Quick help on relay connection please

Discussion in 'General Electronics Chat' started by Nate_Bro, Apr 20, 2011.

  1. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    I got this relay from radioshack and I'm not sure how to hook it up...

    http://www.radioshack.com/product/index.jsp?productId=2049721&retainProdsInSession=1

    its the tyco 125VAC/10A DPDT Plug-In Relay
    Coil rating of 125VAC, 15mA, 4.5 ohms

    I have used many Bosh 4 pin automotive relays before, but since this will control a pump on AC I wanted to do it right.

    I looked at this image, but not sure about the A and B poles...
    do I need a Diode or resistor?
    [​IMG]


    this is the circuit I have, but I used the automotive relay the first go around...
    [​IMG]
    now I just need to figure out how to wire this AC relay in there!

    thanks for your help!
     
  2. madmantrapper

    New Member

    Apr 20, 2011
    15
    0
    I'm not sure what you are after. Are you trying to use the AC coil to turn on the AC pump with a battery. AC coil will not work with DC.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    You also need a DC coil that is rated for 12 VDC.
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,771
    929
    As your wiring diagram shows, 'A' and 'B' are the relay coil connections. The relay is an AC type, meaning it needs 120VAC to energize the coil.

    Automotive relays use 12 volt DC to energize the coils.

    Be very careful using mains AC power. Unless you want your DC battery and LED's to melt down, you must ensure that the connections are correct. If the diagram is the same circuit you used with an automotive type relay, then it will not work with an AC powered relay.
     
  5. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    Ya I was using DC power with the other relay, now I have to change to AC....

    do I just wire in 120V direct from the wall to the A and B switching poles?

    I was going to get a 12V relay but someone on another forum said I had to get a 120V relay, so now I have one, and I can't use it, I also tried returning it, but they will not take it back...

    so I'm stuck with a $9 relay I have no idea how to use, and the person that told me to get it will not answer my posts...

    do I wire 120V positive to the A pole, and negative to the B pole or the other way around, or do I need a transformer?
     
  6. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    as your diagram is wired it is difficult to believe the relay will energize when the float switch closes. There will be substantial voltage drop across the green led and 200 ohm resistor.
    Not sure what the yellow led is being used for. assuming is being used for battery condition or 12 volt power on indicator.
    If the green led is being used to signify the pump is on, better to wire the way I have reworked your schematic.

    [​IMG]
     
    Last edited: Apr 20, 2011
  7. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    that makes sense, thanks!

    lets just say for now I only want to get the relay to open and close, where do I hook up the wires?

    I know how to hook up the pump wires and all that, but have not figured out how to activate this relay yet....
     
  8. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    What is the rating on your float switch? Can it handle 120VAC?
     
  9. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    no but I can work around that (get another switch or do something else)

    I'm just trying to get the relay to open and close right now haha

    thanks!
     
  10. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    you will have to energize your relay with 120 volts AC
    use appropriate bulbs instead of LEDs

    try this:
    [​IMG]
     
    Nate_Bro likes this.
  11. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    Warning:
    Remember to not let more than 10 amps run through your relay!
    Be sure of the amp draw of the pump when under full load. The information should be on the pump motor.
     
  12. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    There you go!!!!!!!


    thanks so much everyone!!!!!
     
  13. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    the pump runs max at 0.3 amps :D

    its a very small pump
     
  14. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    Just wanted to say thanks again, and I checked my float and its rated for 240VAC and has a 0.3amp max, so I could use it directly, but I'm going to use the relay just to make things safe.

    also on poles 3 & 5 can I use my DC power to switch on the green LED??? or are all the poles linked to the AC side?

    Would this circuit work ok?

    [​IMG]
     
    Last edited: Apr 21, 2011
  15. Adjuster

    Well-Known Member

    Dec 26, 2010
    2,147
    300
    And just as crucially, are you sure the switch and the wiring connecting it have sufficiently waterproof insulation for this to be safe? Mains electricity and water can be a lethal combination.
     
  16. Nate_Bro

    Thread Starter New Member

    Mar 2, 2011
    18
    0
    "are you sure the switch and the wiring connecting it have sufficiently waterproof insulation for this to be safe?" = YES!

    also this circuit is a flood detector, so hopefully it never has to engage...

    if this circuit goes off i'll have a lot more to worry about then this circuits waterproof insulation...
     
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