I have a distance of about 250 feet that I want to put electricity to a building from my existing meter pole. I would like to know what size wire to put in the ground.

Use: a few small cabins (12'x16', 12'x12', and another 12'x12'). The cabins will have a window unit A/C, a small refrigerator, and possibly run an air compressor or some power tools once in a while.

The service is about 250 feet away from the pole. I plan on burying the cable. I also have to run through a small creek (not usually wet). 100amp meter pole (already there).

What do you recommend?

You can use aluminum wire rated for direct burial, called URD (Underground Residential Distribution) cable.

This comes in 3 and 4 wire, if the main breaker is at the meter, then use 4 wire, if the main breaker is at the cabin, then only 3 wire is needed.

Assuming a 50 amp load, #1/0 Al will get you a 3.2 % voltage drop. If you can afford it, esp if you plan to add more load later, then I really recommend using #4/0 Al URD cable. This will allow 100 amps of load at 3.6% Vd.

Please forgive my ignorance, but I would also like to understand more about what you are suggesting...
I have heard of direct burial cable, but I am not sure if the cost of 250 feet will be really significant or not. I priced THHN and for number to the electric company quoted $1.28 per foot. I also priced Direct Burial (3 number 2's with a ground) it was about $5.93 per foot. Does that sound about average? Number 4 was $.81 and $4.15 respectively.
Is there a difference in "Number 4" and "#4/0"? (again, please forgive my ignorance... that is why I am here at the site for advice)

All your prices seem reasonable, I am assuming the #2 THHN is copper, and that the direct burial is aluminum.


Forget THHN, that is for dry locations only, not allowed in wet locations, which would be a conduit underground.

Most THHN is also rated THWN which can be used in underground conduit. THHN/THWN must always be in a conduit, never direct buried.

The smaller the number the larger the wire, #12, #10, #8, #6, #4, #3, #2, #1, #1/0, #2/0, #3/0, #4/0. The "0" stops there, and starts with the actual circular mils called MCM. Ok enough on wire sizes.

If you use #2 copper, there will be a 3.2% Vd with a 40 amp 120 volt load.

If you use #2 aluminum, there will be a 4.5% Vd with a 40 amp 120 volt load.

I should explain that the maximum recommended voltage drop is 3% for a feeder, and 2% for a branch circuit to the last outlet.

With the AC and motors you mention, really need to keep the Vd as close to or below 3% as much as practical.

I have talked to several people here locally (friends, not electricians). They are mostly telling me to stay away from aluminum (because of corrosion and heat). The cost is about 75% less for aluminum. Should I stay away? What are your thoughts?

FYI #4/0 is the same as 0000. Just like purity numbers of 5N5 is 99.9995% pure, but that another area all together. It's just shorthand.

Kiss, sounds like 5N5 is purer than Tripple Nine Fine?

See, I'm not making it up.

Virtual Travelog | 5 Nines and other Nonsense - Interaction of Quality Attributes in System Design (http://www.virtualtravelog.net/entries/2003/01/5_nines_and_other_nonsense_interaction_of_quality_ attributes_in_system_design.html)

Type as a Google search "5N5 purity"

Hi, Aluminum is less reliable (cheaper).. copper is the best.