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Bypass Surgery for the MES 30

Discussion in 'Blowing Smoke Around the Smoker.' started by SonnyE, Mar 6, 2018.

  1. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    OK, so today's goal turned to making my MES 30 be optional to be cord controlled, or standard controlled.
    Retired from 42 + years in the Electrical field, I've seen a couple of things, and done a couple of things. And no matter what it is, there is probably a couple of million ways to do it.

    Here's mine....
    1. Step one was to find the controls in the guts, the element, then figure a way around so it can be cord controlled, with an Auber Control, or my simplistic way an Inkbird Itc-308 digital temperature controller.
    And to do so in a manner that would not modify, nor nay-gate the warranty. In plain Engrish, easily removable and restore-able to OEM.
    And to do so maintaining safety features like the over temperature Snap-disc element cut-out switch, which is a vital safety device.

    2. Nice! My MES 30 has Phillips head screws for the element cover on the back, and for a plastic cover on the bottom where the control printed circuit board is housed. My first peek in was the back, found the elements connections. They are pretty tightly wrapped, having heat shrink tubing fully covering the connections.

    (Click on any picture to enlarge it.)

    Box 1 Element Connections

    No reasons to disturb these, I moved on to the Main circuit board/control cover on the bottom of my version. Laying the MES 30 on it's chip feeder side gave me ready access to the bottom.
    Incidentally, the Yellow/green wire is an equipment ground. it is just routed behind the element connections, and terminates on a case anchor point for the element. Do Not Disturb.

    Box 2 The Main Control PC Board (printed circuit board)
    Okey Dokey, now we are getting somewhere. See the little black box to the right? That is a control relay. The Black wire is the hot leg of the cord. It feeds 120 VAC power into the MES. The red lead goes directly to the heating element. When heating is called for, that relay closes and applies power to the element.
    The White wire is the Neutral of the power cord. It connects the neutral side of the control transformer (center), and feeds directly to the Blue wire. The blue wire goes to the Over Temperature Switch (Snap-disc), then to the heating element via the black wire seen in Box 1. Typical in control circuits like this where the safety side is Normally closed, except if needed to shut down a bad situation. Like over temperature.

    Let's take a moment here. Recall the tiny wires that plug connected to the control on top? (MES 30, top rear control) Well those, and the Temperature probe are plug connected on the left side of the PC board.
    Picture 3
    These connectors are also secured with a dab of silicone glue.
    Do Not Disturb. I'm only showing you these for informational purposes.
    If at some time you need to replace the PC board then you would remove these. But only then.

    Proofing the element circuit, I connected my Ohm Meter to the disconnected Red and Blue wires. This reads through the Element, back through the Snap-disc Over temp safety switch, and to the Neutral side of the Elements circuit.
    20180306_115425.jpg 20180306_115418.jpg
    18.6 Ohms, continuity.
    Circuit good, Element good, Snap-disc closed.

    Now for my method of being able to By-Pass the OEM control, and allow my external Temperature Control to function. (Auber, or Inkbird)
    A simple switch, rated for 10 amps is what I have. My MES 30 has an 800 watt element. It needs 6.66 Amps at 120 VAC. So I chose to use a switch rated for more amps than it requires, as well as the nominal voltage of 120 VAC.
    Simply stated, Amps (I) = Watts (800) / Volts (120) 6.66 = 800/120

    20180306_125431.jpg 20180306_125437.jpg

    I merely put my switch in Parallel with the contacts of the OEM control relay. When my switch is in the "ON" position, it bypasses the control relay, and applies power to the element when plugged in. Which is where the external (Auber, or Inkbird) controller comes into play. Put their sensor into the smoker oven, and they control the heater element, by powering the plug and cord on or off.

    Switch the Bypass switch to "OFF" position, and Wa-La, the OEM MES control comes into play, and the Smoker Oven functions with it's normalcy.

    OK, say you have a lapse and plug it in direct, and the bypass switch is closed, what happens?
    Well, this is why there is a safety device called a Snap-disc in the oven. When it gets too hot, the safety switch opens and interrupts the heating element until the Snap-disc cools enough to reset itself.
    So if you were to plug it in, and try to use the OEM control, but the temperature keeps rising, you're in bypass mode. Check the Bypass switch.

    So this is the way I chose to be able to run my smoker oven with either control method.
    Let's call it, The Bypass Method

    My goal was to be able to control the element with an external temperature control, specifically below 100 degrees, for things like Cheese smoking with a small amount (above Ambient, below 100°) of heat.
    My Inkbird has a high range of 210°. But if I want something out of range for the Inkbird, I simply switch to regular MES control mode.
    But within Ambient to 210°, the Inkbird has a 1 degree +/- resolution.
    Close enough for the fish I smoke... ;)
    Last edited: Mar 6, 2018
    BuckeyeSteve, tallbm and jp61 like this.
  2. jp61

    jp61 Master of the Pit ★ Lifetime Premier ★

    Makes sense to me. Nice job!
  3. mosparky

    mosparky Smoking Fanatic OTBS Member

    Excellent Mod. Exactly what I planned to do when the time comes for mine.
  4. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    Thank You JP. It made sense to me, too.

