Concerning the 2005 NEC is this a true statement, and can you tell me where in the book it is?
Question:300' is as far as any code will let you go and for good reason. At 700' even with a larger gauge of wire your not going to get much electricity. Its a resistance thing.
Answers:
This is false.
Basically, you are talking about voltage drop. As the legnth of a run increases, you have to increase the circular mils (or size) of the wire.
The NEC requires that there will be no voltage drop allowance at all. You will find in ARTICLE 90-4 in the NEC that “judgment calls” are up to the Authority Having Jurisdiction. Therefore, the Authority Having Jurisdiction has the authority to allow the use of the FPN note speaking of 3% on a branch, or feeder, and with a total voltage drop of 5% on the feeder, and branch combined. This NEC FPN Note can be used as an allowance for you to use that is within the authority of his judgment. Otherwise the NEC flat says that the conductor must be able to carry the load as computed in Article 220.
you can review the 2005 NEC at your main library branch, in the reference section. 300' is not far, if you use the correct gauge wire. An electrician or Mechanical Engineer can calculate line loss to determine the wire size to provide you with adequate amperage at your destination. If the run is real long consider a step-up / step-down transformer.
The total resistance of a wire / cable is of its total length. In other words, the greater the length the greater the resistance - longer wire more resistance.
Also, the greater the distance the larger the power losses. These losses are generally through the current traveling through the wire over great distances. Therefore, to reduce power losses it is standard procedure to increase the voltage ( thereby reducing the current), so the losses will be reduced.
About the receiving end you will need a step-down transformer to reduce voltage and increase current.
this is the reason the elec. company transmits high voltage power to the pole, reduces it to send to your house - to reduce losses.
As far as limitations on length you will have to check your local electric code - or check with your town's code enforcement officer.
Not true. You can run a circuit as deep as your pockets are.
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