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Any electricians or do it yourselfers....questions on how to wire up 110V outlet w/ relay

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by JRHAWK9, Jun 15, 2014.

  1. JRHAWK9

    JRHAWK9 Member

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    I'm in the process of wiring up my Kuuma. I will be moving my existing flow-through humidifier (which is currently mounted on my LP furnace plenum) to the new hot air duct work downstream of the Kuuma, seeing I don't plan on having my furnace on much during winter now that I will have the Kuuma. The way it's currently wired is it only has power when the LP furnace's fan is on and I have a "humidifier only" outlet which is mounted to the LP furnace.

    I plan on doing things the same way with my Kuuma. I don't think it's a good idea to have the humidifier running when there is no air going through the duct, ie when the fan is not running. My question is what type of 24V/120V relay do I need to accomplish this and what do I use for the trigger....R or G?

    thanks!
    Last edited: Jun 15, 2014

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  2. Fred61

    Fred61 Minister of Fire

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    Just connect the humidifier motor to the blower motor so when power is applied to the blower you will also be powering up the humidifier.
  3. JRHAWK9

    JRHAWK9 Member

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    The blower motor has a low and high speed circuit though and I don't want to add more load to the dedicated 110V line. The install manual calls for a dedicated 110V line to be ran for the furnace. Plus the humidifier has a standard AC 3 prong plug and I don't really want to be cutting that all up. I'd rather use a 24V/120V relay to control new outlet from a separate source if it's possible.

    Looks like -THIS- may work, however I'd prefer a more hardwired method.
  4. Don2222

    Don2222 Minister of Fire

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  5. JRHAWK9

    JRHAWK9 Member

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    I don't need a double pole though, all I need is a SPDT if I'm going about things correctly.
  6. JRHAWK9

    JRHAWK9 Member

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  7. Don2222

    Don2222 Minister of Fire

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    You do not have to wire the other contact, but if you do it will handle twice the current and last twice as long!
  8. JRHAWK9

    JRHAWK9 Member

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    It will be powering just a little fan motor rated 0.58 amps :) I'm leaning towards -THIS- one. It should work for what I need it for.
  9. JRHAWK9

    JRHAWK9 Member

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    OK....back up....lol I was just informed the 24V thermostat connections won't work for what I need to do. So.......I need a 120V relay and not a 24V one.
  10. ewdudley

    ewdudley Minister of Fire

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    The RIB2421C you're looking at above has separate 24 VAC/DC and 120-277 VAC coils to choose from.
  11. JRHAWK9

    JRHAWK9 Member

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    When I read -SPEC SHEET- for that one it does appear to be the case, however, I'm then confused as to how I would wire it up. According to the -WIRING DIAGRAM-, the left side is the supply side which I would wire the supply 110V into along with the trigger lead (120V). Would this 120V trigger lead connect to the wht/blu which is labeled 24Vac/dc? This is where I was thinking it's for use only with a 24V ac/dc trigger. I would then use the common and NO on the load side.
  12. ewdudley

    ewdudley Minister of Fire

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    YOYO. You should probably hire someone local to wire it up for you.
  13. JRHAWK9

    JRHAWK9 Member

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    I'll admit, I'm new to AC current, done some with DC though. I'm willing to learn. Seeing my trigger is now 120V and not 24V, I know all I pretty much need is a standard SPNO 120V fan relay, which has 4 connections.
  14. JRHAWK9

    JRHAWK9 Member

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    OK, use this SPNO fan relay as an example.

    [​IMG]

    The 1 and 3 terminals are the coil and are what needs to be energized in order to close the switched 2 and 4 terminals to supply power to the outlet.

    I will have a total of 5 wires:
    - a hot (A) and common (B) on the supply side
    - a hot (C) and common (D) on the switched side going to the outlet I want switched
    - a 120V trigger lead coming from the energized control (E)


    Terminal 1 gets: E
    Terminal 3 gets: B+D
    Terminal 2 gets: C
    Terminal 4 gets: A


    Then obviously all the grounds get grounded appropriately.

    Is this correct?
    Last edited: Jun 16, 2014
  15. maple1

    maple1 Minister of Fire

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    Not sure if I'm fully understanding what you want to do, and the details of your humidifier wiring/controls, but my thought is:

    Terminals 2 & 4 = (C) & (D).
    Terminals 1 & 3 = (A) & (B).

    I don't know about that 5th wire though? What's your control? Can you just parallel the wires that go to your furnace fan for (C) & (D) switching? I think I'm not grasping something in what you're doing...
  16. JRHAWK9

    JRHAWK9 Member

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    I basically want to switch a regular household outlet on/off using a relay and a control. Forget about the humidifier for now, as it's just a standard household 110V 3 prong plug. I just want to use a switching relay and control wire to switch an outlet on/off based on whether the control wire is energized or not. This means I will have 2 wires in from the supply (hot and neutral) , two wires out to the switched outlet (hot and neutral) and my control wire. The 5th wire is the control and that will be coming from a 120V wire on the furnace which is only energized when the furnace fan is on.