    Thank You Mosparky. I figured you'd get it for sure. ;)
    The guys in Wyoming often called me "Sparky", too. :confused:
  5. BandCollector

    BandCollector Master of the Pit OTBS Member ★ Lifetime Premier ★

    motocrash likes this.
  6. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    LOL! LOL! LOL! :D
    It's S'OK, it works. ;)
  7. mosparky

    mosparky Smoking Fanatic OTBS Member

    SO, how did you tap into the wires ?
  8. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    Simple solder on the crimped point of the connectors, the switch end had the spade connectors already.
    The Inkbird does the on-off.
    Main idea is for sub-100° heat control. (Cheese) And better temperature in the sub 200's, less bounce than the MES controller.
    Spade splitters (Piggyback) would have been nice. But no gots. So simple solder job hooked it up. And is easily reversible should I need to exchange it. The boots will cover the mod. :rolleyes:
    Last edited: Mar 6, 2018
  9. nanuk

    nanuk Smoking Fanatic ★ Lifetime Premier ★


    So if my limited brain power is seeing this correctly, all you are doing with your switch is creating a path OVER or AROUND the relay to keep the element on.

    If your external control malfunctions and remains hot, the "OverTempSnapDisc" will cut power to the element, and will reset itself when cool enough, then if you have not corrected the problem, it will cycle.

    and your external controller has a female receptacle for the MES main power cord to plug into.

    I think I have this correct
    I like this mod.... very simple and effective.

    I'll have to open mine up and see if it is the same.

  10. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    That is EXACTLY correct, Nanook. Very good!
    Limited brain power my eye!

    The large wires in your picture:
    The Black wire is the Hot, the white wire is the Neutral, the Red wire is the switched to the Element, and the Blue wire goes to the Snap disk and on to the other side of the element.
    That "black box" is the control relay that switches the Hot power leg on, or off.
    Putting a switch (I used a 10 amp rated) so it connects across the Black to the Red bypasses the control relay, giving cord control for an external Auber or Inkbird (or other) means of cord connected control.

    And a bonus is that the snap disk is still there for its safety function, and the temperature read out still works up on top.
    The switch bypasses the control relay of the control board (As if the contacts were always closed). The switch in the Open (off) position allows the original control to function normally.

    My control box is on the bottom, under a plastic cover. (I believe it has 4 screws) Yours, too?

    One last note here: If anyone decides to do this "Bypass Mode", remember the wires to the switch are hot at all times.
    And remember the sensor for your external control (Auber, Inkbird, or other) has to be inside your smoker oven so it sees the temperature it is controlling. ;)
  11. nanuk

    nanuk Smoking Fanatic ★ Lifetime Premier ★

    mine was plastic with 6 screws.

    The plate covering the element leads is loctited, or sealed with something redish.... and the element is welded in, so I see no reason to mess with it at all.

    Your mod is PERFECT for what I am interested in.

    As an option, using DaveOmak's idea of a large dimmer style unit... would work with this mod also, so you'd not have to monkey with the temp settings.
  12. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    Mine is probably 6 screws as well. But I'm too lazy to turn it over to look.
    Not sure about my element. But if it fails, and push comes to shove, I'll go back to my old friend the hotplate. Here is a 1 horsepower version.

    I'm not sure about using a dimmer switch. First, the settings would require some knowledge of where to set it to get to the desired temperature. IF one could find a dimmer rated for the 800 watts the element consumes. I see up to 700 watts, in my very quick search.
    Not saying it wouldn't work, because it would. But would it be a viable option?

    I had a need for something: 1. Cheap, 2. That could cover two methods of cooking (Sous Vide, or my MES 30), 3. That was plug connectable.
    So the Inkbird controller fit my immediate needs, and controls a range of temperature that I use the most.
    Then, with my Bypass switch open, the MES works the same as stock. With the control panel on top.
    Minimal change, maximum versatility, least expense.
    The trade-off is I do not have the programmable features an Auber controller offers. So I have to change temperature steps by advancing the temperature setting of the Inkbird device.
    But that holds true with the MES control, too.

    I do use the cooling function of the Inkbird. Since the Inkbird was for Ambient to 100° that the MES control lacks, for cold smoking, I use the cooling plug to control a fan that blows on the 8' Aluminum tubing to further cool the smoke between the Mailbox Mod and the smoker box.
    The heating function is to inject a little tightly controlled element heat for a good draft and temperature through the smoker itself. It allows me a 70-80 degree temperature area for my "cold" smoking.

    So that's why I did, what I dood, dude. :p Another way to skin a cat... :eek:

    Sous Vide, a Po-Man way.
    A better Ambient to 210° temperature control for the sm00ker. (Because that is the high range)
    With the ease of a simple switch, for original function of the Sm00ker.

