×
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

Water pump Wye/Delta Starter

Water pump Wye/Delta Starter

Water pump Wye/Delta Starter

(OP)
I am replacing three wye/delta 30kW motor starters. The existing starters are closed transition with a small resistor bank. The client wants to take out the the resistor bank because it frequently burns out and repairs are difficult and expensive. What are the implications of fitting an open transition starter for such an application?

RE: Water pump Wye/Delta Starter

Probably not noticable. Does the pump start OK when the resistor burns out? If yes, that's your answer.

Do you at all need a wye/delta start? They cause more problems than they solve. A soft starter is probably a lot better to put the money in.

Gunnar Englund
www.gke.org

RE: Water pump Wye/Delta Starter

Hello mpyke

Open transition starters create a very high transient that can cause electrical and mechanical problems and ideally should be avoided, however there are many open transition star delta starters in use in industry. See FAQ237-613 for more information on the open transition starters.
There is a very good chance that the resistors are not sized correctly to give a true closed transition performance and so the starter is effectively open transition even though it has the resistors fitted.
To work, the resistors need to be sized to handle around star current when in circuit. If they are small resistors rated in watts or even tens of watts, they will no be doing anything.

Best regards,

Mark Empson
http://www.lmphotonics.com

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