Heat Treat Oven Issue - Low Max Temp - Auber 2352P

[J. Keeton]

We hit 2000° in 45min

10-4, thanks man. The battle continues. I'll have to dig into the PID manual and try and figure out how to max output this thing on the ramp. I feel like with chamber size, wattage, 240v and my insulation method it should be faster.

 

[timgunn1962]

When it is heating, is the output light constant?

If it is, the controller is doing all it can and the heating rate is being limited by the power available from the elements. The place to look for problems in this case is the elements (Volts, Amps, series or parallel connections, etc), or the structure of the oven: is there an enormous thermal mass, for example?

If the output is cycling, it is the controller that is limiting the heating rate, so that is where you need to concentrate your efforts.

 

[J. Keeton]

T timgunn1962 It doesn't seem to be turning off. I'm going to try and run a cycle with AT=0 tomorrow (on/off) control to see what happens.

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I verified my voltage and ohms. I'm getting 245V to the control box and my elements are giving 17.7 ohms of resistance. That works out to 13.84 amps and 3391 watts. That's 10,017 watts / cubic foot which is superior to the 18'' even heats and paragons (entry models).

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I'm not sure what's going on and looked over the whole oven today to see if there were any obvious issues. The only insulation related thing I can think of is the door seal. It's not perfect and changes some as the oven heats. While I don't really think this is the issue (via a bare hand around the door while operating test....), it could be better.

Have yall used kao-wool as a gasket on the door? I was thinking of trying that since I have some on hand. I also was considering ordering the fiberglass rope gaskets they use for stove doors. What do yall think?

 

[LCoop]

I'm betting it's not a door tightness issue unless it's just blatant. My home built oven gets to 1975 without a gasket but the door is insulated within 30 minutes. But it's double insulated on all 6 sides but door doesn't fit especially tight.

 

[Natlek]

I feel like with chamber size, wattage, 240v and my insulation method it should be faster.

Which bricks you use, different manufacturers, different characteristics . . . . not all are equal in thermal characteristics ?

 

[J. Keeton]

Which bricks you use, different manufacturers, different characteristics . . . . not all are equal in thermal characteristics ?

2500F bricks from Simond Store and 1'' 8# density ceramic fiber.

 

[J. Keeton]

Alight after doing some research on the search it seems my results aren't abnormal:

2018 Thread on Warming Times - https://www.bladeforums.com/threads/heat-treat-oven-warm-up-time.1620302/

2nd 2018 Thread on Warming Times - https://www.bladeforums.com/threads/length-of-time-to-reach-kiln-temp.1576658/


This is a ramp with AT set to 0 (aka "on/off" control), once it got to 1500 I ran the auto tune, and once it leveled off holding +/- 1F; I opened the door for 10 seconds, added a knife, closed the door and timed the recovery. It took about 39 min to get to 1500 and 75 seconds to recover from a 10 second door open.




I think I'm in decent shape here. Thanks guys!

 

[JTknives]

You will want to let the oven soak for at least 1/2hr after it reaches temp before you put a knife in. Just because it says x temp does not mean the chamber has fully equalized.

 

[John Bradshaw Layfield]

I suspect it is the thermocouple. Did you weld the junction after trimming it? If I remember right, the thermocouple wires are two different alloys. Can't hurt to double-check that it is hooked up correctly. You could test in ice water and boiling water, or use a lighter to see if you can max it out. Also, if you open the door and take a look inside, you can probably tell from the color of the oven walls if the thermocouple is reading low.

I'm sure it won't be a door stop for long. Looking forward to the build video.

Which type of thermocouple use for it?

 

[John Bradshaw Layfield]

BTW, a quick test to make sure that the TC leads are right is done with a magnet. The negative side on a type K thermocouple (or wire) is magnetic.

Here is an older post I made on the color codes for TC wires ( red is opposite in different parts of the world):

In type K TC wires the cover is yellow. Inside are two leads - Red is negative and yellow is positive

Thermocouples are polarized. One lead is made from alumel. It is magnetic and is the negative lead ... which connects to the red wire in type K TCs . The chromel lead is not magnetic and is positive .. thus connecting to the yellow lead.

All other plugs, sockets, and TC blocks are polarized, too. Look for the + and - marks.

This is the color code chart for TC wires:
https://www.thermocoupleinfo.com/thermocouple-color-codes.htm

I think below image is complete.

https://maniadsanat.com/articles/استانداردهای-جهانی-رنگ-کابل-ترموکوپل/

 

[Hubert S.]

Which type of thermocouple use for it?

Most people use type K.