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HVAC problem-new(pic)

phillipphillip Member Posts: 2,948
edited August 2007 in General Discussion
[img][/img]scan0006.jpgOK, My t-stat and trnsfmr were crap.I found a new t-stat,A ritetemp model # 8095.I found out that the RH and the W terminals are the contacts.However the C terminal,Appears to be power for the t-stat.How can you provide power to something with only one leg?This is the new diagram Ive come up with.How the heck do I power the t-stat?

Comments

  • Marc1301Marc1301 Member Posts: 31,814 ✭✭✭
    edited November -1
    You now have T-stat meant for heat only, where the contacts close on temperature drop.
    What are you trying to do, heat, or cool?
    I presume cool, as it is only a fan you have described,......if that is the case, you bought the wrong t-stat.
    If you would like to e-mail me, feel free, but it may be a day or so before I get back to you.
    You are making a simple project into a complicated one.[:(]
    "Beam me up Scotty, there's no intelligent life down here." - William Shatner
  • D1D1 Member Posts: 11,412
    edited November -1
    R or RH - HEATER TRANSFORMER
    W - HEATING CONTROL
    G - FAN RELAY
    C - 24 VAC COMMON (optional)*
    Y - COOLING COMPRESSOR
    RC - COOLING TRANSFORMER
    O - DAMPER OR CHANGEOVER VALVE (POWERED IN COOL)
    B - DAMPER OR CHANGEOVER VALVE (POWERED IN HEAT)

    * The optional C-wire should be connected if available, it will extend your battery life significantly.
  • fishkiller41fishkiller41 Member Posts: 50,608
    edited November -1
    quote:Originally posted by Marc1301
    You now have T-stat meant for heat only, where the contacts close on temperature drop.
    What are you trying to do, heat, or cool?
    I presume cool, as it is only a fan you have described,......if that is the case, you bought the wrong t-stat.
    If you would like to e-mail me, feel free, but it may be a day or so before I get back to you.
    You are making a simple project into a complicated one.[:(]
    Marc nailed it.... U shouldda looked at the packaging your 'stat came in,. Or called a professional....

    Jeff
  • phillipphillip Member Posts: 2,948
    edited November -1
    the contacts open when its turned down to say 70.When i increase the temp ,the contacts close.Thats what i want to happen right?
  • phillipphillip Member Posts: 2,948
    edited November -1
    quote:Originally posted by fishkiller41
    quote:Originally posted by Marc1301
    You now have T-stat meant for heat only, where the contacts close on temperature drop.
    What are you trying to do, heat, or cool?
    I presume cool, as it is only a fan you have described,......if that is the case, you bought the wrong t-stat.
    If you would like to e-mail me, feel free, but it may be a day or so before I get back to you.
    You are making a simple project into a complicated one.[:(]
    Marc nailed it.... U shouldda looked at the packaging your 'stat came in,. Or called a professional....

    Jeff


    This is a project,Not a job.The t-stat was some stuff pops had in the junk bin.I realize that I could buy this device But like I said...Its a project[:)]
  • phillipphillip Member Posts: 2,948
    edited November -1
    So a cooling t-stat is needed,Not a heating?
  • Marc1301Marc1301 Member Posts: 31,814 ✭✭✭
    edited November -1
    Are you trying to run the fan to "cool" something by air circulation?
    Answer that simple question.
    If that is true,........as I presume with a fan only, you have the wrong t-stat.
    Unless you are going to put the fan in behind a heater!
    "Beam me up Scotty, there's no intelligent life down here." - William Shatner
  • Marc1301Marc1301 Member Posts: 31,814 ✭✭✭
    edited November -1
    quote:Originally posted by phillip
    the contacts open when its turned down to say 70.When i increase the temp ,the contacts close.Thats what i want to happen right?

    What you are describing above, is if you want to "raise" the temp, which a fan only cannot do!
    After reading all of this confusion, I would HIGHLY recommend, hiring someone to do this simple "project" for you!
    No offense meant BTW[8D]
    "Beam me up Scotty, there's no intelligent life down here." - William Shatner
  • phillipphillip Member Posts: 2,948
    edited November -1
    Thanks for your time.
  • Tailgunner1954Tailgunner1954 Member Posts: 7,815
    edited November -1
    Do you have a DT (double throw) relay, or only a ST (single throw)?
    If you have a 24vac (coil voltage) DT type relay, you could put your fan across the Com & NC contacts. When the T-stat is calling for heat (temp below set point) the relay will turn on, opening the fan power line. When the T-stat is above the set point (not calling for heat) the relay will turn off, closing the fan power line.
    If you only have a ST type relay, than you will need to get a T-stat that closes ABOVE the set point (IE: a cooling style T-stat).

    BTW, relays are cheaper than thermostats, if $$$ are a issue.

    On a 9 pin "ice cube" style DPDT relay, the coil leads are pins 2 & 8, pins 1 & 9 are common, pins 3 is NO to pin 1 and pin 4 is NC to pin 1 (I can't remember what the designation for # 5&6 is off the top of my head). To do what you have drawn, your fan would use pins 1 & 3, while my suggestion would use pins 1 & 4.
  • joeaf1911a1joeaf1911a1 Member Posts: 3,340
    edited November -1
    I cant figure out why you dont stick to just one voltage and forget about using a relay. This small fan should not draw much amperage that
    a decent thermostat couldnt handle.
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