Service to #2 detached bldg questions

[hotrodA]

I have 100A service to my detached shop from my 200A house panel which has a breaker for it. The detached shop has a 100A panel with main breaker also.

I want to continue 30A, from the 100A panel, 120 feet, on to an additonal detached bldg for lights and recpt. 10/2 (?) on its on breaker.

The first 80 feet on this run will be indoors, but last 40 feet will have to be buried in PVC.

My question is/are:
Will NEC code allow me to split the indoor and outdoor wire at a junction box either inside or outside the first bldg. before the PVC, and then split it at another box for the light and recpt circuits at the 2nd detached bldg? Or do I have to run continuous outdoor all the way? Does the service connection have to be uninterrupted?

And/Or can I add another sub panel in the last building with the two breakers for lights and recpts, for a couple of T-12's and table saw.

Also looks like a 2nd (or double) ground rod will be needed, right?

Suggestions, Please. Thanks!

 

[Charles (in GA)]

I have 100A service to my detached shop from my 200A house panel which has a breaker for it. The detached shop has a 100A panel with main breaker also.

I want to continue 30A, from the 100A panel, 120 feet, on to an additonal detached bldg for lights and recpt. 10/2 (?) on its on breaker.

The first 80 feet on this run will be indoors, but last 40 feet will have to be buried in PVC.

My question is/are:
Will NEC code allow me to split the indoor and outdoor wire at a junction box either inside or outside the first bldg. before the PVC, and then split it at another box for the light and recpt circuits at the 2nd detached bldg? Or do I have to run continuous outdoor all the way? Does the service connection have to be uninterrupted?

And/Or can I add another sub panel in the last building with the two breakers for lights and recpts, for a couple of T-12's and table saw.

Also looks like a 2nd (or double) ground rod will be needed, right?

Suggestions, Please. Thanks!

Treat the second building just like the first, four wire to it, a disconnect, main breaker, etc if over six handles in the second building, and two ground rods, etc.

No restriction of the splices, just do it right and make good connections.

Might consider up sizing the wire, as this is a long run and you will be placing some pretty heavy loads on it with a saw and lights running.

Charles

 

[hotrodA]

Thanks, Charles, for the response. I like the suggestions of the 4 wire run and the size upgrade. I was most concerned with the junction box connections. It sure saves on the wire costs.

Anybody else care to chime in or add on?

Thanks for the help!

 

[1Garageman]

Charles knows his stuff!

 

[bjcouche]

Charles is correct.
You might want to look at using 10/3 (with ground) UF cable so that you can use that cable indoors and underground without having to add junction boxes. You would only need the small subpanel in the last building. Ground rods to. There you would have breakers for your 120 and 240v loads. There is nothing wrong with having junction boxes to switch from indoor to outdoor cable. You just have to leave them accessible and not bury them behind drywall. Usually though, adding boxes instead of just using UF indoors, the boxes get the cost up, although at 10awg you're still in a fairly small box and in "wire nut territory".
I am doing something similar to what you were thinking of. I went from my house panel, using 1awg copper, to a junction box in the house (with big lugs) and then from the junction box using 4/O, 4/O, 2/O, 2awg aluminum to the garage. Using way larger aluminum "feeder cable" was much less expensive than smaller copper. I only have a 100A feeder breaker but that cable was the cheapest way to get 100A with low voltage drop that distance.
Brian