Jump to content


Photo

Effect Of Increased Frequency.


  • Please log in to reply
2 replies to this topic

#1 rizwan

rizwan

    Intermediate Member

  • Full Member
  • PipPipPip
  • 10 posts

Posted 22 July 2007 - 04:25 PM

Hello,
We want to operate some motors, air conditioners and tube lights, rated for 220 volts 50 Hz, on 230 volts 60 hz power supply.
What would be the consequses ?
How can we minimize the effect ?
Do the increased voltage also contribute towards the effect ?

Thanks for any response.
Regards.
Rizwan Altaf

#2 chaterpilar

chaterpilar

    Member

  • Full Member
  • PipPipPipPip
  • 171 posts

Posted 23 July 2007 - 02:15 PM

Rizwan,

Increase in frequency will increase speed of motors by 20%,
and tubelights will have a flicker rate of 120 times per second as compared to 100 times per second when using 50 hz supply, which should not be a problem.

Chaterpilar

#3 marke

marke

    Posting Freak

  • Moderator
  • PipPipPipPipPipPip
  • 2,604 posts
  • Gender:Male
  • Location:Christchurch, New Zealand

Posted 23 July 2007 - 06:45 PM

Hello Rizwan

Operating motors designed for 220 volts 50Hz on 230 Volts 60 Hz will cause them to operate 20 % faster, and reduce the flux in the iron.
The increase in speed can lead to a dramatic increase in load, so the motors could be well over loaded at the higher speed. The reduction of flux in the iron, will make the motors slip more at rated load and therefore increase the heating in the motor. Essentially, the motor will need to be derated in terms of torque output.

You could use a variable frequency drive to run the motors at 50Hz off the 60Hz supply.

The tube lights, I assume that you are referring to flourescent tubes will have a ballast of some form. If the ballast is electronic, there will be no change with operation on 60Hz. If the ballast is inductive, the current into the tubes will reduce and the light output will be lower. If the ballast is capacitive, the current into the tubes will increase.

Best regards,




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users