Hi Amp Relay Help..

Discussion in 'General Electronics Chat' started by sharkeys_2k, Jul 19, 2010.

  1. sharkeys_2k

    Thread Starter New Member

    Jul 19, 2010
    3
    0
    Hi,

    i need to use a relay to switch 12v supply but it will need to cope with upto 200amp, im havign trouble finding a single relay that can cope with this, my question is could i use for example 2x100amp relays to share the current or 4x50amp ect ect?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    A starter solenoid should be adequate for that load. Prices seem to be in the $20 range.
     
  3. sharkeys_2k

    Thread Starter New Member

    Jul 19, 2010
    3
    0
    im in the UK and all the starter selonoids i can get hold of are only 100amp.......can you use the idea i suggested or have i got this completly wrong?
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  5. sharkeys_2k

    Thread Starter New Member

    Jul 19, 2010
    3
    0
    they seem very expensive but sound like what i need..........thanks

    just out of curiousity is it possiable to share the load over relays?
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    I wouldn't recommend sharing the load over relays (neither does UL or any other safety agencies although I have heard of situations where the accept that construction)

    And Albrights contactors really aren't that expensive... You should be able to get one in the $20-30 USD range.
    I really like their latching coil versions so you aren't creating heat keeping the coil energized all the time but it does require different circuitry.
     
  7. timrobbins

    Active Member

    Aug 29, 2009
    318
    16
    I concur mcgyvr - albright has a good commercial range - you just have to select the appropriate one for the job at hand.

    Sharkey, what is your application? Can you control the current through the relay by say only allowing substantial current flow when the relay is on (and not switching). If the number of switchings required is minimal, and you want a quick fix then you should be able to get away with parallel contacts, and even under-rated contacts, especially if load isn't inductive or incandescent - it comes down to contact wear and heating and reliability.

    Ciao, Tim
     
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