MES 40 Help

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mneder

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Original poster
Apr 16, 2015
21
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I started a thread a few months ago titled "MES 30 Help" and as a result of all the great inputs I received I purchased an Auber PID for the MES 30 and everything works great.

Recently I was given a MES 40 because the original owner didn't like it because it wouldn't maintain a set temperature. I told him about the Auber PID but he wasn't interested. So I modified the MES 40 to make it compatible with my PID. I disconnected and stowed the existing connections at the two heating element terminals and connected a new power cord directly to the heating element terminals plus a chassis ground. I created the new power cord by cutting one end of of a 10" outdoor extension cord. (NOTE- In doing so I disconnected the MES 40 high temp limit switch which I'm OK with. Basically the Auber is a very expensive high temp limit switch that custs power when the desired temp is reached as opposed to an high temp threshold like the310 degree MES limit switch). The Auber also has an alarm function should some high threshold temp be exceeded (e.g.- grease fire). When I( finished the wiring mod I replaced the small insulated panel cover that covers the wiring for the heater element terminals.

Yesterday I turned on the MES 40 for the first time using the Auber PID. It worked perfectly and maintained the internal temp of 275 degree (+/- 3 degree) for about 3 hours. However, I noticed that the small insulated panel cover was "extremely" hot to the touch. I turned off the PID and allowed to MES 40 to cool down. Then I removed the small panel cover to inspect the wiring. Everything appeared to be normal. No melting, discoloration or brittleness in any of the new connectors or wiring.

Questions-

1. Is it normal for the panel that covers the heating element terminals to become too hot to touch?

2. If it's not normal- what is causing the temp to get so high? Faulty heating element? Wiring mod? Something else?

3. If it is normal- Are there any special precautions I need to take with the modified wiring? Small thermal blanket between the back wall of the MES and the heating element terminals? High temp tape wrap around the power cord wires that are inside the panel area? Remove the insulated panel cover and leave the heating element terminals open? Other?

All thoughts appreciated. I'm getting ready to do another MES 40 test with the PID and I plan to leave a temp probe inside the terminal wiring area with the cover on to see how hot it gets in there and I'll post an update here when available.

UPDATE-
Modification-
a. All connections look tight to me.
b. I used an outdoor extension cord for the new power cord. It is 10 foot, 3-wire, stranded-copper, 16 gauge wire rated for 13 amps and 1825 watts.
c. I used foil tape to secure the cord to the back of the smoker as a strain relief.

Performance-
a. The initial test was at 280 degrees for 3 hours. ( I know- 275 is the maxed rated temp).
b. the second test was 250 degrees for 3 hours. The wiring panel temp stabilized at 200 degrees (see screenshot below).
 

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tallbm

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I started a thread a few months ago titled "MES 30 Help" and as a result of all the great inputs I received I purchased an Auber PID for the MES 30 and everything works great.

Recently I was given a MES 40 because the original owner didn't like it because it wouldn't maintain a set temperature. I told him about the Auber PID but he wasn't interested. So I modified the MES 40 to make it compatible with my PID. I disconnected and stowed the existing connections at the two heating element terminals and connected a new power cord directly to the heating element terminals plus a chassis ground. I created the new power cord by cutting one end of of a 10" outdoor extension cord. (NOTE- In doing so I disconnected the MES 40 high temp limit switch which I'm OK with. Basically the Auber is a very expensive high temp limit switch that custs power when the desired temp is reached as opposed to an high temp threshold like the310 degree MES limit switch). The Auber also has an alarm function should some high threshold temp be exceeded (e.g.- grease fire). When I( finished the wiring mod I replaced the small insulated panel cover that covers the wiring for the heater element terminals.

Yesterday I turned on the MES 40 for the first time using the Auber PID. It worked perfectly and maintained the internal temp of 275 degree (+/- 3 degree) for about 3 hours. However, I noticed that the small insulated panel cover was "extremely" hot to the touch. I turned off the PID and allowed to MES 40 to cool down. Then I removed the small panel cover to inspect the wiring. Everything appeared to be normal. No melting, discoloration or brittleness in any of the new connectors or wiring.

Questions-

1. Is it normal for the panel that covers the heating element terminals to become too hot to touch?

2. If it's not normal- what is causing the temp to get so high? Faulty heating element? Wiring mod? Something else?

3. If it is normal- Are there any special precautions I need to take with the modified wiring? Small thermal blanket between the back wall of the MES and the heating element terminals? High temp tape wrap around the power cord wires that are inside the panel area? Remove the insulated panel cover and leave the heating element terminals open? Other?

All thoughts appreciated. I'm getting ready to do another MES 40 test with the PID and I plan to leave a temp probe inside the terminal wiring area with the cover on to see how hot it gets in there and I'll post an update here when available.

Welcome to the PID club!!! So a few things come to mind.
  1. This extension cord you used, was it at least 16AWG wiring or a lower number? (14AWG, 12AWG, 10AWG, the lower the stronger it is)
    If your wiring is not a strong enough gauge it can overheat on you and cause problems. Many average extension chords are not 16AWG and lower so that could be an issue and definitely an area to simply improve safety even if it isn't the issue.

  2. How secure and tight fitting on the Connectors to the heating element tabs and the wires to the connectors?
    As Winterrider Winterrider mentions, loose fitting connections lead to resistance which leads to overheating.
    As metal heats up it expands which leads to even looser connections and even more heating, and a bad cycle.

