royterk - is asking - I have reviewed several similar questions, however I am still a little confused. So, I will be running wire from my 200amp house panel to my new garage. This will be either direct burial or run in a 11/2" PVC schedule 40 conduit. I was told by an electrician whom I respect that I should put a 100amp panel in the garage. The anticipated use of electricity will be for lighting, garage door openers (2) and general plug in equipment (nothing to elaborate. What kind and size wire should I use from house panel to garage panel? Aluminum or copper? Keep in mind that future use may need more power than I intend to use right now.

The first question to ask is whether your panelboard will accept a 100 amp breaker. You should have that information in the documentation that came from the panelboard's manufacturer.

The next question is what are the listed temperatures of the main service panelboard and secondary panelboard.

If both are listed for 75 (C) then either #3 AWG Copper or #1 AWG Aluminum may be used, However, if either or both are listed for 60 (C) then #1 AWG Copper or #1/0 AWG Aluminum are your choices.

Next, how far from the panelboard is the garage and is the garage attached to the home? If the distance is greater than 100 ft. you would be wise to check for voltage drop issues.

The house panel will handle a 100amp breaker. The distance from the house panel to the garage panel is approximately 30 feet and is detached. The wire needs to be underground. I am not sure what AWG means. Is it okay for direct burial? Someone suggested UF #2 copper wire. Is that acceptable. Panels are listed for 75 (C).

"AWG" American Wire Gauge - the size of the cable.

"UF" is a type of insulation that is listed for use in the 60 (C) temperature only. #2 AWG is listed for 95 amps, not 100 amps, so the answer is no.#1 UF would work.

Personally I'd use USE cable as that is listed for 75 (C).

My final shot at this is as follows. After seeing all the information on the web I have concluded that all I need is a 60am panel in the garage. That said, I need to know which wire I should use (size and designation) for direct burial. Don - thank you for your help.

It's not that simple.

60 amp will require a 4 wire cable. If you are using copper, then a # 6 conductor listed for wet conditions. If you use UF, then you must use a # 4 UF cable will be needed.

Because the garage is separate, you must have a grounding system setup at the garage.