MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Electrical & Electronic > 60. Wiring & Cable Management
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Thu 07 November 2013, 03:23
andrewuk
Just call me: Andrew
 
leeds
United Kingdom
contactor

Hi its time to order the contactor ,ill be running a 2.2kw spindle but i am a little confused about the right contactor amperage, do i follow AC1 or AC3 specs i think it should be AC3 Thanks

Last edited by andrewuk; Thu 07 November 2013 at 03:26..
Reply With Quote
  #2  
Old Thu 07 November 2013, 14:15
danilom
Just call me: Danilo #64
 
Novi Sad
Serbia
AC-1 - This category applies to all AC loads where the power factor is more than 0.95. These are primarily non-inductive or slightly inductive loads, such as heating. Breaking the arc remains easy with minimal arcing and contact wear.

AC-3 - This category applies to squirrel cage motors with breaking during normal running of the motor.
On closing, the contactor makes the inrush current, which is about 5 to 7 times the rated full load current of the motor.
On opening, the contactor breaks the rated full load current of the motor.



So look at AC3 10-15Amps as the spindle should not pull more than 8 if its a single phase vfd.
Reply With Quote
  #3  
Old Fri 08 November 2013, 07:31
KenC
Just call me: Ken
 
Klang
Malaysia
The biggest strength of a VFD is low inrush current. It will only draw 1x max motor current thanks to the VFD ramping up the motor with frequency instead of current. hence AC1 good enuf, but no harm using AC3. The cost difference is negligible consider the total project cost.
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Contactor Questions Mrayhursh 60. Wiring & Cable Management 1 Mon 12 August 2013 17:13
Trouble with contactor garycdba 70. Control Systems 20 Mon 29 August 2011 16:35
Power Contactor Not Working Regnar Troubleshooting 28 Sat 10 April 2010 12:38
Contactor for 115V... salewis 70. Control Systems 3 Tue 10 November 2009 06:33
Selflatching relay/contactor Mike Richards 70. Control Systems 0 Sun 25 February 2007 15:20


All times are GMT -6. The time now is 17:29.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.