I moved about a year ago and the "new to me" house has limited electric in the attached garage. The garage is at the same level as the basement as the house is somewhat built into a hill. Now I would like to add a sub-panel in the garage for the workshop. I have read a bunch of old posts on sub-panels but I still have some questions in an effort to avoid doing something wrong. I did a bit of wiring in my old house and will have an electricial friend do the connections at the main panel. The main electric panel is on the opposite side of the basement from where I want the sub-panel. Probably a run of around 50-60 feet. I will have to run the wire from the main panel to the sub-panel via the basement ceiling/1st floor joists. The basement has a dropped ceiling and the rafters overhead run perpendicular to the direction of the cable (i.e. the rafters run front to back and I need the electric line to go side to side). I will most likely use a 100 amp panel for the shop sub-panel to "give me room" and feed it with a smaller sized breaker in the mail panel.
Questions:
1. I think a 60 amp sub-panel should be fine. The most I can ever see running at the same time will be a 3hp machine (20 amp circuit) and the 1 1/2hp dust collector (15amp circuit). The lights will be tied into the main panel and not run through the sub-panel. Do you think a 60 amp will do? Even if I get a 5hp machine (30amp) in the future, do you think 60 amps is OK?
2. My next question is related to wire size & type. I would like to use 6/3 with ground non-metalic (i.e. Romex) as it will be the easiest to run (conduit would be a real pain). I have read on-line that it is OK to run 6/3 attached directly to the bottom of the basement's ceiling joints and then will run it in conduit when it goes into the garage as the garage walls are block wall to the sub-panel. Is 6/3 Romex and my plan of hanging it to bottom of the ceiling joints OK? Is their any concern that there is a dropped ceiling covering this (any given tile in the dropped ceiling is removable in seconds and the dropped ceiling is a few inches below the bottom of the joists)?
3. Do you see any other problems with my plan?
Thanks in advance.
Mike