×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

NFPA 79 control box wire size

NFPA 79 control box wire size

NFPA 79 control box wire size

(OP)
I have worked at several companies and everyone has a different interpetation of the NFPA 79 code for wire size in control box and on machine wiring. My current company is using 20AWG (UL not printed on wire also)inside the box from PLC to terminal blocks. And use 24AWG cable from box to descrete devices(sensors, etc).
I am talking about DC. I have always used 18AWG. Why can't they make the code cut and dry. Can someone clarify this as to code and not personal/company preference.

Jim

RE: NFPA 79 control box wire size

It's not interpretation or preference, it is absolut. It is all about current carrying capability, heat disipation and voltage drop. Maybe not simple calculations but calculations non the less.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources