Avoid Temp Swings in MES (By Bear)

[jp61]

Not sure which sensors you guys are talking about but, if I remember correctly my gen1 40" MES has three temp sensors..... meat, chamber and (safety) high temp cut-off. They all should have at minimum those three sensors.

 

[Bearcarver]

 
Not sure which sensors you guys are talking about but, if I remember correctly my gen1 40" MES has three temp sensors..... meat, chamber and (safety) high temp cut-off. They all should have at minimum those three sensors.

Right---We're talking about the two other than the meat probe.

It seems one of the new MES only has one on the back wall, instead of two, like most of us have.

We're guessing the "Chamber Temp & the Safety cut-off" are rolled into one on that new one, but not on other new ones.

Bear

 

[bigd3077]

The last 2 smokes I did were all over. Due to wind, and my stack mostly. I am going to put sand in my drip tray next time, and follow your advice on pre heating Bear. The sand will never be 0* here in south florida, so if it takes an extra 15 minutes or so to heat, I'll take it.

 

[jp61]

 
Right---We're talking about the two other than the meat probe.

It seems one of the new MES only has one on the back wall, instead of two, like most of us have.

We're guessing the "Chamber Temp & the Safety cut-off" are rolled into one on that new one, but not on other new ones.

Bear

hmmm... OK.

I guess that's a possibility, I don't know..... haven't paid much attention to any MES smoker newer than mine. Probably the easiest way to find out is customer service, maybe wiring diagrams? Is it on the top section?

 

[Bearcarver]

 
The last 2 smokes I did were all over. Due to wind, and my stack mostly. I am going to put sand in my drip tray next time, and follow your advice on pre heating Bear. The sand will never be 0* here in south florida, so if it takes an extra 15 minutes or so to heat, I'll take it.

Yup---That should work a lot better down there.

Also--Note---The only time I have my Top Vent open at only 50% is when it is Windy.  Seems to help keep the heat from getting sucked out.

Bear

 

[Bearcarver]

So. Here are the results of my testing. Of course this could all moot of Bear is right and I'm testing the wrong sensor, but I don't think I am.

If you look closely at this picture...

image.jpg

• floridasteve
• Jun 28, 2015

 

Hey Steve,

Now that I look closer at your picture (above), I believe I see the toggle switch looking sensor at about 11 O'Clock about an inch below the rack above.

That would be the Heat Sensor. The one you have your probe near is the Heat Safety Sensor.

Bear

 

[Bearcarver]

 

[Bearcarver]

 
hmmm... OK.

I guess that's a possibility, I don't know..... haven't paid much attention to any MES smoker newer than mine. Probably the easiest way to find out is customer service, maybe wiring diagrams? Is it on the top section?

False Alarm---See Post #106.

Bear

 

[jp61]

 
Hey Steve,

Now that I look closer at your picture (above), I believe I see the toggle switch looking sensor at about 11 O'Clock about an inch below the rack above.

That would be the Heat Sensor. The one you have your probe near is the Heat Safety Sensor.

Bear

 

[daricksta]

 
Exactly. I thought that was a given, which is why we don't even consider what the meat probe says when it's in its holder, and why we never let any measuring part of a probe lay against any metal in our smokers, and expect any accuracy in measuring the air temp.

Some people support their probes with a potato, some use a block of wood to keep their probes away from metal, and I hang mine through a rack with electrical tape on the top to secure the probes from moving from where I put them.

You can see that in my picture above, where I have a probe on each side to balance out the heat from left to right with the use of my heat deflector below.

Bear

I never knew that the back wall acted as a heat sink. I keep the ET-733 BARBECUE probe near the rear of the rack and either more or less pointing to either the left or right side. I know there are different temps in different areas of my MES 30 Gen 1 but I decided just to keep the probe in the same spot with every smoke just to standardize the interior heat displayed on the ET-733 display screen, which I use to adjust the temp settings on the smoker. Do you suggest pointing the probe towards the left side or to the right?

Lastly, I just re-read a response from Darryl to a PM of mine about temp swings. I forgot that he had stated that during the initial warm up cycle the residual heat in the element will overshoot the target but after several cycles the temp will settle down close to the target, +/- 5-6 degrees during each cycle. This is exactly what I've been seeing and exactly how you, Jted, and I forget who else explained how the MES controller works.  So the guys who state they don't want to wait the 2-3 hours it might take for the temp to stabilize, well, sorry, but that's the design. From what I understand a PID controller fixes that. For me, it's a slight hassle to adjust the temp at different times during the smoke. My concern is that I don't want it too high or low but throughout all that, I'm watching the IT as displayed on the FOOD probe display screen as it rises toward and then reaches my finish IT.

Also, why do you suppose Masterbuilt reversed the placement of the high temp limit switch and the temp sensor in the 2.5 models?

 

[jp61]

Just

..... I'm not positive but I imagine the safety switch (sensor) is an auto-reset (not manual reset) type of device that's in a normally closed position. If someone ever has a big and/or long enough fire in their smoker or the controller does not shut off the heating element for whatever reason, the (safety) high limit switch should open and not allow the heating element to come back on until, (fire goes out) the safety switch cools off, resets and the controller is calling for heat again. If the controller or relay is ever "stuck" in the on position (always calling for heat) the smoker will cycle on/off of the safety switch at whatever temperature (guessing 375-400°F) it is set at from the factory. This switch should always be in a closed position (continuity) under normal operating conditions. Don't ask..... guess I was bored.

