Time for dedicated outlets!

cerberus79

#12 wire is rated for 20 amps and #10 is rated for 30 amps. If you use a 20 amp breaker it will trip at 85% of rating so what is the point of going to #10.

Derating the wire will reduce voltage drop. The calculation of the proper gauge wire for a given amperage hinges on the distance of the wire, so you can't quite say, " #12 wire is rated for 20 amps," although it is generally true.

bumperdoo

I grounded the sub-panel separate from the main panel using a grounding plate buried outside connected with 6-gauge grounding wire

That's a violation of the NEC and potentially hazardous. All grounds must be bonded together at the service panel, without exception.

The highest quality ground is a low impedance ground, and that's the ground provided by your utility. If there's an issue with your utility's ground, it's their responsibility to correct it.

Cleeds, that is true. If the run is 50 feet or more you should use # 10. If 100 ft  go to # 8.

10-3 was used for greater distance. My nextdoor neighbor who is a electrician ran that. So I have 2 20amp. At the wall we put 2 sets of outlets each set is on a separate breaker


Outlet. Outlet. Outlet Outlet
Outlet. Outley. Outlet Outlet
     1.          2.         1.        2
Breaker Breaker Breaker Breaker


It is this way so I can decide how much load is on each beaker.

Why are you guys using 10/3 Romex? What are you doing with the extra wire? 10/2 Romex has 2 insulated conductors and a bare ground. 10/3 has 3 insulated conductors and a bare ground.  Maybe you guys are confused about the wire naming? If not, I'm so curious what that extra wire is for!