3 Phase Motor - Fault Indicator

Discussion in 'General Electronics Chat' started by majsyd2010, Sep 18, 2010.

  1. majsyd2010

    Thread Starter Member

    Aug 29, 2010
    61
    1
    Good Day Guys …
    I must say that love this website and all these helpful forums.
    My question! Is there any way of creating an indication lamp if the motor lost its supply phase using really or contactor, For example Blue phase supply fuse blown to the motor, and if that happen, the fault light indicate.
    See what you guys come with
    Cheers
     
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,795
    951
    Current sensing relays are common in industrial applications. They sense the flow of current and either tell you it has stopped or when it has gone above or below a threshold.

    Implementing something to sense the current in the phases should be pretty straight forward. Are you looking for a commercial product to do this? Honeywell makes hundreds of models and types for AC or DC currents ranging from a single amp to thousands of amps. Both mechanical and solid state, open loop, or closed loop.

    Google current relay and look for honeywell, they have a multipage pdf outlining their product line.
     
    majsyd2010 likes this.
  3. majsyd2010

    Thread Starter Member

    Aug 29, 2010
    61
    1
    Thank you...
     
  4. timrobbins

    Active Member

    Aug 29, 2009
    318
    16
    I suggest a cheaper and simpler solution is a 'phase failure' relay - it is put across the motor input, and if a phase fuse fails, or a phase voltage drops below a certain relative percentage compared to the other phases, then it activates.

    Ciao, Tim
     
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  5. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Take a look at this ....... http://www.squared.com/us/products/relays_timers.nsf/unid/D19099054747188A85256CB60056D979/$file/phaselossrelays.htm
     
  6. timrobbins

    Active Member

    Aug 29, 2009
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  7. Pich

    Active Member

    Mar 11, 2008
    119
    4
    The easiest way would be to connect the lights across the fuses, of course lights would need to be the same voltage as the supply voltage.
     
  8. majsyd2010

    Thread Starter Member

    Aug 29, 2010
    61
    1
    Pich ... You give me the cheapest and easy way and belive it or not, I am doing it right now.

    I keep saying that love this forum .. Keep learning and learning
     
  9. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    Yea, and believe it or not good old panel mount Neon indicators are great for this. They usually come with an integral resistor for 120V but it's easy enough to add to that if your source is 408Y/277

    I personaly like the green ones but they'd be best on the load end of the fuses to neutral since they'd indicate all is OK, you'd probably want the orangish-red ones if you used them across a fuse to indicate a dropped phase.
     
  10. majsyd2010

    Thread Starter Member

    Aug 29, 2010
    61
    1
    I used the green last night and work perfectly great as what I want. I am keep say this that you gotta love this website. what a wonderful forum ....
     
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