 

[Bearcarver]

 
Just

..... I'm not positive but I imagine the safety switch (sensor) is an auto-reset (not manual reset) type of device that's in a normally closed position. If someone ever has a big and/or long enough fire in their smoker or the controller does not shut off the heating element for whatever reason, the (safety) high limit switch should open and not allow the heating element to come back on until, (fire goes out) the safety switch cools off, resets and the controller is calling for heat again. If the controller or relay is ever "stuck" in the on position (always calling for heat) the smoker will cycle on/off of the safety switch at whatever temperature (guessing 375-400°F) it is set at from the factory. This switch should always be in a closed position (continuity) under normal operating conditions. Don't ask..... guess I was bored.

Thanks---Interesting!!!

I remember a couple years ago there were a few guys who had to warm their MES smokers up with hat water or some kind of heat to get it to start in below Zero Winter Days.

If I remember correctly the problem was with that little safety switch.

Bear

 

[mummel]

Are there any mods or upgrades we can do to the MES 40 BT to get stable temps?  I dont mind spending a few extra $$$ to get it sorted out.

 

[Bearcarver]

 
I never knew that the back wall acted as a heat sink. I keep the ET-733 BARBECUE probe near the rear of the rack and either more or less pointing to either the left or right side. I know there are different temps in different areas of my MES 30 Gen 1 but I decided just to keep the probe in the same spot with every smoke just to standardize the interior heat displayed on the ET-733 display screen, which I use to adjust the temp settings on the smoker. Do you suggest pointing the probe towards the left side or to the right?

Lastly, I just re-read a response from Darryl to a PM of mine about temp swings. I forgot that he had stated that during the initial warm up cycle the residual heat in the element will overshoot the target but after several cycles the temp will settle down close to the target, +/- 5-6 degrees during each cycle. This is exactly what I've been seeing and exactly how you, Jted, and I forget who else explained how the MES controller works.  So the guys who state they don't want to wait the 2-3 hours it might take for the temp to stabilize, well, sorry, but that's the design. From what I understand a PID controller fixes that. For me, it's a slight hassle to adjust the temp at different times during the smoke. My concern is that I don't want it too high or low but throughout all that, I'm watching the IT as displayed on the FOOD probe display screen as it rises toward and then reaches my finish IT.

Also, why do you suppose Masterbuilt reversed the placement of the high temp limit switch and the temp sensor in the 2.5 models?

The first one I've seen was Mummels (Yesterday) and it looks to me like it's now Dead Center instead of a few inches to the right. That seems to be a step in the right direction.

Picture in Post # 97 of this Thread.

Bear

 

[daricksta]

 
Not sure which sensors you guys are talking about but, if I remember correctly my gen1 40" MES has three temp sensors..... meat, chamber and (safety) high temp cut-off. They all should have at minimum those three sensors.

Not all the MES smokers have the meat probe. My MES 30 Gen 1 only has two: the chamber and hi temp limit switch. I use my Maverick ET-733 for both the meat and for an accurate chamber temp reading.

 

[Bearcarver]

 
Not all the MES smokers have the meat probe. My MES 30 Gen 1 only has two: the chamber and hi temp limit switch. I use my Maverick ET-733 for both the meat and for an accurate chamber temp reading.

You aren't missing anything. I've said many times I wouldn't trust it anyway, if not for any other reason than I wouldn't know how to boil test it.

Bear

 

[daricksta]

 
Just

..... I'm not positive but I imagine the safety switch (sensor) is an auto-reset (not manual reset) type of device that's in a normally closed position. If someone ever has a big and/or long enough fire in their smoker or the controller does not shut off the heating element for whatever reason, the (safety) high limit switch should open and not allow the heating element to come back on until, (fire goes out) the safety switch cools off, resets and the controller is calling for heat again. If the controller or relay is ever "stuck" in the on position (always calling for heat) the smoker will cycle on/off of the safety switch at whatever temperature (guessing 375-400°F) it is set at from the factory. This switch should always be in a closed position (continuity) under normal operating conditions. Don't ask..... guess I was bored.

The hi limit cutoff switch is designed to shut down the heating element if the smoker gets up to between 325-350°. I've never had it kick in so personally I don't know if it opens up after the temp goes lower than 325° or if you have to manually push the On button again and reset your set point and smoking time. The highest temp my smoker has reached is 302°.

 

[daricksta]

 
You aren't missing anything. I've said many times I wouldn't trust it anyway, if not for any other reason than I wouldn't know how to boil test it.

Bear

Excellent point.

 

[daricksta]

 
The first one I've seen was Mummels (Yesterday) and it looks to me like it's now Dead Center instead of a few inches to the right. That seems to be a step in the right direction.

Picture in Post # 97 of this Thread.

Bear

From your experience, what would be the best spots for placing the temp sensor and the hi temp limit switch?

 

[jp61]

 
Not all the MES smokers have the meat probe. My MES 30 Gen 1 only has two: the chamber and hi temp limit switch. I use my Maverick ET-733 for both the meat and for an accurate chamber temp reading.

OK.... didn't know that, assumed both size smokers had a meat probe. I guess one has to spend the big $$$ to get an extra bell/whistle. You should consider yourself fortunate they gave you a chip-loader with your 30".