    If you can get tight crimps AND solder maybe the double whammy would do the trick for you but if not soldering than just ensuring you have good secure fits and crimps will help.

  3. Have any insulation on the connections?
    Using some heat shrink insulation wrap, some crimp insulators (which I've never looked for) or even so good electrical tape could help insulate and secure things together. Not an end all solution but another thing that could help with securing and keeping things from getting as hot maybe.

Finally, it just gets hotter the closer you get to the heating element so that will simply happen. If you see burning or melting signs on the rubber gasket or any of the wiring or metal then revisit any of the items mentioned above.

I'm hopeful that any/all tweaks above will fix the problem if it truly is a problem.


Get those answers back to us and let us know your thoughts on it all :)
 
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Lonzinomaker

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Were you powering up directly from a wall outlet?
If using an extension cord, it should be a 14 ga (I prefer a 12ga).
I changed my cords out for 12 ga because of voltage drop over distances and they don't get as hot.
 

mneder

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Apr 16, 2015
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Were you powering up directly from a wall outlet?
If using an extension cord, it should be a 14 ga (I prefer a 12ga).
I changed my cords out for 12 ga because of voltage drop over distances and they don't get as hot.
With the PID, the smoker is plugged into the PID and the PID is plugged into the wall outlet. The cable length between the PID and the smoker is approx 9 feet of outdoor extension cord (16 ga, 3-wire, stranded copper). I soldered the stranded wire prior to crimping the quick disconnect to make the wire more like a solid wire.
 

cmayna

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Why is the smoker's new power cord (red cord per above photo) 9 feet long? Isn't the PID sitting on top of the smoker? To me, that length, using 16ga might be a major contributor to the problem.

I just checked my setup and am using 14 ga power cord, about 5 feet long, which is connected directly to the element using high temp wire connectors covered with heatshrink and the other end plugged into Mr. PID.
 
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mneder

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Apr 16, 2015
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I'll look for a 14 ga power cord to replace the 16 ga now installed.

In addition, the cavity where the heating element terminals are located has sufficient room insert a 1 inch thick (maybe a little less) insulation pad that just leaves the heating element terminals exposed. Does anyone have a suggestion regarding the type of insulation to use (or not use)?
 

Lonzinomaker

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If there was insulation there when you opened it I would use a ceramic bat insulation made for kilns and such or fireplace fiberglass insulation.
There may be some air cooling required if there wasn't any insulation previously in place.
 
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mneder

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Original poster
Thread starter
Apr 16, 2015
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That's a thought. Whatever I do I'll repeat the 3 hour operational test with a temp sensor down in the wiring cavity.
 

mneder

Newbie
Original poster
Thread starter
Apr 16, 2015
21
20
That's a thought. Whatever I do I'll repeat the 3 hour operational test with a temp sensor down in the wiring cavity.
Update-

I modified both the MES 30 and MES 40 by inserting a cut-to-size piece of a ceramic fiber thermal insulation blanket (certified to 2300 deg F) in the wiring compartments of both smokers. I bought the insulation on Amazon and it was cheap (approx $12.) I then ran a two hour test at 275 deg. The MES 30 wiring compartment stabilized at 165 deg (110 deg lower than the set temperature), and the MES 40 (having a larger more powerful heating element) stabilized at 185 deg (90 deg lower than the set temperature).

I'm satisfied with the temperature reduction but I'm not entirely happy about using a ceramic fiber insulation because it is not food safe, but it is often used in a insulation in pizza ovens , where the insulation is not directly exposed to the food (e.g.- behind a layer of fire bricks, etc). I think the location of the insulation in the MES wiring compartment is similar to the pizza oven example, where the insulation is not directly exposed to the food.

If someone has a suggestion for a better insulation material please share you thoughts.
 

Lonzinomaker

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I don't think you will get any infiltration of insulation fibers into the inside of the smoker as long as you didn't drill any holes in the inside metal.
 
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tallbm

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Update-

I modified both the MES 30 and MES 40 by inserting a cut-to-size piece of a ceramic fiber thermal insulation blanket (certified to 2300 deg F) in the wiring compartments of both smokers. I bought the insulation on Amazon and it was cheap (approx $12.) I then ran a two hour test at 275 deg. The MES 30 wiring compartment stabilized at 165 deg (110 deg lower than the set temperature), and the MES 40 (having a larger more powerful heating element) stabilized at 185 deg (90 deg lower than the set temperature).

I'm satisfied with the temperature reduction but I'm not entirely happy about using a ceramic fiber insulation because it is not food safe, but it is often used in a insulation in pizza ovens , where the insulation is not directly exposed to the food (e.g.- behind a layer of fire bricks, etc). I think the location of the insulation in the MES wiring compartment is similar to the pizza oven example, where the insulation is not directly exposed to the food.

If someone has a suggestion for a better insulation material please share you thoughts.
I think you are fine. I'm pretty sure the spray in foam insulation used as the MES insulation in the walls (yep foam spray in) is not food safe either.

You can use food safe hi-temp RTV silicon to "caulk" anything around the heating element plate as it is fastened to the interior wall of the MES.
After some smokes all the creosote will seal any edges up. Only holes or gaps would need the RTV.

I know this works because I flipped my element and had to drill new holes and seal old gaps and holes. No issues on my end :)

I think you are ready to smoke some food. Looking forward to see what you make :)
 

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