×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

TEFC vs Open

TEFC vs Open

TEFC vs Open

(OP)
Looking around our plant I see several very similar motors (100hp, 3600 rpm) driving centrifugal pumps in similar environments (slightly humid, no corrosive chemicals, ambient <40C).  All were spec'd and purchased in the 1980's and have class B insulation.

I doubt that we specifically asked for TEFC... since doesn't appear it was required by the environment.  Is it possible that we left the choice open and the supplier supplied TEFC because it was cheaper?

Any thoughts?

RE: TEFC vs Open

Generally, TEFC is more expensive than an ODP motor of the same HP/speed. As well, for a given HP/speed, an ODP motor will (can) be one frame size smaller than a TEFC motor of the same rating.

As to why some of your applications are TEFC and some ODP when all else is the same....who knows? In general, my impression is that TEFC motors are more commonly produced now than ODP, where 25-30 years ago the opposite may have been true. If so, maybe you are seeing the transition period reflected in your equipment. Of course, that is not to say that ODP motors are not produced or used. In fact, (again an impression), these days the most common new applications that I see them in are by manufacturers of 'packaged' compressors and pumps. I believe that this is because of the smaller frame size and more so because of lower cost. (remember these are the same ones who usually size a motor to run at service factor...)

RE: TEFC vs Open

Suggestion:
TEFC motors may be designed, based on some economical analysis, if some record shows that the light humidity is causing downtime, double-ended pipe ruptures damage open motors more than TEFC, and perhaps or habitually pumps and associated piping have traveling condensed water on pipes and other equipment, including debris, right into open motors.

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! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close