OBS dual element mod and PID help

Started by stxhunter, July 29, 2011, 03:40:10 PM

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TonyL222

Wow!!!  That's simple and elegant THANKS!!!!  Now I'm off to Home Depot to get some ring connectors (which wasn't in the parts list for either of the onli documents).

GusRobin

Some lessons learned:
1) Home Depot did not have high temp stuff. Although it stated so, their high temp was in the 200 range. So make sure you check.

2) While the switch is unecessary, it came in handy for me. First was when the PID went down. I was able to use the second element to get up to temp, switch it off and use just the original element for cooking.

3) Another time I blew the sensor fuse which prevented the original element and temp slider from working. I was able to use the second element manually.

My experience is that the small cost and time required for the switch, it was worth installing it.
"It ain't worth missing someone from your past- there is a reason they didn't make it to your future."

"Life is tough, it is even tougher when you are stupid"

Don't curse the storm, learn to dance in the rain.

TonyL222

Thanks GR.  I did go the HD and noticed their Ring connectors were not high temp.  Went to the applicance store where I bought the wire and got HT rings.  I'm certain that you are much "handier" than me, so the switch isn't a big deal for you. MAJOR operation for me.  Maybe later (since I have it).

I still need to notch the ceramic plates so the wire wll fit through.  Other than that, this was quite easy.  No need to even remove the back panel.

TonyL222

Quote from: TedEbear on August 09, 2011, 09:54:10 AM
...  Some say that the original slider control might not be able to handle the additional load of 1000W worth of elements. I don't recommend running two elements with the slider temp control.

Oh SNAP!!!  Overlooked this little caution.  I assumed your only mod to the OBS was the additional element in parallel.  I did run a test with the two elements last night.  Ran it up to 260 (took maybe 15 mins with no load), opened the door to let heat out, then closed to see how it recovered.  All this with both elements on the slider.  No apparent issues in that short 20 min span. Was that a long enough or valid test of two elements on the slider?  Has anyone else been running with two elements on the slider?

I do still have the rocker switch (Bradley replacement) which I bought from Yard & Pool. 

muebe

Quote from: TonyL222 on August 10, 2011, 07:26:05 AM
Quote from: TedEbear on August 09, 2011, 09:54:10 AM
...  Some say that the original slider control might not be able to handle the additional load of 1000W worth of elements. I don't recommend running two elements with the slider temp control.

Oh SNAP!!!  Overlooked this little caution.  I assumed your only mod to the OBS was the additional element in parallel.  I did run a test with the two elements last night.  Ran it up to 260 (took maybe 15 mins with no load), opened the door to let heat out, then closed to see how it recovered.  All this with both elements on the slider.  No apparent issues in that short 20 min span. Was that a long enough or valid test of two elements on the slider?  Has anyone else been running with two elements on the slider?

I do still have the rocker switch (Bradley replacement) which I bought from Yard & Pool.

I have the 900w finned element mod and a Auber PID. I was running that element on the slider for a while until I just recently modified my faceplate(I decided to remove the slider). I had over 60 hours of use on the slider with the 900w element and did not experience any problems. But I always kept it all the way up on high(I have a PID) and it is 100w short of what your load will be. I did notice some discoloration from heat on the PCB at the back of where the heatsink is located. I do not know if this is normal or was caused by the higher wattage element. It does not look burned though. You can see it in the second picture below...

Natural Gas 4 burner stainless RED with auto-clean
2 TBEs(1 natural gas & 1 LP gas)
OBS(Auberins dual probe PID, 900w finned element & convection fan mods)
2011 Memphis Select Pellet Smoker
BBQ Grillware vertical smoker(oven thermostat installed & converted to natural gas)

Habanero Smoker

Quote from: TonyL222 on August 09, 2011, 10:24:45 AM
Wow!!!  That's simple and elegant THANKS!!!!  Now I'm off to Home Depot to get some ring connectors (which wasn't in the parts list for either of the onli documents).

If you daisy chain the elements like TeddyBear suggested; it's advisable to disconnect the temperature controller and wire it so it by passes it. It doesn't take much effort to do that.



     I
         don't
                   inhale.
  ::)

TonyL222


TonyL222

As a recap, installed the 2nd element using the TedEBear method.  Took the slider our of the loop per Hab's recommendation (cut and spliced together)..

Instead of autotune on the PID, I just re-programmed the P factor to 140 and left I and D the same per Auber recommendation.

Smoked a 7lbs bone in turkey breast this Saturday for a test.  I didn't write down temps and times.  But to my recollection, the OBS went heated up from mid 80's ambient to 260 in less than 20 minutes - this with the water bowl filled with room temp water.

Cook temp was 220.  I opened the door to turn the breast, empty and refill bowl.  Temp dropped to around 160, and recovered back to 220 in less than 10 mins.

Imma gonna do two butts for a weekend party and I'll be more diligent about recording - but so far I'm VERY please with results.

I should note that I'm using one pre "recall" element and one post (with a third in reserve).  The older element has been through several prolonged smokes, unlike the first two I have which failed quickly.

GusRobin

You will love it with the second element. If you start with hot water in the water bowl the temp will rise even faster in the beginning.
"It ain't worth missing someone from your past- there is a reason they didn't make it to your future."

"Life is tough, it is even tougher when you are stupid"

Don't curse the storm, learn to dance in the rain.