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Author Topic: Wiring a thermostat  (Read 2905 times)

Offline opus

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Wiring a thermostat
« on: March 28, 2012, 03:39:55 PM »
You know, just one of your normal bi-metalic ones you might have in your home.  Its got 2 leads on it.  I want to wire it into a fan to come on at a certain temp.  I assume I cant run 5A through it so I would have to use a relay to run it? 
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Offline chev49

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Re: Wiring a thermostat
« Reply #1 on: March 28, 2012, 03:47:24 PM »
i haven't tried to do that... but i would think one of those car relays for security systems, etc would work just fine. they can be bought on eBay cheap for 10 at a time..

Thanks for the idea...will try that also, as i have lots of the relays, and some thermostats...
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Offline baker4106

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Re: Wiring a thermostat
« Reply #2 on: March 28, 2012, 08:39:30 PM »
You are right, don't try to run 5A.   I purchased a relay at a locale auto parts store to run mine and it works fine.

Offline mikke60

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Re: Wiring a thermostat
« Reply #3 on: March 28, 2012, 08:47:54 PM »
you can also buy a thermostat intended for use with electric baseboard.Can handle plenty of amps.mike

Offline Jriddle

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Re: Wiring a thermostat
« Reply #4 on: March 28, 2012, 09:17:15 PM »
you can also buy a thermostat intended for use with electric baseboard.Can handle plenty of amps.mike

This is what I did. I run 12v for the fan through them seems to work great for me.

John
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John Riddle
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Offline opus

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« Last Edit: March 29, 2012, 04:29:00 AM by opus »
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Offline Jriddle

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Re: Wiring a thermostat
« Reply #6 on: March 29, 2012, 01:24:12 PM »
I would go with the first model. The second may not support the amp draw that you may need.

John
If It Can't Be Grown Then It Has To Be Mined
John Riddle
Wells NV
1984 MC9

Offline mikelcan

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Re: Wiring a thermostat
« Reply #7 on: March 29, 2012, 03:15:15 PM »
 I would think that a heating thermostat would work opposite of what you desire.  They are designed to turn something on when the temperature drops below a set point.  For a fan you would want an AC or attic fan thermostat that will turn the fan on when the temperature is above a set point.  I would think that this would work:
http://www.ebay.com/itm/Attic-Fan-Thermostat-120-240VAC-Model-1A22-7-New-/120743373884?pt=LH_DefaultDomain_0&hash=item1c1cddac3c#ht_793wt_1112

Mike

Offline Jriddle

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Re: Wiring a thermostat
« Reply #8 on: March 29, 2012, 03:21:06 PM »
I would think that a heating thermostat would work opposite of what you desire.  They are designed to turn something on when the temperature drops below a set point.  For a fan you would want an AC or attic fan thermostat that will turn the fan on when the temperature is above a set point.  I would think that this would work:
http://www.ebay.com/itm/Attic-Fan-Thermostat-120-240VAC-Model-1A22-7-New-/120743373884?pt=LH_DefaultDomain_0&hash=item1c1cddac3c#ht_793wt_1112

Mike

True
Depending on the use of thermostat I assumed he wanted to turn on a fan in a heat exchange.
Good Point

John
If It Can't Be Grown Then It Has To Be Mined
John Riddle
Wells NV
1984 MC9

Offline opus

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Re: Wiring a thermostat
« Reply #9 on: March 29, 2012, 03:50:08 PM »
Sorry, I want the fans on the heat exchanger to turn on at 67 or whatever.  No AC involved.  I should have clarified.
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Offline opus

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Re: Wiring a thermostat
« Reply #10 on: March 29, 2012, 09:51:47 PM »
Will the Honeywell work with just 12V?  I see it is rated for 120/240.  I dont suppose the voltage would really matter, would it?
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Offline Jriddle

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Re: Wiring a thermostat
« Reply #11 on: March 30, 2012, 12:31:17 AM »
Will the Honeywell work with just 12V?  I see it is rated for 120/240.  I don't suppose the voltage would really matter, would it?

Yep pretty much what I have.

John
If It Can't Be Grown Then It Has To Be Mined
John Riddle
Wells NV
1984 MC9

Offline belfert

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Re: Wiring a thermostat
« Reply #12 on: March 30, 2012, 12:51:52 AM »
A simple bi-metal thermostat really shouldn't care about voltage.  Some fancier thermostats might need power from the furnace, but many of them work on batteries these days.

I had bought some dead simple bi-metal thermostats, but they turned out to be junk.  The quality was terrible and the setting wouldn't stay were it was was set.  I bought some $15 digital thermostats instead that have batteries.  I have yet to try them.
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Offline opus

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Re: Wiring a thermostat
« Reply #13 on: March 30, 2012, 12:56:18 AM »
Ok, I will grab a couple of those Honeywell stats.  This way I can run the power right to it and not have to deal with relays.
1995 BB All-American - A Transformation.