[Bootes]

For the last week I have been pouring over 10s maybe 100s of threads describing how to do this. I have come a long way but I still have a few questions.

My plan so far...

I will install a dual pole 60A breaker in my main 100A panel in the basement. From there I will run 4 #6 THHN wires (2 hots 1 neutral 1 ground) out of the basement, through PVC conduit to the exterior shop. In the shop will be a main breaker sub panel with an additional bus for equipment ground (I know to keep grounds and neutrals separate in the sub).

There seems to be a lot of confusion as to whether the sub panel should be grounded via copper grounding rods driven into the earth along with the ground from the main panel. Some people say that because it is not attached to the house grounding rods MUST be used. Others say that would violate code because there should only be ONE place where the ground should meet the earth. I have e-mailed my local electrical inspector on this matter, so I will just do what ever he says.

I originally intended to run a 6-3(with ground) from the main panel, across the basement, underground (in PVC) then through the shop wall to the sub, but as I read, you cannot run a "cable" like that through conduit, instead I need to run 4 individual conductors. Ok... but I can't imagine I can run these 4 conductors across the basement, and threw the shop walls without some sort of "protection". So do I run conduit all the way across the basement, underground, and through the wall to the sub? Ive been told conduit should not be used inside unless the wires are in danger of physical damage. Running trough studs and floor Joices is hardly an argument for that exception. So then maybe I can run the 6-3 across the basement into a junction box where it enters the underground conduit and switch to the single conductor THHN. On the other side have another junction box and switch back to the 6-3 to run through the wall to the sub. How would you connect two wires of this size inside a junction box anyway? Wire nuts? What is used to connect even larger wires say #4 or #2, seems like wire nuts wouldn't give adequate connectivity.

Just want to clarify:
Because this is a separate structure there needs to be a disconnect AT the structure (so the 60A breaker on the main panel doesn't count). So I can ether install a main breaker sub panel, or install a main lug sub panel with a disconnect box next to it. Is this correct?

Thanks in advance

[stanfortyman]

You actually do have a very good handle on it.

I will install a dual pole 60A breaker in my main 100A panel in the basement. From there I will run 4 #6 THHN wires (2 hots 1 neutral 1 ground) out of the basement, through PVC conduit to the exterior shop. In the shop will be a main breaker sub panel with an additional bus for equipment ground (I know to keep grounds and neutrals separate in the sub).

Good so far.

There seems to be a lot of confusion as to whether or not the sub panel should be grounded via copper grounding rods driven into the earth along with the ground from the main panel. Some people say that because it is not attached to the house grounding rods MUST be used. Others say that would violate code because there should only be ONE place where the ground should meet the earth. I have e-mailed my local electrical inspector on this matter, so I will just do what ever he says.

A detached structure with a feeder, as opposed to one circuit, MUST have a grounding electrode system. Typically this is a ground rod or two.
This grounding electrode serves a completely different purpose that the equipment ground you run with the feeder. The "earth" is NOT providing your safety ground that you run with branch circuits. The equipment ground is.

So then maybe I can run the 6-3 across the basement into a junction box where it enters the underground conduit and switch to the single conductor THHN. On the other side have another junction box and switch back to the 6-3 to run through the wall to the sub. How would you connect two wires of this size inside a junction box anyway? wire nuts? What is used to connect even larger wires say #4 or #2, seems like wire nuts wouldn't give adequate connectivity.

This is your best bet. You can use Polaris connectors to splice the wires. These are fully insulated splices with set screws you simply tighten down.
You'll need at least a 6x6 box for this splice.

Just want to clarify:
Because this is a separate structure there needs to be a disconnect AT the structure (so the 60A breaker on the main panel doesn't count). So I can ether install a main breaker sub panel, or install a main lug sub panel with a disconnect box next to it. Is this correct?

Exactly!
A main breaker panel is obviously much easier.

[Bootes]

It looks like my research as been paying off then! I thought of one more question:

If I use the 6-3 when not inside the conduit, and THHN inside the conduit, should my ground wire that runs through the conduit be a bare copper wire? Or green insulated? Is stranded wire OK for all of these conductors?

Thanks for your help Stan!

[Tev]

The wiring in the conduit must be stranded if it is 8 AWG or larger. That said, the equipment grounding conductor in this instance only needs to be 10 AWG so it can be solid or stranded. It's also your choice whether to use bare or insulated. I'd personally go with green insulated stranded wire.

The above equipment grounding conductor size is provided you are not going a distance that causes you to up-size the conductors because of voltage drop. If you do up-size then you will have to increase the equipment grounding conductor size also.

[KISS]

Wire used should be rated for wet locatons. THNN is not. THWN is. Most wire though is dual rated. e.g. THWN/THNN

You can run NM-B cable in conduit, but the conduit fill calcs have to be right as well as the feeder size.

A reminder that the breaker used at the remote location can be whatever size you like. e.g you can use a panel with a 200 A breaker if you desire. The 60A feed breaker must remain at 60A.

You may have to purchase a ground bar kit for your remote panel and remove the neutral to ground bonding screw.