im familiar with a lot of wiring, I plan on rewiring the garage, it has a singe 110v circiut now, a couple switches to lights and 2 outlets, all on 1 swithc in the house


I want to run 220v out there to a small sub panel
220v outlet for future use(60/80 gallon air compressor and maybe a welder, these seem to be rated at ~20A and 30A respectively)
a couple 20A circuits with a couple outlets(probably about 4-5 duplex outlets on each circuit)
2 switched 15A circuits for lights

I plan to dig a trench, and run the plastic conduit, and will be running the individual conductors

the total run is probably right around 50', so, I'm thinking 8 gauge THHN wire?
for that run it looks like it provides for a 50A load ?  
so I am looking at a 50A breaker in the house?

also, do I run a hot, hot, neutral and a ground, or is a ground rod at the garage called for?

How big is the panel in the house and what kind of load does it currently have?

I'm at work now, I'll get that info when i have time

18" minimum depth for the NM conduit.  use an online "conduit fill calculator" to find the correct conduit size.


THWN is needed since buried conduit is classed as a wet location.
for 50A, you can use qty 3 #8 THWN's (L1, L2, N) and 1 #10 THWN for ground.


yes, that would provide 50A of split phase 240Vac.


4 wires: L1, L2, N, GND.   you also need qty 2 ground rods at the garage.

ar-jedi

Is the Garage attach to the house or is it separate from the house. If it is not attach to the house you will need to drive a ground rod at the garage also don't forget that subpanels must be 4 wire (2 hot's 1 neutral, and a ground)

When did #8 wire get rated for 50 amps?

several charts I've come across show that #8 is good for 55A, though the 50' run drops that to 50A



and to answer questions, detached garage, 100A service to the house, 6 open breaker locations in the box

is there a spacing between the ground rods set by code?  anything else I need to know?

Yes 6 foot  minimum if I am not mistaken.

#6 for 50A. Check local code on number of ground rods. We only had to drive one when I worked in Florida and Indiana as an electrician.

I am now leaning towards 2-2-4-6 MHF wire, it can be direct buried, needs to be inside conduit inside the structure, and its good up to 90A, so I would have no worries with a 50A breaker, pluss, its cheaper

and I'mm planning 2 8' grounding rods 6' apart