Voltage Drop

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guschash

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Ohio
Trying to figure out voltage drop for receptacles in a barn. Farthest receptacle is 180 feet . Using #12 I get 7.131 VD , #10 I get 4.485 , #8 I get 2.821. (117 volts). Now I can see using #8 receptacles but what about the LED lights at 200ft?
 
You need to know the expected load at to calculate VD. Don't use the size of the breaker. Your lights will be spread out evenly so that helps. Use a higher voltage for them as well.

Do yourself and the customer a favor by putting in a feeder for a panel at the far end of the building. I would consider the #10s for known loads such as Engine block heaters. They just about require one circuit per anyway.
 
guschash said:
thank you for responding . Real good ideas. I was using breaker size not actual load size.
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If you only have a 13 amp load instead of a 20 amp load that makes a difference.

If load is unknown you have to decide what you want to be worst case. If you have loads with a starting inrush, you have to decide how much of that you want to account for vs what it may draw during running.

Lighting - often you are running from one light to another and load is less after each one of them so you don't have the same VD in the last section of the run as you have in the first section.
 
Well IMO you should consider a #4 out there and on a 60 Amp breaker, It gets foggy
about the type of wire to maintain the Amperage verses wire type available which is not the basis of the OP's question.

As soon as one lights it up there, someone's going to want to start using some power tools.

Not less than 60 Amps Article 225.39 (D), not to mention Article 220.102 Farm Loads,
and Article 547 Agricultural Buildings.
 
cadpoint said:
Well IMO you should consider a #4 out there and on a 60 Amp breaker, It gets foggy
about the type of wire to maintain the Amperage verses wire type available which is not the basis of the OP's question.

As soon as one lights it up there, someone's going to want to start using some power tools.

Not less than 60 Amps Article 225.39 (D), not to mention Article 220.102 Farm Loads,
and Article 547 Agricultural Buildings.
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I think OP was asking about an individual 15 or 20 amp branch circuit supplying receptacle outlets.

180 foot length suggest is not some "hobby farm" either though is not too extreme. I've done many "barns" that are 800 - 1000 feet long, even worked in some that are nearly half mile long. Those half mile long ones had all 120 volt loads but only every so often through the building. On outside there was a 200 amp 480 volt feeder, with taps every so often to single phase transformers to serve those loads.
 
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