Shiva

Discussion in 'General Electronics Chat' started by sbhaskar, May 27, 2010.

  1. sbhaskar

    Thread Starter New Member

    May 27, 2010
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    I need to connect a 240V single phase pump to the relay. The purpose is when there is power failure and the power comes back the pump shouldn't turn on. My relay will be designed with on/off switch and a reset switch. I was able to do for the 120v pump with DPST relays and switch.
    But I caught confused with 240V. Can anyone suggest how can this be done.

    --Thanks
    --Shiva
    :confused:
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    You are messing with mains voltage.
    State your experience first.
     
  3. sbhaskar

    Thread Starter New Member

    May 27, 2010
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    0
    This what I did to connect the 120v pump to the reset switch
    I connected the reset switch, on/off switch to the DPST relay. So when I turn on the on/off switch the pump will not turn on unless I reset the switch. So if there is power failure and the power comes the on/off switch will stay on, but the pump will not turn on, unless I manually reset the reset switch. The reason I do is this because the I am using the cryo pump. This cryo pump has to turned on only when the pressure is below 100mTorr. So if there is power failure the chamber pressure will reach to atmospheric and I dont want the pump to start at atmospheric.

    I was able to do successfully with 120V pump.

    Now I have to do the same thing with 240V pump.
    What I am thinking is I will have DPST on/off switch, DPST reset switch, so two main hot wires will be connected to the switch. My confusion is how to connect the relays.Also what type of relay should I need.

    I have one idea- I will test with two DPST 120V relays connected with two sperate hot wires.
    Since its 240V, I am little bit hesistant to test it.So before I do just want to clarify , is there any other way should I need to do.

    --thanks
    --Shiva
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    Don't explain....post ur diagram so we can see
    second.. tell me what experience you have in fiddling with high voltage
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    It is quite easy to do this. You need one relay with at least 2 contacts and two push buttons (on/off). The on button has to be normaly open, and the off button normaly closed.
    But post your schematics so we can take a look
     
  6. sbhaskar

    Thread Starter New Member

    May 27, 2010
    3
    0
    Do to 240V. I used two 120V DPST and used the reset switch to power up my pump. It worked fine.
    I was thinking to use single 240V relay which seems to confusing for me. But anyways it worked with two 120V DPST.

    Thanks for allowing me to post my queries.

    --Shiva