Heat Treating Oven issues

C

CalKidd

Joined
Feb 22, 2022
Messages
14
I am not sure where to go; I came here because James Keeton (Red Beard Ops) posted some of his questions here regarding the build of his heat treating oven. I built a heat treating oven basically identical to Red Beard Ops and I have ran into a few issues. I am using a Auber SYL-2352P PID, with two InkBird 40 amp SSR, 16ga Kanthal A1 coil with an overall resistance value of 18.2 omhs using 240 volt power supply. The oven internal dimensions at 6.5" x 5" x 18".

1. I set the Auber to 1500°, it got up to 945° and stalled. After some tinkering and opening up the door I was unable to get it back up in temperature; I got fed up and shut it off. Interesting thing as it cooled down the PID started to read negative degrees, which we all know this was not a true reading, while the temperature inside was hot enough not to get my hands near it. I assume the thermocouple is bad thus not allowing the oven to come up to temperature?

2. During the first cycle of heating the two front bricks cracked. I assume this will not effect the performance of the oven.





 
What type of thermocouple did you use and how did you wire it? They require special wire, each leg is a different type, IIRC.

I can't tell from the picture, do you have heat sinks for the SSRs? They tend to run hot and heat sinks are typically needed.
 
It is a K Type thermocouple and I used 24 awg thermocouple specific wire. I bought the thermocouple from Amazon and it came from China and I am afraid the quality is garbage. I used a heat gun and watched as the temperature dropped thus the wires were backwards. I flipped the wires at the back of the thermocouple. Do I need to also switch the wires at the PID?

Yes, the two SSR have heatsinks installed.
 
Last edited:
CalKidd said:
It is a K Type thermocouple and I used 24 awg thermocouple specific wire. I bought the thermocouple from Amazon and it came from China and I am afraid the quality is garbage. I used a heat gun and watched as the temperature dropped thus the wires were backwards. I flipped the wires at the back of the thermocouple. Do I need to also switch the wires at the PID?

Yes, the two SSR have heatsinks installed.
Click to expand...
I'm not entirely sure about how they need to be connected from your description. You can test by using the heat gun on the connection at the back of the thermocouple. If heating the connection instead of the thermocouple changes the temperature, then you probably have them switched. In that case, you need to switch them back the way you had them and switch them at the PID.
 
Ok. I found an old post from Red Beard. It's looks like the wires are also specific to the positive and negative. By switching one side doesn't not alleviate the issue unless you switch at both ends, that's if i read the post right. So. I'll switch the wires at the PID to see if that works. I am basing this off when I used a heat gun at the back of the TC the temp decreased.

Also this Auber controller is daunting. There are so many parameters.
 
CalKidd said:
Ok. I found an old post from Red Beard. It's looks like the wires are also specific to the positive and negative. By switching one side doesn't not alleviate the issue unless you switch at both ends, that's if i read the post right. So. I'll switch the wires at the PID to see if that works. I am basing this off when I used a heat gun at the back of the TC the temp decreased.

Also this Auber controller is daunting. There are so many parameters.
Click to expand...
The thermocouple is made of two different wires that are connected at the tip of the thermocouple. If you connect the wires incorrectly, you essentially create a new thermocouple at the junction. You have to use the same wire from the tip of the thermocouple all the way to the PID, and connect it to the correct terminal. Luckily, not too many combinations, so you can get it right by trial and error fairly quickly.

I looked at the manual for the ramp and soak version of the Auber controller when I built my oven and opted for the regular one because it seemed too much hassle to program the ramp and soak controller. My regular Auber controller has worked very well, I just used the auto-tune feature and it holds temperatures within a tight margin. I'm sure the one you got will do the same thing, once you got it programmed. I would recommend you try the auto-tune first and only worry about all the parameters if you really need to.
 
It looks like the control wires to the SSRs are wrong. There should be a + and a - wire to one SSR and jumpers to the second one. It looks like there is a red plus lead, but the minus looks like it is missing.
 
Stacy E. Apelt - Bladesmith said:
It looks like the control wires to the SSRs are wrong. There should be a + and a - wire to one SSR and jumpers to the second one. It looks like there is a red plus lead, but the minus looks like it is missing.
Click to expand...
That red wire is the lead that goes to the manual coil wire switch (top switch on the box) and from the switch to the PID. There is another white wire going to the door switch from the negative on the SSR. I used the red 14 ga wire for operations to the PID since the current is so low.

