by wannabefree » Fri Dec 18, 2009 7:56 pm
If your single ground wire fails at any point you lose power to everything downstream. Wire is pretty cheap. I went the other way and ran separate runs to every fixture.
The other thing to think about is you will have more current flowing in the ground run that is closest to the ground block than anywhere else in the system. That portion of the run must be sized to carry the combined current of every fixture you plan to have on at once. So if you have three 5A loads that will be on simultaneously, you will have 15A in flowing between the ground block and the first load, 10A between the first and second fixture, and 5A between the second and third.
In anything at all, perfection is finally attained not when there is no longer anything to add, but when there is no longer anything to take away.
-- Antoine de Saint-Exupery