how to build a reverse power relay??

Discussion in 'The Projects Forum' started by whitearrow, Jan 12, 2009.

  1. whitearrow

    Thread Starter Member

    Jan 6, 2009
    13
    0
    hi can anyone help me in building a reverse power relay for a 3 phase motor?? the voltage applied to it is 40V 50Hz. has any one got a simple circuit?? what ic's must i use to begin with??
     
    Last edited: Jan 12, 2009
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    To reverse a 3 phase motor, you have to swap two phases. The procedure is to open the main contactor and then use another two pole double throw relay to do the phase reversal. It's also a good idea to wait for the motor to stop turning before starting in reverse.
     
  3. whitearrow

    Thread Starter Member

    Jan 6, 2009
    13
    0
    i'am sorry, the reverse power relay is needed for a 3 phase 40V 50Hz generator not a motor. it is used to prevent from motoring.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    That puts me out of my depth - someone should be able to make suggestions, though.
     
  5. leftyretro

    Active Member

    Nov 25, 2008
    394
    2
  6. floomdoggle

    Senior Member

    Sep 1, 2008
    217
    2
    Hey Whitearrow,
    Tou probably need a diode between the generator and power supply.
    Explain a little bit more and these guys can help.
    Dan
     
  7. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    Reverse power protection is nearly standard on all generators.

    As leftyretro has said, you'll need to buy one if one is not fitted on the generator. It is quite expensive though.
     
  8. whitearrow

    Thread Starter Member

    Jan 6, 2009
    13
    0
    the problem is that i have to do this reverse power relay myself and i don't know exactly what parameters to measure to do this.
     
Loading...