×
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

Drawbridge motor & controller upgrades

Drawbridge motor & controller upgrades

Drawbridge motor & controller upgrades

(OP)
Does anyone have experience with upgrading the control system & drive motor for a motor operated drawbridge? We are investigating upgrades to an existing drawbridge that uses a 30 HP wound rotor motor and a resistor bank for speed control. Is anyone familiar with using an "off the shelf" induction motor for such an application, & what sort of control system is typically used? I would welcome any ideas and recommendations.

RE: Drawbridge motor & controller upgrades

   I have never seen a drawbridge drive but I don't see why you cannot use an AC drive for this.  You have to make sure all the safety interlocks are in place.  More importantly, when lowering the bridge, the drive will most likely be regenerating and it may be doing this rather heavily.  This energy will have to go somewhere and you only have two choices.  An active front end (regenerative) which will put the power back on the line or DB resistors.  If DB is the choice, it is unlikely the standard DB circuit in an AC drive can handle this load so you should take great care that both the DB resistors and the IBGT for braking are sized correctly.  I would think you would have to supply an external braking controller for this.
   I have to assume there is some kind of mechanical brake with interlocking, similar to what would be on a hoist drive for safety.

RE: Drawbridge motor & controller upgrades

A company I used to work for did stuff like this. You may want to check out this application note:

http://www.systems-interface.com/ver4/app/montlake.pdf

I am in no way trying to promote their services, this is just a project I knew about.

xnuke

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

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