I am looking to start a detached garage project (residential) this spring coming up and am starting to do some in-depth research about each area, my questions here are related to electrical service to the garage. I intend to also ask this question on a garage forum to cast a wide net. I live in Michigan and my township currently adheres to 2011 NEC. 1. I am leaning to 100 amp service since it feels like from a practical standpoint it is either 60 amp or 100 amp and I have never heard anyone regret going larger. House service is 200 amp. The service will be 220/240V, from research so far it seems like 100 amp may be a order of magnitude more difficult / expensive to do, but I do know that upgrading 60 amp to 100 amp after complete is much, much more difficult. My question is what can I do with 100 amp that I cannot do with 60? I intend to enjoy this garage for many many years and will likely get into welding and upgrade to a two stage air-compressor at some point. 2. My understanding is that the wiring of the subpanel to detached garage (regardless of 100 vs. 60 amp) is the first diagram in [URL="http://www.doityourself.com/forum/electrical-ac-dc/495452-sub-panel-diagrams.html"]this[/URL] post. Is this correct? 3. My main question is I have not been able to nail down the actual wire that is required and I have many questions here (assuming 100 amp service): a. My current understanding is that I need to run bundled wire (e.g., Romex style) inside the house (and garage), but outside (underground) I have to run USE-2 style THWN or XHHW wire (e.g., 2-2-2-4) within conduit. I cannot use the USE-2 inside the structures, and I cannot use the inside wire outside underground. In the past I have ran 60 amp service to a detached garage using 6/3 UF-B WG wire for the whole run, that was many years ago and I am not sure if that is still the way 60 amp would be done. This seems to be the main reason why 100 amp service is more difficult / expensive (other than for the obvious larger wire) b. Copper vs. Aluminum - I believe I have to use at least #2 Aluminum and #3 Copper, maybe more based on length (subpanel will be close to but within 200' of main house panel). Does the ground need to be #6 or #4? Is there a reason to go copper over aluminum, I know the latter is cheaper? c. THWN vs. XHHW - I believe this is the insulation (and can be mixed and matched with Copper or Aluminum), is there an advantage / disadvantage to either one? A recommendation either way? d. Converting outside wire to inside wire (at both house and garage). I am led to believe that you mount junction boxes to each structure (outside) and that is where you convert the wire. Is this correct? I would imagine the box mounts to the structure and has the inside wire go through the back and the outside wire within conduit that goes down from the junction box into the ground. Is this correct as well? e. Any other items I have missed that I should know about? Thanks in advance, I am eager to learn and make sure I do this right.

Hello - I received such fast & great help on my last post with a bathroom light/fan - hoping I can get the same here assuming I describe my issue correctly :) I have a outdoor timer switch that has gone bad - & I think it's from the electrician who last put it in (when doing some other work). My thought is that the timer either is just bad or the wiring is wrong - & I'm leaning on the latter since this was only my 2nd switch in 10 years (before any major work was done in the house). Per the 2 pics - the first is the current state & the 2nd includes that and the new switch. My uncertainty is in the wiring of the new - I did try it & got "close" - but I know it wasn't right b/c the on/off did nothing & the lights stayed on full time. So with the new - there are 5 wires vs. 3 (now black, blue, red, green, white vs. the black, blue, red). Is it as simple as just matching up the colors again & capping off the white/green? Or - if I assume my current wiring is incorrect - do the pictures help illustrate what may be wrong? All insights appreciated & I can willingly answer more questions / take pics as necessary! --ST[ATTACH]43686[/ATTACH][ATTACH]43687[/ATTACH]