Turn off Mains power when temperature is met

Discussion in 'General Electronics Chat' started by Guest3123, Feb 14, 2016.

  1. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    Just wondering.. Is there a device that will turn off AC Power when the set tempature is met?

    I know there's a thing called a thermostat, but does a thermostat control AC Power?

    I found something on Amazon, it's called, Lux WIN100 Heating & Cooling Programmable Outlet Thermostat.

    I'm pretty sure it doesn't handle 1.5kW though.
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    Thermostats are supplied by a transformer that reduces the line voltage to maybe 24VAC. In a gas furnace the fan is an AC Fan. I believe, in an electric furnace both the fan and the heating element are AC powered. I'm not sure if there is a transformer between line and heating element.
     
  3. Guest3123

    Thread Starter Member

    Oct 28, 2014
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  4. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    Ok, I was wrong.. Someone in the commets posted about it..

    "I have some experience with this. I have a 1000W (low) to 1500W (high) ceramic heater plugged into this unit and have had no issues with it running through two prongs compared to three."

    So I guess it can do what I want. So basically, I answered my own question, but other people can comment on this post if they want.
     
  5. Papabravo

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    Feb 24, 2006
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    Last edited: Feb 14, 2016
  6. Guest3123

    Thread Starter Member

    Oct 28, 2014
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  7. Guest3123

    Thread Starter Member

    Oct 28, 2014
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  8. Papabravo

    Expert

    Feb 24, 2006
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    The "round" thermostat is made by Honeywell. I'd suggest you look for a datasheet or an installer's guide for starters.
     
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  9. #12

    Expert

    Nov 30, 2010
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    The same way he did it. Get a 24 vac transformer, connect one 24V lead to 'R' in the thermostat. Connect 'W' to one side of the relay coil and the other side of the relay coil to the left-over wire on the 24 VAC. Connect the power voltage through the normally open contacts of the relay.

    That's a Honeywell T-86.
    It's getting hard to find good old stupid thermostats. Bi-metal or mercury bulbs cost more than microprocessors, so everything seems to have a microprocessor in it. After a couple of hours or reading, you might find you need to use to the R and W terminals to make a heating thermostat out of it.:rolleyes: While you're at it, remember to figure out how to give the thermostat a power supply. A few more hours of reading the spec sheet should tell you how.:p
     
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  10. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    Where can I purchase a 120vac to 24vac transformer?
     
  11. tranzz4md

    Member

    Apr 10, 2015
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    Of course perhaps you don't really wish to make as big a project out of it as possible. There are many types of thermostats including so-called line voltage thermostats readily available. Typically these are made with bi metal type contact In them and they can easily carry 1000 or 2000 watts. Just buy the right size. Unlike an earlier answer might lead you to believe, there are probably more installed and operating line voltage style thermostats on electrical equipment then all the Honeywell round thermostats ever made.
     
  12. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    Can you show me one wich will handle 1500 to 2000 watts, at 120/115vac ?
     
  13. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    Is this a good Transformer?

    Click here : Mouser Electronics

    That will handle 2000 watts?

    Also, here's a link for any future reader, if they want.. Here's the link for the Transformers page on Mouser Electronics. RIGHT HERE
     
    Last edited: Feb 15, 2016
  14. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    and is this a decent relay for switching 120vac 15A ?

    http://www.mouser.com/ProductDetail...=sGAEpiMZZMtSzCF3XBhmW6pLttCQF6lxaLqc0UVqVPM=

    Also here's a link for the relays : Right Here
     
    Last edited: Feb 15, 2016
  15. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    These are what I need, for a relay... Right..?

    http://www.mouser.com/Electromechanical/Relays/General-Purpose-Relays/_/N-5g36?P=1z0z2x8Z1yym2d8Z1yxtnyqZ1yzmjp4Z1yznet9Z1yv2wq6Z1yzmqz5Z1yim1t3Z1z0x36iZ1z0x3yyZ1z0x3ba&Ns=Contact Current Rating|1

    The Coil voltage is the voltage for the input.. The Thermostat will be the Input.
    The Switching voltage is the voltage for the load to be switched, like say a 120vac outlet.
    The Contact current rating, is the current it can handle.. So if I wanted to switch 1500 Watts, then I'd need a contact current rating of at least 1500watts / 120vac = 12.5 Amps.

    So I'd need at least 12.5 amps, let's just go for 15 Amps to be safe.

    So I found this one as well.
    http://www.mouser.com/ProductDetail...=sGAEpiMZZMtSzCF3XBhmW6pLttCQF6lxaLqc0UVqVPM=

    That's good right? It's a little expensive.. seeing that the only other one that they have is 20 on order, which really sucks because it's almost 3 times cheaper.
     
  16. Guest3123

    Thread Starter Member

    Oct 28, 2014
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    I honestly don't know if I got this right, but here's what I got so far..
    Hunted000647.jpg
     
  17. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Looks like you're missing a contact on the relay. There should be a common connection on the contacts side, which should be wired to the 120VAC main line.
     
  18. pilko

    Active Member

    Dec 8, 2008
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  19. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    This is what I mean...
    Untitled.png
     
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  20. #12

    Expert

    Nov 30, 2010
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    If it's that difficult for you to connect one transformer, one thermostat switch, and one relay, you shouldn't be playing with electricity. Buy the baseboard heater thermostat with a baseboard heater wrapped around it and quit trying to see if you can die in a house fire.
     
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