It's a one time expense of about $400 to go from #2 mhf to 2/0. Another $400 to move to 4/0. Not exactly an earth shattering sum to someone building a 30x40 shop.It's not the cost of the panel. It's the 300ft of wire that's gonna get you. I recently added a sub-panel to a separate storage building. Mine was only about 100ft from the house. I rented what I thought was a large enough trench digger from home depot but the soil is very hard and rocky so we had quite a bit of trouble digging the trench. It doesn't sound like you'll have that issue.
If the local electric company will run a separate meter to your garage, then I'd have them do that. If not, I'd go with aluminum wire over copper. I used 6 gauge aluminum xhhw-2. I felt like I only needed 50 amps but if you're looking for 125, you'll probably need to go with 2/0.
I paid just over $100 for the wire. If I had gone with copper, it would have been well over 3 times the price.
youre looking at the wrong column. you cannot protect #2 cu with a 130a breaker. the 90° column is for derating only. #2 cu is good for 115aI know 2 gauge thwn wire is rated at 130 amps. I don't know what gauge it would have to be for a 300ft run underground though.
or just use the formula i posted in the FAQ sticky. gotta be careful with some online calculators as they output a larger wire than is necessary.You want to use a voltage drop calculator to determine gauge required.
If you are considering running copper, I would strongly recommend rethinking that. Aluminum will be a fraction of the cost
no such thing as 250 ot (sp) wire. its 250mcm or KCMIL and triplex is not only the wrong # of conductors unless wired before 2008 but its usually single rated URD which is not permitted inside buildings. its not even an NEC recognized cable type.I ran 250 ot triplex for 200 amp service 300 ft out to my building no problems ata ll
It's a one time expense of about $400 to go from #2 mhf to 2/0. Another $400 to move to 4/0. Not exactly an earth shattering sum to someone building a 30x40 shop.
I'd bump up to at least 2/0 if this was my shop.
We all have our own budgets and priorities.I agree, not an earth shattering sum but the little things add up. For my purposes, I felt like 50 amps was already overdoing it so I didn't see a need to go with larger wire. I also couldn't find a valid reason to go with copper over aluminum.
Or an oversized one.A bit off topic but while you have the trench add a second conduit in case you later want to add solar panels on the garage and feed back to the house. Im redigging my trench a few years later. And also drop in some direct bury cat6 wire.
Plus you get to buy more tools!Im liking this idea. Just put the second building 300ft away put a vehicle lift inside it and just buy another air compressor for that building too. That was the reason for connecting the two buildings was to make it so all my tools stay in one building, but I guess it's not that big a deal to just have a second smaller toolbox another compressor etc.
You can't run low voltage and line voltage wire together in the same conduit. That's why he suggested a second one.Or an oversized one.
You have to use direct burial wire if you don't run conduit.I missed that part. The coax and internet cable don't have to be in conduit do they?