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How to wire for 2 110V fans and a 110V circulation pump?

farmerwannabe
farmerwannabe Member Posts: 3
I am installing a corn mass boiler with 2 zones and have a dragon heat exchangers with 110V fans on each Zone. I also have a water circulation pump, 110V, on the boiler. My question is, how can I get each zone to operate independently when calling for heat, but have the circulation pump turn on when one or both of then call for heat?
I have not purchased any switching relays yet so I am open to anything. I have a few ideas, but I don't think they are right.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 18,923
    Assuming that whatever is turning on the fans is an SPST switch -- thermostat, wall switch, whatever -- you will need to wire a relay (be sure the load side can handle the pump) in parallel with each fan. Then on the load side, wire the NO contacts in parallel to the pump.

    Be sure everything is rated for the correct voltage and load -- and provide correct wire sizes and circuit breaker or fuse protection for the whole thing.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    farmerwannabe
  • Big Ed_4
    Big Ed_4 Member Posts: 1,882
    You need two double pole relays ,one for each zone and use one of the poles to activate the circulator . They make multi zone relays with end switches which can be used . What voltage thermostat will determine the relay to use ...
    I have enough experience to know , that I dont know it all
  • Zman
    Zman Member Posts: 7,328
    A zone valve on each zone with a zone controller managing the t-stat, zone valve, and circ would be one way to do it. You would wire the unit heater fan to a strap-on aquastat that will turn on the fan when the pipe gets hot.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • farmerwannabe
    farmerwannabe Member Posts: 3
    Jamie Hall: Thermostats/valves will be the switch, based on what your saying I believe my first thought might work... I get two of these and run the circuits out of them in parallel to the fan/circulation pump. https://www.supplyhouse.com/Taco-SR501-4-1-Zone-Switching-Relay . That was my first thought, but needed to confirm.
  • Zman
    Zman Member Posts: 7,328

    Jamie Hall: Thermostats/valves will be the switch, based on what your saying I believe my first thought might work... I get two of these and run the circuits out of them in parallel to the fan/circulation pump. https://www.supplyhouse.com/Taco-SR501-4-1-Zone-Switching-Relay . That was my first thought, but needed to confirm.

    One 2 zone model would work as well.
    You really don't want the fan blowing cold air on you, this is why running the fan off an aquastat is a common control strategy.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • farmerwannabe
    farmerwannabe Member Posts: 3
    Ok, that makes more sense with the aquastat, little more then I wanted to spend, but I see why now. Thank you all for your advice, I believe I can get this all wired up now and working as I want it.
  • HomerJSmith
    HomerJSmith Member Posts: 1,562
    edited July 2021
    I really don't have enough information to understand what you are trying to do.

    Where do you plan on controlling the fans from, I assume that you want to control each fan with a thermostat in the room that the fan is in.

    What is your source for the electricity for each fan and how far away are each fan from the boiler circulator?

    What you must be careful of is that the power source for the fans and circulator are on the same buss in the panel if the fans control the circulator directly. Each of the two busses on a panel carries 110V and they are 180 deg out of phase. That's how you get 220V and you don't want to send 220V to a 110V circulator.

    It's all about logistics which is what you are asking, but I don't know a lot about your situation.

    There are low voltage and high voltage methods of control.
  • GroundUp
    GroundUp Member Posts: 1,399
    Are these units in separate buildings from the boiler? Are there underground lines? What is the heat load of each zone? We really need more information to properly answer the question. Most biomass systems have a boiler circ which runs constantly and keeps the unit heaters always hot, then the fan is simply switched either with a line voltage thermostat or a 24v stat w/ relay.
  • Zman
    Zman Member Posts: 7,328
    edited August 2021
    Unit heaters give up ~10% of their rated output when you circulate hot water with no fan running. I like to turn off the water flow if possible.
    A device like this will do the job of the aquastat. I think close at 140 and open at 125 would work well. You could go higher if you need condensate protection for the boiler. http://senasys.com/product/2570f113-thermostat-switch
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    farmerwannabe
  • Dairon421
    Dairon421 Member Posts: 49
    I'll give you the best advice I can. My thoughts are you have two single pole relays to control the fans. Have two thermostats for each relay coil so when it's a call the contacts will close and send power to your fans. Now your fan circuit is done. Now i never heard of a boiler like that but what if you wire a 120v temperature control in series with the circulation pump. So whenever the boiler turns on it rise in temperature, the temperature switch close and will send power to your pump regardless of which zone come on.