Couple questions

[RobsPCing]

This is a very informative site, all except the wiring of the thermostat. I spent 1 1/2 hours the other night messin around with this thing. So now all im askin of you guys is if i show you a picture of the thermostat im workin with, do you think you can tell me how to wire it? I was'nt going to use a contactor but now i am. http://www.powdercoatoven.4t.com/Control%20box.html This is the how i want it to be wired up if possible. Thanks for all your help, Rob.

[JTW37]

If you look back through the past post, you can find a couple of wiring schematics. The only difference I have found is in the controller. Some are from the oven scavenged from, some are digital with 10 (like mine) and 12 connections. Once you see the main wiring schematic the rest isn't to bad.

I plan on adding some fusses in my circuit, to protect against any mislead electrical current.

[RobsPCing]

Heres the left and bottom side of the thermostat that im trying to use.

[RobsPCing]

Heres the right side.

[gourdhedd]

Rob, I'm assuming that you're using a regular kitchen oven t-stat. This thing is really just and ON/OFF switch. When certain temperatures are exceeded at the thermocouple, the switch is OFF. When the temperatures are below the set temp, the switch if ON.

Set the t-stat dial to OFF and take a volt-ohm meter and check continuity between all of the contacts, writing down your results. Now, set the temp dial to about 150deg and check the continuity between all contacts again. Shouldn't be much difference. Now dip the thermocouple in a pot of boiling water, let it sit for a minute or so, and check the continuity again. You should have a set of contacts that that are different from the previous setting, that is, they should be open or OFF. These contacts controlled the oven element and now will control your contactor coil in your oven.

Remember, if temperature of thermocouple is at or above the setpoint, contacts will be open (element OFF). If below setpoint, contacts will be closed (element ON).

[RobsPCing]

Ok so here is what i got. I dont know if what you meant as a little difference was from .1 to .4 ohms or not, but thats the only thing that changed. I kinda drew up a rough figuration of what i got. Let me know what you think.

[gourdhedd]

After studying your diagrams a bit, I believe that your thermostat may not be calibrated properly. Since contacts 1-3 and 6-7 turn on when you set the dial to 150, it would seem that these are the ones you're looking for. Turn the temp setting down just a bit, or increase the heat on the thermocouple. You may need to put the thermocouple over an open flame for a short time. If 1-3 and/or 6-7 become open (element OFF) with the addtional heat, either one of them will work to cycle the contactor.

The variance in ohms is of no consequence. Either .1 or .4 is a small amount of resistance, and that's what you want through a switch, low resistance.

[RobsPCing]

You are the man Gary!! 1 and 3 Click off when its over and open flame and i read off on my ohm meter when it clicks. So now the next question is how do i wire it up to my contactor? And in your wire box is your on/off swith just a regular 110v 2 pole switch? It's starting to make sence alot more now.

[gourdhedd]

Originally Posted by RobsPCing

So now the next question is how do i wire it up to my contactor? And in your wire box is your on/off swith just a regular 110v 2 pole switch? It's starting to make sence alot more now.

Connect a wire from one of the incoming 110v lines, route it through the switch (yes, just a regular light switch), through the contacts on the t-stat, and then to one of the coil contacts on the contactor. The other coil contact gets wired back to the neutral. Turn on the switch, set your temp, and the thermostat will cycle the contactor thus turning your elements on and off. This assumes that you have a 110v coil on your contactor.

[RobsPCing]

Originally Posted by gourdhedd

Connect a wire from one of the incoming 110v lines, route it through the switch (yes, just a regular light switch), through the contacts on the t-stat, and then to one of the coil contacts on the contactor. The other coil contact gets wired back to the neutral. Turn on the switch, set your temp, and the thermostat will cycle the contactor thus turning your elements on and off. This assumes that you have a 110v coil on your contactor.

Does it matter if its a 110 or 220 coil on it?