I checked the voltage at the coil output on the SSR during operation. I was getting 120v from each terminal. So I believe the SSR's are working properly.
 
Hubert S. said:
The thermocouple is made of two different wires that are connected at the tip of the thermocouple. If you connect the wires incorrectly, you essentially create a new thermocouple at the junction. You have to use the same wire from the tip of the thermocouple all the way to the PID, and connect it to the correct terminal. Luckily, not too many combinations, so you can get it right by trial and error fairly quickly.

I looked at the manual for the ramp and soak version of the Auber controller when I built my oven and opted for the regular one because it seemed too much hassle to program the ramp and soak controller. My regular Auber controller has worked very well, I just used the auto-tune feature and it holds temperatures within a tight margin. I'm sure the one you got will do the same thing, once you got it programmed. I would recommend you try the auto-tune first and only worry about all the parameters if you really need to.
Click to expand...
Thanks for the replies. I'll probably stick with this PID since it's already installed. I am sure I'll get it figured out. I just need to watch videos and learn the specific settings I'll need for knife making. I watched James bring his oven up to 1500⁰ and then he ran AT. I'll give that a go.
 
I have replaced the TC wire. I used a magnet to find the ferrous wire of the TC and installed back in the TC block with the magnetic wire as the positive. I wired the yellow to positive and the red to the negative. I am waiting on a reply as to why the TC wire burnt before I fire this oven up again.
 
You said you get 120VAC from each of the the SSR outputs, but are you getting 240VAC when you meter across both?

Are you sure your PID is set to F and not C?

You can test your TC with a cup full of ice water. It should read at (or very near) 32F when stirred into a cup of ice water. Is it reading something that approximates your shop's room temperature when the coils haven't been heated yet?

As for why your TC wire burned, could it be from the heat absorbing through your bricks and/or TC? You may want to use some high temp wire for that connection, at least within a few inches of the oven.

BTW, I'll recommend you get a pint of ITC-100 coating for the inside of your bricks. It'll increase the efficiency of your oven and help you hold set point a lot better.
 
I have not tested across the two outputs for 240v.

After replace the wire and finding positive I tested the connection. When I put a heat gun to the back of the TC the temps increased. When I put the heat gun into the oven the temps decreased. Even thought I checked the TC elements with a magnet it appears it is wired backwards even though the magnetic test says otherwise.

I am using TC specific wire that is shielded in woven fiberglass. Maybe I'll run the wire on the outside of the Kaowool away from the bricks.
 
CalKidd said:
I have not tested across the two outputs for 240v.

After replace the wire and finding positive I tested the connection. When I put a heat gun to the back of the TC the temps increased. When I put the heat gun into the oven the temps decreased. Even thought I checked the TC elements with a magnet it appears it is wired backwards even though the magnetic test says otherwise.

I am using TC specific wire that is shielded in woven fiberglass. Maybe I'll run the wire on the outside of the Kaowool away from the bricks.
Click to expand...
I would run all wires outside the kaowool, that's how mine is set up.
 
So, I think the TC is bad. I put the TC in ice water and it first read 41⁰. I switched the wires and it read 86⁰. When I switched the wires back it read 46⁰.
 
CalKidd said:
So, I think the TC is bad. I put the TC in ice water and it first read 41⁰. I switched the wires and it read 86⁰. When I switched the wires back it read 46⁰.
Click to expand...
You should be able to calibrate your PID so that the TC reads 32 when in the ice water. Make sure your connections are clean and tight and that it's a single, continuous wire from TC to your PID terminal.
 
Thanks Drew. I have looked at the manual and online and I cannot find how to calibrate the TC. Do you happen to know?
 
I didn't see where you live. In some places the TC wire color code is the opposite of the SAE code. Also, verify that the + and - of the TC are right. last, , are you sure you have type K TC wire?
 
I am in the US here in Ca. So I assume the yellow is + and the red is -. I ordered it off of Amazon and it was labeled as a K type TC. I ordered another TC, but unlike the no name brand this one is a Skutt brand and will probably work better.
 
You must log in or register to reply here.
Back
Top