×
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

Temp limitation of conductors

Temp limitation of conductors

Temp limitation of conductors

(OP)
Looking at NEC code 110.14 (C) I am wondering if we were to install copper lugs (rated for 90deg.) on a machine disconnect that is rated for 75deg., would I then be able to use 90deg. rated conductors? I know it comes down to how the Inspector interprets it in the end. I just am trying to cut costs wherever I can.

RE: Temp limitation of conductors

The UL listing of the disconnect is based on the 75 deg C lugs. If you change out the lugs, you probably no longer have UL listed device. Also, you have to consider the terminations on the other end. Almost nothing in the low voltage realm is rated for use at 90 deg C ampacity - at least in the US.

RE: Temp limitation of conductors

(OP)
Thanks for the reply. I am not really replacing the connections to the switch. The clamp type connectors on most of the machines we get are not that good of a connection, and crimping on a ring terminal is another not so good of a connection, so we just use a type ML barrel post lug. It actually is used on both ends because the other end goes to a transformer. But, yeah I get where your coming from on the UL side of things.

RE: Temp limitation of conductors

I wouldn't go there. Scrimping on conductor size should probably be way down on your cost-saving list.

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