electrical

6666 se hmm interesting:whistling2:

First off, this applies to all new posters. Put something more than "Electrical" in the title. This is the "Electrical" forum, I sure hope it is an electrical question.

OK, first off, WHY do you have to go overhead? I hope you realize this is much more difficult than underground.

Second, there is almost 100% change that you MUST run a "4-wire" feeder to the detached garage simply to meet code. In any case it is definitely a good idea.
No matter what, a detached structure supplied with a feeder MUST have a grounding electrode installed. Typically this is a ground rod (or two). If there is a metallic water pipe feeding the building that must be used as an electrode.
With the exception of the 4-wire feeder a detached structure get's treated basically the same as the supplying main building.

I'll try to do better ..... do as I would supplying the main building so I bond the Grounded and the grounding conductors in the sub -panel .

sub-panel in a detached garage

I'll try to do better ..... do as I would supplying the main building so I bond the Grounded and the grounding conductors in the sub -panel

How far is the garage? What loads are you going to have? You might want to consider voltage drop.

I would bury the line, aerial is much more difficult.

Ground from rods and pipe go to sub panel ground bar. You still need to run a ground to the house.

Neutrals are isolated from the frame and ground bar in a sub panel.