Controller build layout questions...

Phil Dwyer

Phil Dwyer

Joined
Feb 28, 2006
Messages
3,494
Hi Folks,

I'm finally getting around to building a temperature controller. Would you look at my layout plans and give me feedback before I start drilling and cutting the case to mount all the components in?

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The fan is at the bottom with the SSR and heat sink mounted above it. I couldn't get the SSR as low as I had planned due to the mounting screws for the composite board the heat sink is mounted to (rather than directly to the back of the metal case). Thus, the fuse and switch are at the bottom of the door to fit in under the SSR as there wasn't enough remaining room to put everything towards the top. I still think the fan should cool the SSR ok though. I'm mounting the fan at the bottom rather than the top as it seems there would be less particulate matter dropping into the case. The PID and bus are at the top mounted to the door.

What say you?

Thanks so much, Phil
 
I say its great. I would use stranded wire on the stuff that flexes when you open the door. I know you won't open it much ,but, a broken wire can be hard to find and cause intermittent problems, which would suck with an oven
 
Looks a lot like mine except I cut a hole in the back of the box and mounted the heat sink on the outside with a fan for maximum cooling. Be sure and use some heat transfer paste (Radio Shack has it) between the SSR & heat sink. I had a SSR burn out which caused burnout of the elements. :grumpy:
 
I mounted the ssr and the heat sink to the back of the kiln, this makes the high voltage and high amperage wiring minimal and the heat is dissapated into the room.
 
Thanks guys! :)

Who would have guessed my next hurtle would be the bloody fuse? I think I bought everyone of these components off of eBay. The ten fuse holders came with ten fuses of your choice. Well, come to find out I didn't get my choice. For some reason the Radio Shack I went to only carried 250V and 32V fuses?! Now I have to track down 110V 15A fuses to get this show on the road. Hmmmmm...... :grumpy:

Not that I've done any of the drilling, cutting and fitting yet, but I did get the thermal compound. At $8 for a couple of grams, I hope I don't loose it like I did my last little package. :o

May you always be giving thanks, Phil :p
 
Okay guys, here are a couple more questions.

I'd like to be able to use the same controller for both the HT oven and the tempering oven. Is it practical? As I see it, here are the challenges....

  • Both ovens need to be brought up to temp and maintained at the same time (a lot of the time.)
  • Moving the TC from oven to oven isn't that effective as it takes a fair amount of time for it to adjust to the temperature differences.
  • Can each oven have it's own TC? If so, what kind of quick disconnect/reconnect should be used and how should it be mounted or interface with the controller box?
  • Each oven has different temperature thresholds. Can the PID be switched between programs as the controller is moved back and forth between ovens?
Here are the TCs and connectors I have on hand...
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Here's the controller so far. The wiring's a mess. I think I got too small of a box (4"x4"x6") and am having a tough time fitting everything and the wiring all in there. I just fabricated a screened air outlet vent that needs to be installed. Yet another hole needs to be made for either a small cable grommet or connector for the TC.
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So, what do you say? Do I need two controllers...or what?

Thanks, Phil
 
Hello Phil,

Your hardware with your quick disconnects for the TC's will work great. I do the same thing with my controller. As long as you are using the same type of TC (e.g. both K type) then plugging from on TC to the other will be no problem. I assume you will not need to use two devices (HT oven and Temper oven at the same time).

Four questions for you:

1) where is the fuse for the PID. You want it to have its own 1 amp fuse to prevent it from being accidentally fried.

2) Are you running your HT oven under 115V 15A?

3) What are the max amps of your HT oven? Mine is 240V, 16A. Just wondering about yours.

4) What AWG wire are you using from your SSR to HT oven?

Eric
 
Hey Eric,

It's good to hear from you. I especially appreciate your not pointing out the dubious quality of my work. Hopefully it will get the job done. I will always admire the superb design and workmanship on all the equipment you have put together. Most excellent. Thanks for helping out here.

efleming said:

Your hardware with your quick disconnects for the TC's will work great. I do the same thing with my controller. As long as you are using the same type of TC (e.g. both K type) then plugging from on TC to the other will be no problem. I assume you will not need to use two devices (HT oven and Temper oven at the same time).
Actually I do need to run them both at the same time. The tempering oven needs to level out at ± 400°F by the time I quench the blade at ± 1500°F from the HT oven.That's why I asked if the PID can be switched between alternate programs when the controller is moved between ovens.

 Four questions for you:

 1) where is the fuse for the PID. You want it to have its own 1 amp fuse to prevent it from being accidentally fried.
 Whoops, not sure I knew about that one. Which line needs to be fused? And the fuse needs to be only 1A, what voltage?

 2) Are you running your HT oven under 115V 15A?
3) What are the max amps of your HT oven? Mine is 240V, 16A. Just wondering about yours.
 It's a small jeweler's burnout oven I got from Stacy Apelt. It's spec'd at 115V 12.7A.

 4) What AWG wire are you using from your SSR to HT oven?
 I'm planning to wire a female 115V receptacle, probably with 12 gauge, maybe 14ga, wire. The oven(s) would just plug into that.
Click to expand...
I've been working from Stacy's tutorial, [/COLOR]http://www.bladeforums.com/forums/showthread.php?t=599423 and Jim Viall's schematic, http://www.bladeforums.com/forums/showpost.php?p=5982545&postcount=7

All the best, Phil
 
Hello Phil,

Thanks for the nice comments regarding workmanship. You are doing a fine job.

Not sure how you could use one controller to handle two ovens at once with two different programming cycles. Seems you would need two controlling devices to do this.

I would just pre heat the Temper oven then switch the controller from your HT oven over to the Temper oven, set the new temp parameters and let it stabilize from there. Shoud be pretty quick.

Here is a schematic showing the two fuses. --> http://www.bladeforums.com/forums/showpost.php?p=5008952&postcount=24 My fuse for the controller is 1A at 240v as that is what I am running in my setup. The fuse labled 40A is actually a 20A. Don't know how that got mis labled. :rolleyes: In your case a 1A 115V fuse would work well to protect the PID.

Here is a good reference for wire gage as it relates to amperage usage --> http://www.powerstream.com/Wire_Size.htm Sounds like your wire choice is well within the prescribed limits for your amperage.

It's looking good Phil. Keep us posted on how it's coming.

Eric




Farmer Phil said:
Hey Eric,

It's good to hear from you. I especially appreciate your not pointing out the dubious quality of my work. Hopefully it will get the job done. I will always admire the superb design and workmanship on all the equipment you have put together. Most excellent. Thanks for helping out here.

I've been working from Stacy's tutorial, [/color]http://www.bladeforums.com/forums/showthread.php?t=599423 and Jim Viall's schematic, http://www.bladeforums.com/forums/showpost.php?p=5982545&postcount=7

All the best, Phil
Click to expand...
 
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