×
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

Motor cooling as function of speed

Motor cooling as function of speed

Motor cooling as function of speed

(OP)
Hello all,

I have been scouring the internet including as many threads as I could find in relation to motor cooling as a function of speed/frequency. I cannot find it in any motor protection standard or white paper across multiple manufacturers (including IEEE stds, GE industrial practice handbooks, induction motor textbooks, etc.). Does anyone have any idea where I may find a table of values or cooling curves for TEFC motors up to 5000HP (ie. heat dissipated as function of motor fan speed).

The reason I need this is I am trying to apply minimum load value (A) at zero speed for a motor relay setting.


Any help would be appreciated.

Thanks.

RE: Motor cooling as function of speed

There are so many variables associated with what you ask that I cannot believe the curves you're looking for exist.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor cooling as function of speed

The reason I need this is I am trying to apply minimum load value (A) at zero speed for a motor relay setting.

for a single motor. Sounds like you do not need to research all motors?

This would be a very easy answer if you just ask this particular motor's manufacturer; I am sure they can tell you very quickly what maximum load THAT motor can have at 0 speed.

Typically for a TEFC asynchronous motor it is always 0 load without additional cooling. Not just 0 load, but you cannot even leave it powered on as the I^2*R losses just from the magnetizing current alone will overheat it.

www.KilroyWasHere<dot>com

RE: Motor cooling as function of speed

Out of the box, methinks you just have to consider a separate cooling motor blower to blowoff heat from your motor. It's simpler, imho.

RE: Motor cooling as function of speed

Hello ZeroSeq

Just take account the rules for fans, when you operate the motor a speeds below rated speed the fan will move less volume of air, this is why manny motors are driven with VFDs are cooled with forced air.(external ventilation at constant speed).

For this matters is better taht you can consult EASA, they have a great group of experts that can provide you solutions also you can take a look of the book Fan Handbook of Frank P. Bleier.

Regards

Carlos

RE: Motor cooling as function of speed

(OP)
Thanks for the responses, I kind of figured I would not be able to find such information.

Mike, you are correct it is for a specific motor and I will have to go back to the manufacturer for more information. I was basically looking for an easy fix so I didn't have to do that, which is like pulling teeth.

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