Length of conductor

[ansinspect]

What size conductor should be used to connect a 100 amp sub-panel 225 feet away from the service panel (200 amp) conductor would be underground in conduiet.

 

[petersonra]

What size conductor should be used to connect a 100 amp sub-panel 225 feet away from the service panel (200 amp) conductor would be underground in conduiet.

could be just about any size.

depends on the load required, the voltage drop you are willing to accept, and the feeder OCPD size.

why would anyone run this in conduit anyway? UF is probably the most cost effective solution.

some additional information is in order.

 

[charlie b]

Is this something you came across during a home inspection, and are you trying to determine whether you should include a recommendation to the owner? If so, what size and type of wire is there now?

 

[krsparky]

# 3 is rated for 100 amps in the 75 degree column of table 310-16 in the NEC.

The voltage drop is directly related to the load. If you google voltage drop calculators you will find allo kinds of free ones.

I really don't think you have a large voltage drop concern, if you go one size bigger to a # 2 copper conductor I am sure you will be more than covered.

Keep it in conduit, you will be better off in the long run.

Remember to follow the rules for detached garages or buildings. Main breakler required.

 

[infinity]

We need more information to properly answer the question. What is the connected load would be a good place to start. Then you can use this:

http://www.electrician2.com/calculators/vd_calculatoradv.htm

 

[roger]

Why not just note on your report that it may be advisable to have an electrician check this item.

Even if you find a VD calculator you can use, there are to many variables for misdiagnosing whether there is a problem or not.

Roger

 

[mdshunk]

Lacking print specs, I'd run #12 on a 15 amp breaker and have a fat change order ready.