Converting a burnout oven for HT

[Phil Dwyer]

Hi Friends,

I just got a jeweler's burnout oven from Stacy to use in some high school classes I teach. Of course, I want to use it for doing some heat treating as well. It has a built in pyrometer with manual dial control. I'm wondering if the stuff listed below, from another thread, is what I need. Also, just how would it interface with the kiln? Where does the kiln plug in/get it's power? Would I hack of the plug and wire the furnace into the SSR? Does the SSR get it's power from the PID?

Thanks y'all! (This is a seemingly endless journey and adventure!!)

All the best, Phil

This is the thermocouple you want
http://auberins.com/index.php?main_page=product_info&cPath=3&products_id=39

This is the pid if you want simple and to just read temp. It can also control a SSR if you wanted to contro electricity for a oven or say a valve for fuel supply.
http://auberins.com/index.php?main_page=product_info&cPath=1&products_id=14

This is the SSR you want for a electric oven.
http://auberins.com/index.php?main_page=product_info&cPath=2&products_id=30

To read temp you would just connect 110v to the pid and the thermocouple to the pid. The pid comes with directions. If you used the sample wiring diagram and never hooked in a SSR as it shows you would be reading temps as soon as you plugged it in. Wouldn't even have to program. It comes programed for type K. Get it and I will walk you thru on the phone if nessecary. I have two of them and unlimited long distance.

Here's a pic of the little burnout furnace...

 

[Phil Dwyer]

I emailed Stacy with this question. Here's what he had to say.

Bladsmth: [FONT=&quot]If you want to run an oven (or any similar AC device) from a PID controller, just hook a type K thermocouple to the PID , and a SSR to the PID. Connect the oven power cord to the SSR. When the PID cycles on, the power flows to the coils.Those burnout ovens are pretty slow moving and don't climb/fall very fast. You can use them for HT as is by just getting used to what setting will hold what tem ( keep a log)....and watching it. For simple steels like 10XX and O-1, I use an identical oven to the one you have. I bring it up to the temp desired,plus about 25 degrees, and get it set to stay there. After it has had about 15 minutes of stable temp, I put in the blades. The temp will fall about 25 degrees while the door is open and due to the steel being cold.I adjust the temp down if needed, but usually it falls to about where I want the HT to run.Soak for 5-10 minutes, open and start quenching. The drop on multiple blades is not enough to be a problem, since the oven holds a lot of heat. Stainless steel packets can be done,too. but it takes a long time to get to 1900-1950F, and that is the top end on these burnout ovens. Not really worth the wear on the coils to do Stainless in them. I do stainless in my Paragon...or send it out.

[/FONT][FONT=&quot] [/FONT]

 

[Stacy E. Apelt - Bladesmith]

Phyl,
The SSR is just an electronic switch. It has a power cord to it from the AC source (wall outlet) a control input from the PID (That is what turns it on and off), and a power output to the load (the oven). The PID can directly control only small current loads ( relays, solenoids, fans, etc.). A burnout oven requires an SSR.
Stacy

 

[SteelSlaver]

Here is a simple diagram for that PID and SSR. The wires from the AC supply to the PID can be light say 20-24 gauge. It can handle 240vac. I don't know if your oven is 220 or 110. Either will work on this diagram. Mine is 220 and I put a heavy duty 220 switch on my oven, I wired the power cord to it and it breaks both sides of the 220. I used its output terminals to connect my wires for the pid power supply and put an inline fuse holder and a 1 amp fuse on one of the wires where I came off the 220 switch to the pid. On the thermocouple if the temp starts going down when it is working reverse the leads from the pid to the thermocouple. If you have or want a door switch put it on the line from the pid to the SSR. It is very low voltage and power. These can also be very light. Like stated the SSR is simply a switch that the PID turns on. The PID comes with a instruction sheet. Use the last example. When you get it hooked up or are ready I can call you and help out. I have toll free long distance. Shot me an email if you want and make a time to call. Jim

 

[SteelSlaver]

whoops

 

[Phil Dwyer]

Thanks guys. Well, I'll look to get the K thermal couple, PID and SSR stuff like Jim links to. Guess I'll check eBay too. Stacy you make it sound pretty easy. Jim your diagram kind of freaks me out. Thanks for your offer to advise me further.

OK guys, I'm wondering, since the little 110 VAC burnout oven has a manual temperature control dial already, would I just turn it up all the way and let the PID controlled SSR supply the power (to it)? Or, if the PID's small enough (which I doubt) would I just swap it out? Maybe Stacy's idea of just using this little oven manually for simple steels is the way to go and to look to make or procur something a bit more robust for heavier duty.

I'm basically working with 1084, 5160, a bit of 1084/15N20 damascus, and eventually some 52100. Not sure if, and when, I'll tackle any stainless steels.

Mahalo, Phil

 

[SteelSlaver]

Here is a better drawing. The PID is quite small. So is the SSR. 110 is the same as this drawing. The wires you run to your element and the one from your switch to your SSR need to be 12 gauge copper. All the ones to and from the PID can be small like 20-24 gauge. It uses very little amperage. I believe in order to do this neatly you will need to open up the ovens case and figure out where the wires go. You could put the PID and SSR in a small box and instead of hooking to the element connect one leg of the 110 to a 110 female plug, then connect the L1 of the SSR to the other leg of the plug. (keep the plugs the same the wide blade on the oven should be common to the wide blade on the power plug to the SSR/PID box. Connect all the grounds together and to the new plugs ground. Then hook it to the top of the oven, run the thermocouple into the oven and crank the controller on the oven wide open and plug the oven into the plug from the SSR/PID box. The PID would sense the temperature and turn on the SSR which would put power to the plug and turn on the oven, when it was up to temp it would shut down the SSR and thus the power to the oven. Basically the whole oven becomes the element in my drawing. It would work.