i have question about feeding a pole barn. Can I use Table 310.15B7 to figure out wire size? The barn is 400 feet from the house. I want 100amps but other contractor is telling him 60amps. I was using Southwire Voltage drop calcuator to figure the wire size and voltage drop. I'm thinking if I use table 310.15B7 the wire size is smaller than Southwire. Less money. My thinking is if you're going to feed barn how much different in price is there between 60 and 100 amps. Sorry , hope I didn't confuse everyone. Might be two questions here.
feeder run
- Thread starter guschash
- Start date
- Status
JFletcher
Senior Member
- Location
- Williamsburg, VA
The southwire calculator will give a larger size here due to the distance. NEC does not require you to compensate for voltage drop. What is the calculated load for the subpanel?
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
You can't use that table for anything other than a dwelling. You would need to use the Ampacity Tables (310.15(B)(16)) for a barn.
You need to figure out the max load you need for the barn and size the conductors according to 310.15(B)(16).
Then if you want to figure for VD then use Southwire's calculator.
You need to figure out the max load you need for the barn and size the conductors according to 310.15(B)(16).
Then if you want to figure for VD then use Southwire's calculator.
- Occupation
- Licensed Electrician
2-2-4-6 mobile home feeder cable tied to a 90A breaker. That's probably all you will ever need. Run conduit if you want to hedge on future loads.
The biggest question here is whether the barn is just a barn or is it to be used as something else? If it is just a barn, is it an animal barn, storage barn, etc.?
What it amounts to is what is the anticipated load? Given he already has lights and receptacles, if the owner wants greater capacity at the barn, he has some idea of what the load will be.
What it amounts to is what is the anticipated load? Given he already has lights and receptacles, if the owner wants greater capacity at the barn, he has some idea of what the load will be.
- Status