    The basis of how I have it wired above I got from here:
    http://www.hvacquick.com/howtos/howto_relay.php
  17. maple1

    maple1 Minister of Fire

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    I think you need your 'control' wire ('hot'), and a common wire from the same circuit, going to 1 & 3, and terminals 2 & 4 in-line with the hot wire of your switched outlet. So that it connects/completes that wire circuit when the coil energizes. My relays only have 4 wires hooked to them - one pair for each circuit. Relays are designed to keep the circuits separate and just use one to switch the other - therefore I'm not understanding using 5 wires.
  18. JRHAWK9

    JRHAWK9 Member

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    This could very well be and you are probably right. All the relays I've ever done before have been DC, where I would have a dedicated single "trigger" wire.

    So.....I'd take the hot and neutral of the control circuit and wire them up to the coil on the relay (does it matter which one goes to 1 or 3 as long as they are connected to 1 and 3)? Then the hot from the supply side connects to 2 and the hot going to the outlet I want to switch will be going to 4 (again, can I reverse these two). The neutral from the supply side connects directly to the neutral on the outlet I want switched. Is this what you mean? I think we may be getting somewhere now.

    thanks for all the help! As you can probably tell, I'm in the very early learning stages of AC current.
  19. maple1

    maple1 Minister of Fire

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    Yes, I think that is what I mean.

    And no, it shouldn't matter.

    I just think of the coil side as a light receptacle (load), and the other side as a simple light switch. The first gets white & black hooked to it, the second interrupts the black or closes & opens it.

    I am no electrician though - so be forewarned. Just one of those DIY guys you mentioned.
  20. JRHAWK9

    JRHAWK9 Member

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    yep, that's how I made sense of it too after I read it. I plan on running it by an electrician I know to make sure.
  21. 700renegade

    700renegade Member

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    Unless I'm missing something from your original post, you have a problem yet.
    The Kuuma fan is two speed meaning you have two separate 'trigger' wires for the coil. What I see discussed above will only trigger when the Kuuma fan is on low ( or high ) but not both.

    since your humidifier is only 0.58A ( 70 watts ) this I how I'd do it. Use a 110V coil SPDT ( or DPDT whichever is easier to find ) and isolate the Kuuma low speed and high speed fan power using the relay. I can't imagine the tiny extra draw of 70 watts is going to matter to the Kumma controls. See the attached sketch

    Attached Files:

  22. JRHAWK9

    JRHAWK9 Member

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    I agree with you about the low/high fan issue. This is why I wouldn't be using them. Daryl mentioned I can use the black and yellow wires coming out of the button thermostat (low fan control) for my control. This is what I need to verify though to make sure this is the case. This is what he said:

    The wires he's referring to as "black & yellow" are as follows: The black is hot and is connected directly to the black 110V power feeding the unit. The yellow wire connects to the black wire on the back of the Honeywell fan relay (R8239A 1052).

    I have attached the wiring diagram and have the black and yellow wires mentioned above circled in red.

    Do you know if using these two wires to control the coil is correct?

    thanks!

    EDIT: Looking at the wiring diagram above as well as the one for the actual Honeywell fan relay (see link below), I think the low fan control (button thermostat) is nothing but a switch which switches the hot on/off to feed the fan relay. If this is the case, I would want to use the yellow coming out of the button thermostat to the coil and a neutral. If I used both the yellow and black then when the switch (button thermostat) closes I will have TWO hot wires going to the coil....that's a no-no! lol

    The way it looks to me is this: the button thermostat has a constant hot feeding it. Once the temperature reaches the set point (105) the switch closes, which then sends power to the yellow wire. This is connected to the black wire on the blower system which in turn powers the blower system.

    https://customer.honeywell.com/resources/Techlit/TechLitDocuments/60-0000s/60-2023.pdf

    Attached Files:

    Last edited: Jun 17, 2014
  23. JRHAWK9

    JRHAWK9 Member

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    OK, here's my crude sketch of how I currently have it wired. I plan on running it by an electrician I know as well as an HVAC guy. Comments?

    Kuuma Wiring.jpg
  24. 700renegade

    700renegade Member

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    Now that I see the diagram, you are going WAY overboard.
    Simply connect your outlet for your humidifier to the yellow wire downstream of the snap switch ( what you are calling a button thermostat ). You have a neutral in that 4x4x2 box that you can bring with for the neutral side.
  25. JRHAWK9

    JRHAWK9 Member

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    Yeah, that would work if I wanted to keep them on the same circuit. Instructions say they want a dedicated line ran to the furnace so I wanted to keep it dedicated, even though the humidifier hardly draws anything. Like you said, it's overkill, but I've already have it wired with the relay so it's pulling power from a different circuit. Was going through the additional work worth it for a measly less than an amp....probably not. Wouldn't be the first time someone told me something I did was overkill and probably won't be the last.

    Thanks for all the help! :)

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