Any Actual "Electricians" Here?

[2LZ]

Got a question that seems to be above the heads of my usual general contractor buddies.

I have a single 200 amp main (disconnect) that comes in from the road, that breaks out to a sub-panel (with all the house breakers) that comes right up in the center of my house in the lower bathroom.

I need to tap off this 200 amp main and bring 100 amps underground out to my shop.

I've heard:

1- "You'll need to upgrade the panel."

2- "You can add a second buss bar to the existing main and run it out. Just drill a hole in the side of the box since you have no extra plugs."

3- "You need to run it from the sub-panel at the center of your house. The trenching will be costly."

4- "You're screwed. Get squirrel cages hooked up to solar panels with battery backup."

Any actual, knowledgeable, information would be greatly appreciated.

Here's a pic of the main. The power comes in to the meter on the left and drops down to the breaker from the top, then out the bottom to the house.

[Emerikol]

Step one would be to have a pretty good idea of your power requirements for the shop. You mentioned a 100 amp service, but do you need 100 amps, or is it just what you would like to have? One option that you didn't mention is to tap the back of the meter (on your side, not the un-metered side) and power an entire new panel. The limiting factor would be if you have a CL200 meter or something larger. Most residential homes have a CL200 meter, so just off the cuff I would be surprised if you have something larger. CL200 means that the meter is limited to 200 amps, and that would match what your panel is rated for. So back to step one: If you really [I]need[I] 100 amps, then you'll need to run it from the main and get the power company to upgrade your meter. You didn't mention how long the run was going to be, and what gauge wire you would be using. Since the branch is most likely going to be 240VAC, using 4/0 wire over 100' will only drop the voltage at the end by 0.8VAC. Negligible, in the great grand scheme of things. If you have a clear shot between the panel and the shop, trenching is going to be a cinch; just rent a trencher from Home Depot and go to town. Feel free to PM me if you have any other questions and don't want to clog up the post with back and forth problems and solutions. Hope this helps! BTW, I am NFPA-70e certified, and have wired everything up to 1080VAC in industrial applications. I usually play with 240VAC single-phase and 480VAC three-phase power, though.