Code Q&A

Code Q&A

Q. On a 1,600A 277/480V service, is the neutral conductor from the utility transformer to the service disconnect considered a current carrying conductor if the only line-to-neutral loads is a 200A lighting panel supplying non-linear loads?

A. The neutral (grounded) service conductor for this installation is considered a current carrying conductor for conductor ampacity adjustment purposes because a major portion of the load consists of nonlinear loads [310.15(B)(2)(a) and 310.15(B)(4)(c)].

Got a Code question for Mike? Send it to him at [email protected].

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.