National Electrical Installation Standards

Standards as High as Your Own

 
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Monday, January 15, 2018

Question:

What is the correct gauge on a 600 ft 200 amp run aluminum conductors from the meter to the beaker box.

George Vazquez

A

Answer:

Hey George thanks for your question. If your question is about a single phase service for a dwelling unit then the ampacity can be 83 % of the service rating as stated in 310.15(B)(7) (1). If no ampacity adjustment factors or ambient temperature correction factors need to be applied 4/0 aluminum conductors are allowed as shown in the table in Example D7 in annex D.

Voltage drop limits are not generally required by the NEC but Informational Note No. 2 to 215.2(A)(1) indicates that 3 % for feeders and 5% for the total will provide a reasonable efficiency of operation. Energy codes and manufacturer's instructions can also have requirements. Here are some online tables and voltage drop calculators.

http://www.cerrowire.com/voltage-drop-table

http://www.southwire.com/support/voltage-drop-calculator.htm

http://www.calculator.net/voltage-drop-calculator.html

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