star grounding question...

Ooooooooooohhh!

So how does star grounding apply to an A/C sub panel? What my electrician did is run a 40 amp 65' 8 gauge non-armored A/C cable from the main A/C panel to the sub panel. I then have 4 20 amp 7' runs of 10/2 romex to my A/C sockets. The only ground rod that I have is a 10' 5/8" commercial grade ground rod that goes to my main A/C panel. Should I have a separate ground rod for the sub panel or a separate ground wire from the sub panel to the main panel or some other configuration? The system sounds great, but maybe there's something that I can do to get a lower noise floor. I plan on using cryoed breakers and already have good A/C sockets. I also plan on using Virtual Dynamics A/C wire to replace the 8 and 10 gauge wire that I have presently. Thanks! Stan

Talon4
65' #8 awg wire, that's kinda small wire for the distance. I am just guessing but the electrician installed 8-3 with/ground nmc, romex, for your sub panel feed. 2 hots, 1 neutral, and bare ground. The bare ground is terminated on the neutral/ground bar in your main electrical panel, just where it should be. Your sub panel is 120/240 volt, 40 amp rating.
Star grounding, "Nsgarch" said it well.
Inside your sub panel there is a separate bar for grounding. This ground bar is where the electrician connected the bare grd wire from the #8-3 w/grd feeder. This grd bar is also were the branch circuit equipment grds connect to. A common ground point, star ground.
No separate ground rod for a sub panel.

Jim

Jea48-Yes, that sounds accurate. I watched the whole process. Also, my electrician said that 8 gauge was okay up to 180', after that 6 gauge is the way to go. So are you saying that it is already star grounded? Any ideas are welcome. Thanks! Stan

Yes, it is star grounded.

Jim