is continuous and protected from damage by framing. How should the wire enter the service panel and be protected from damage? There are knockouts for nm cable clamps, conduit connectors and small knockout tabs (that appear to be designed to be just large enough for 4 or 6 AWG ground wire). So what type of hole can/should the ground wire come through to enter the service panel and how should it be secured so it it is not damaged entering the service panel? If it is supposed to enter through the small tabs, and the wire does not fit (I am using insulated wire and may over size it) can it come through one of the 1/2" knockouts and be clamped? Local codes do not dictate that the ground be protected by conduit while running through framing so I would rather avoid the hassle. Thanks for any info.

Usually there is a little hole made for just that.