little dilemma with relay

Discussion in 'The Projects Forum' started by Bigcountry, Aug 12, 2010.

  1. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
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    I can't seem to find a relay that will work on 220 VAC but close the contacts with 12 or 24 VDC. anyone have a good idea where I could find this at?

    To further explain it out I have a 220 VAC fan that I want to turn on and off via PLC. The voltage to open and close the contacts on the relay need to be VDC.

    thank you for helping me. I have been looking already and I haven't come up with anything yet.
     
  2. sceadwian

    New Member

    Jun 1, 2009
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    Try a solid state relay, you should easily be able to find one that can switch 220VAC at a few amps via nothing more than a 3V signal from a PLC. You need to know the current load to chose an appropriate relay. All that needs to be placed on the input (low side) from your PLC is a single resistor.


    I've found this as an example for a solid state zero cross 2amp relay that will turn on from an input signal as low as 1.2 volts at about 10ma, they're actually triggered by current(opto isolated triacs).
    http://search.digikey.com/scripts/D...k=hp_go_button&KeyWords=425-2409-5-ND&x=0&y=0

    Bellow is a link to the PDF
    http://media.digikey.com/pdf/Data%20Sheets/Sharp%20PDFs/S102T02,S202T02.pdf?cshift_ck=null&client_id=5042
     
  3. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
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  4. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    Yes. That should do fine. The one you would want is
    D3PF2AT which is a 24VDC coil.
     
  5. sceadwian

    New Member

    Jun 1, 2009
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    How can you say that windoze? He hasn't specified the number of amps it needs to carry.... And the one you selected in a 3PDT which hints at it being a polyphase motor? There's very little information in this thread and a lot of speculation.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    If you list the current requirements of the relay and if you want PCB mount or socket mounted. I can give you hundreds of relays capable of being switched from 12 vdc and can switch 250VAC at 10A or so.. No need for a solid state relay which is much more expensive.. A $2 pcb mount relay can easily fit the bill.
     
  7. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    605
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    Quite easy. He wants to run a fan. Admitedly he hasn't specified current requrements but it would have to be one hell of a fan to draw more than 12A which is what the relay is capable of. I feel if the fan is any bigger than this he shouldn't be playing with it.

    Its a relay. Only use 1 pole if its a 3 pole relay. I am not quite sure how you determine its a polyphase motor from the choice of relay. The OP asked if this relay would do the job. So long as the motor doesn't draw more than 12A then yes it will.

    As mcgyvr has stated there are also thousands of relays out there that will do the job. I just answered the OPs question with the info he supplied.
     
  8. sceadwian

    New Member

    Jun 1, 2009
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    Yes, but what about smaller? What if the fan only draws 1/2 to 2 amps, you're prescribing a device overrated by 600% =) Sure it'd work for a lower amperage fan but even someone being cautious with overrating that's a bit much without knowledge o the exact application.

    I didn't determine that it's 3 phase powered, just speculated because it's capable of 3 position dual throw operation. My point was that these are all completely blind stabs in the dark without additional information from the poster.
     
  9. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
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    I will have to tell everyone I am sorry. I just got tunnel vision and had other things on my mind.

    Here are the specs of the fan

    220V 50 Hz 130 Watt .5 amps the number of cycles is 1400.

    It is rough being an American in Europe. The fan I have is from Turkey. It works pretty good for the project I am doing.

    I was just using the one I pick has an example because of the connectors I can run my wires too.

    Thanks everyone for their input.
     
  10. sceadwian

    New Member

    Jun 1, 2009
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    number of cycles is 1400 per what, second, minute, hour, day, week, month, year?
     
  11. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    They sell SSRs everywhere and they're ideal for a lot of situations due to the wide control voltage range they'll accept at very low control current requirements. You can even pick them up with a 30A contact capacity from some eBay sellers for as little as $15 + a heat sink.
     
  12. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
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  13. sceadwian

    New Member

    Jun 1, 2009
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    Good luck Big Country, if you run into problems, ask again =)
     
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