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Relay for pumps

  • 29-11-2009 9:57pm
    #1
    ellamuffin
    Registered Users, Registered Users 2 Posts: 5 ✭


    Hello,
    I have a heating system that uses 3 pumps. say A,B & C

    I need A & B to be on when the boiler is on but when the back boiler reaches a certain temperature and its thermostat kicks in I need B & C to turn on and A to turn off. At the moment Iam physiclly turning them off and on as reqired. I believe a relay is the best way to go. :confused:

    If so could somebody recommend a model and distibutor and are they easily wired up.


Comments

  • #2
    2011
    Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,641 Mod ✭✭✭✭2011


    Hager make good DP contactors with normally open and normally closed connections. You can buy them in Kellighers, EWL, Eastern Electrical and Eurosales. They are din rail mountable and rated at 10A, which would be fine for the average circulation pump.


  • #3
    ellamuffin
    Registered Users, Registered Users 2 Posts: 5 ✭ellamuffin


    Hi 2011,
    Is there supposed to be an image there?? Im not seeing anyting but an x in a box!!:o


  • #4
    2011
    Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,641 Mod ✭✭✭✭2011


    Sorry, I could not do images on the iPhone!! 


  • #5
    ellamuffin
    Registered Users, Registered Users 2 Posts: 5 ✭ellamuffin


    Thank you for your reply.
    This is just for a home set up. Would this suit. :confused:
    What i have at the moment is when the i turn on my boiler this turns on the power to pump A and B. Then when i turn on the stove and the thermistat reaches 40 degrees it turns on pump C. So I go out and turn off the boiler Pump A, these are all 240 V switches.
    Hope this makes sense.
    So is it not a relay that i require ?

    Thank you


  • #6
    Bull76
    Registered Users, Registered Users 2 Posts: 289 ✭✭Bull76


    Hi,

    Your idea of the relay is okay as long as it is rated high enough for the load in question. The contactor is more robust and probably better suited to the task in hand.
    To know for sure you need to know what the load for each motor that needs to be switched On/Off.
    You just need to use the Thermostat for the back boiler to switch B Off and C ON. I'm assuming your Using the Back boiler to heat radiators down stairs and the thermostat is used to turn the pump ON to circulate the hot water to the radiators. Are you using a high and low thermostat arrangement or simple one thermostat? Only reason for the question is you could be cycling the pump power very often with only one thermostat unless you have some form of timer or latching mechanism in mind.
    So the Thermostat controls the Relay or Contactor. Then NC connections to Pump B and NO connections to Pump C. If your using the Relay you'd be switching the Live and leave permenant Neutral to the Pumps. With the Contactor you could switch both live and neutral.
    Hope it's helped or probably raised more questions.


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