Jump to content


Photo

How to configure time for starting motor??


  • Please log in to reply
5 replies to this topic

#1 angga1

angga1

  • Members
  • Pip
  • 1 posts

Posted 06 October 2002 - 10:18 AM

i'm really didn't understand , about how to configuring time for starting motor . in my project is 1 phase motor using three part of resistances (with Direct OnLine method) . my problem is how to determining time starting value , is it any calculation method ?? could anyone help me please...cause it is very urgently , if anyone could share , can sending me a details to my email

#2 marke

marke

    Posting Freak

  • Moderator
  • PipPipPipPipPipPip
  • 2,651 posts
  • Gender:Male
  • Location:Christchurch, New Zealand

Posted 08 October 2002 - 08:37 AM

Hello angga1
Welcome to the forum
The starting time is dependant on the motor characteristics and the load characteristics. You need to keep the voltage reduced as long as the motor continues to accelerate. If you switch too early, the current will go very high. If you switch too late, the start time will be prolonged and the motor will heat up.
Best regards,

#3 Jacky

Jacky

    Junior Member

  • Full Member
  • PipPip
  • 6 posts

Posted 26 November 2006 - 06:27 AM

It means that the starting time must be refer to the motor maker?

#4 AB2005

AB2005

    Senior Member

  • Full Member
  • PipPipPipPipPip
  • 411 posts
  • Gender:Male

Posted 27 November 2006 - 02:12 AM

QUOTE(Jacky @ Nov 26 2006, 11:27 AM) View Post

It means that the starting time must be refer to the motor maker?


Dear Jacky,

No, if load is coupled with motor through a magnetic clutch and motor starts independently, then you can say "starting time must be refer to the motor maker". If motor is direct coupled with load then Mark's comments would be applied "The starting time is dependant on the motor characteristics and the load characteristics".

"Don't assume any thing, always check/ask and clear yourself".


#5 mull982

mull982

    Junior Member

  • Members
  • PipPip
  • 3 posts

Posted 17 March 2008 - 12:28 PM

QUOTE (marke @ Oct 8 2002, 03:37 AM) <{POST_SNAPBACK}>
Hello angga1
Welcome to the forum
The starting time is dependant on the motor characteristics and the load characteristics. You need to keep the voltage reduced as long as the motor continues to accelerate. If you switch too early, the current will go very high. If you switch too late, the start time will be prolonged and the motor will heat up.
Best regards,


Marke

Can you please explain why this is? I am having a similar problem of switching time and am trying to learn the science behind what you just explained above. I am having a hard time understanding why switching too early causes current to go high?

Thanks for the hlep.

#6 bkelly95

bkelly95

  • Members
  • Pip
  • 1 posts

Posted 21 July 2009 - 01:21 PM

QUOTE (mull982 @ Mar 17 2008, 01:28 PM) <{POST_SNAPBACK}>
Marke

Can you please explain why this is? I am having a similar problem of switching time and am trying to learn the science behind what you just explained above. I am having a hard time understanding why switching too early causes current to go high?

Thanks for the hlep.


My guess is - When the motor starts the current is flowing in the stator windings' copper with little resistance as the back emf has not had time to build up as there is little or no rotation. When the rotation builds up, so does the flux and there is a resistance - hence the current drops to normal running current.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users