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

pump soft start

pump soft start

pump soft start

need help, is there any way possible to do a 65% soft start on a 10 hp, single phase pump motor short of going through a phase converter? Any help would be appreciated. Thanks

RE: pump soft start

A resister, a big resister would be the simplest way of doing that. But on single phase, 65% voltage, you will more than likely burn the start windings or blow the caps since the start winding will stay in too long!

Why do you want to soft start it?

I buy a lot of stuff from my local "irrigator" supplier. You in FL?

RE: pump soft start

Suggestion: Also, a voltage regulating autotransformer could be considered. It would give you a chance to vary voltage without losses and lower speed somewhat, if needed. The resistor resistance vary and it can burn in time.

RE: pump soft start

If this is a capacitor start winding, then it is possible to soft start or reduce voltage start the motor. If the motor is an induction start, then reduced voltage starting is not very effective.

To soft start, leave full voltage on the startwinding (with capacitor) and apply a single phase soft starter to the run winding only.

Mark Empson

RE: pump soft start

Can you changer out the motor?  If you can I would change the single phase 10 HP motor for a 3 phase motor and use a VFD with a single phase input.  Call around and check prices. I think it would be cheaper than buying some kind of reduced voltage starter for a 10  HP single phase motor.  If you ever had trouble with the motor ( three phase motors are more reliable) in the future it's wasier to get a 10 HP three phase than a single phase.  

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


White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now

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