    Brewmeisters use Inkbirds for brewing. I just adopted it for my needs. :rolleyes:
    Last edited: May 15, 2018
  13. SonnyE this is really a fantastic mod, but can you show your actual switch connections and how you have the switch in its final mounting position? I really like the versatility of the Inkbird controller I think I would go this route. I barely have my brand new MES 30 (20071814) out of the box and I already want to perform this mod. I'd just like to do all of my due diligence ahead of time!! Thanks in advance :)
    SonnyE likes this.
  14. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    I would, but I'm a long way away in a State far, far away.... :D
    Up in Washington State, here for a Grandson's HS Graduation, then fishin and crabbin and clamming.
    I may not be back for a Month.
    Basically, I merely taped the switch until I decide how I want to mount it. (Up top, or low in front.)
    But I'm leaning towards running it up top so it's easy to reach.
  15. nanuk

    nanuk Smoking Fanatic ★ Lifetime Premier ★

    My version of the MES30c jumper....

    once I get my smoker in a place where I can locate the controls, I'll cut in my switch. I bought a 50amp toggle. (same price as a 10 amp)


    I used 12ga wire, but only had 12ga connectors, so I twist soldered the jumper into the mains, and shrinked it.
  16. nanuk

    nanuk Smoking Fanatic ★ Lifetime Premier ★

    and the NEW TOY!

  17. I'm so glad I found this site, and your Bypass Surgery post. I acquired (free!)a used MES30 with a missing chip pan. I opted to get a cold smoker instead of a pan, so I could have extended smoke without reloading so often. Upon testing the MES thermo, I quickly realized it was far from accurate and lacked good control. Enter your Bypass! After reading your Mod, Smoker Box.jpg I did it and it works great. I already had this WillHi control, so just using it for now. In further testing, I've realized the "cold" smoker still heats the main box a bit much, so I'm trying a couple different ideas, with materials I had on hand. One was to put a 24" extension between the smoker and main box. It helped tremendously, but still could use more cooling. I also "gutted" the main box, leaving only the heating element and tray. Before doing that, it seemed the heater, being directly under the chip tube, heated it up and kept the cooler smoke from entering efficiently. Once removed, draft was vastly improved while hot smoking. I also did a couple minor mods on the cold smoker - namely sealing the lid (creating a silicone gasket surface) and installing an adjustable lid latch so it can be cinched tight against the gasket. Now most of the smoke produced goes into the main box, instead of into the air. PS - real PITA loading chips into the small opening! I made a (prototype)funnel yesterday... a Smoker Toggle.jpg Smoker Control.jpg HUGE improvement.
    SonnyE likes this.
  18. nanuk

    nanuk Smoking Fanatic ★ Lifetime Premier ★

    nice job.
    Like the discreet switch!
  19. SonnyE

    SonnyE Master of the Pit OTBS Member SMF Premier Member

    I apologize for having not seen this sooner, Ell Jay.
    Glad you found my version/method acceptable.
    I use an Inkbird controller for mine, but your WillHi is pretty much the exact same thing.
    It is to hold the IT of the smoker in the low, cold smoking range. Generally meaning less than 100°. Something the MES controller is not meant for.
    I run mine in the 65° - 75° for most of my "cold" smoking needs. And at night when the air here is cool enough to effectively cold smoke (Much of the year).

    If you think you'd like to further control your smoke temperature, you might be interested in what I did with a heavier version of dryer vent tubing. I got a version that is extendable to 96" long. It runs from my "mailbox" around, up, down, and in through a 3" adjustable elbow into the hole where the OEM chip feeder use to be.
    In my experience, the smoke from my AMNPS is only 2° hotter than the ambient temperature by the time it gets to the MES. I can also add a window fan to blow a breese over the tube that the Inkbird controls when it switches off the heating mode and turns on the cooling mode.
    I simply plug in a fan and set it at it's lowest speed behind my smoker equipment.

    I know I go to extremes many may not feel a need for. But the swing in my MES 30 is a mere 6° when cold smoking.
    Of how much value that is worth, I don't know. But my cheese doesn't melt, and my nuts don't roast. :confused:o_O
    I can set it, and forget it, and wake the next day to a finished batch all cooled and smoked ready to bag and tag.

    Nirvana! LOL!:)
  20. SonnyE - I've since taken a few more steps in building my Frankenstein smoker. Haha
    I bought a controller that's capable of up to 572deg (a tad more than necessary) with a 30 amp built-in relay.
    I don't use the main panel controls at all anymore.
    Put a rheostat on the cold smoker - start chips or pellets on full pwr, then reduce to about 40%.
    Pic is the temp box to test the controller. I also pretty much gutted it, removing the chip tray/element hood. The heat trapped there, when using the heating element for normal smoking, seemed to prevent the cooler smoke from entering the main box efficiently MB controller_proto.jpg MB Cold smoke.jpg . (maybe just my imagination)