×
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

dual speed 400hp, 480VAC motor

dual speed 400hp, 480VAC motor

dual speed 400hp, 480VAC motor

(OP)
fellow engr's,

bear with this gearhead...

existing 400hp, 480VAC electric motor driven by VFD (0-1800 rpm).

in the event of vfd failure, is it desired to operate motor at 50% speed (900 rpm).  best speed for maintaining controlability with process.  this means instead of a 4-pole motor for VFD operation, an 8-pole motor for direct line voltage operation.

is this possible?  a single motor with 2-windings or poles.

thanks for educating a gearhead.
-pmover

RE: dual speed 400hp, 480VAC motor

Yes, but it will mean a new motor. Buy a 2 speed 2 winding (2S2W) motor because the power circuit is simpler for interfacing with a VFD. You will still need to isolate the 2 power systems (VFD and Electro-mech) so there will be a lot of contactors and interlocks necessary, but there is no reason why it cannot be done. Find a good VFD integrator and explain the problem to them. Don't go with someone who does not understand the intricacies of mixing VFD and Line power to motors. You can blow out the VFD if it is done wrong, and a 400HP VFD is nothing to triffle with.

"Venditori de oleum-vipera non vigere excordis populi"


RE: dual speed 400hp, 480VAC motor

sounds to me like the best way out might be to get a standby drive

RE: dual speed 400hp, 480VAC motor

(OP)
jraef and panelman,

thanks for the responses.

yes, various standby drive units are being considered along with fluid drive couplings, magnetic couplings, etc.

there is a balance in meeting process conditions and what is most practical for situation.

a follow-up question, if selecting 2S2W motor, will motor footprint change as well?  - depends upon motor mfg?  trying to determine if foundation work needs to be accomplished.

thanks!
-pmover

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