MES Safety Rollout Limit Switch Located Here

[tallbm]

The MES safety rollout limit switch is a common point of failure so I am making this post to have pictures of it that I can easily find instead of digging up new ones everytime we help someone with this issue. Also adding tags so it's easy to search in SMF and hopefully via Google as well.

Safety Rollout Limit Switch Located Inside Here:


You may have to cut a panel in the back or may have one already installed if lucky. The back of the switch area looks like this when you get to the switch:
(image is mirrored so switch panel should be on the right hand side but mid way up)


The switch itself looks like this once you get to it:



Replacement switches are KSD301 150Celcius/302F.
There are 2 styles of switches which can be EASILY confused so look closely when buying and only use the good style of switch!

Good Style has 1 solid metal button face with fastening wings:

X Bad Style has separate button face and separate fastening wings/collar (notice the 2 separate pieces though):

It is best to get a ceramic ones instead of the plastic ones but either will work. The plastic ones will just more easily melt down on you again.
Ceramic version (white ceramic back)

Plastic version (black plastic back)

• If you rewire your MES and use a PID controller you can go up to a safety switch with a limit of 180Celsius/356F (150C/302F is the limit on the stock switch in your MES)
• BUT don't ever smoke above a 325F smoker temperature
• If smoking 276F- 325F smoker temperature don't go over 4 hours. The insulation is not rated to handle the higher temps and times for long.

Often the crappy electrical connectors are failing or corroded and ruin the safety rollout limit switch. In this case you will also need hi temp connectors.

Supco t1111 are 14-16AWG high temp crimp connectors that can be found on Amazon (can be soldered as well):

Supco t1113 are 14-16AWG high temp FLAG SHAPPED connectors that are best for soldering and can be found on Amazon as well:

I hope this info helps and I hope it is easily search able to help others with :)

 

[Coreymacc]

Not to be a mr know it all but if this is electric smoker its a high limit switch, not a roll out switch. Roll outs are for gas appliances and detect flame or "roll out of flame". Limit switches detect a higher than normal temp and trip for saftey. Or am i missing something?

Corey

 

[chopsaw]

High limit is the correct term , but most here know what he's talking about .
Good info either way .

 

[tallbm]

Not to be a mr know it all but if this is electric smoker its a high limit switch, not a roll out switch. Roll outs are for gas appliances and detect flame or "roll out of flame". Limit switches detect a higher than normal temp and trip for saftey. Or am i missing something?

Corey

No problem :D

I am not a switch expert by any means so I won't claim to be an authority on the naming of these switches :)

I can say that when looking at these KSD301 switches they seem to be used in appliances that are gas/flame or electric and they get called all kinds of things when doing the product searches.

So I'm thinking that all the possible terms get easily rolled up together to become something like a safety rollout limit switch lol.

I see it called Thermal Switch, Thermostat, Thermostat Switch, Sensor, High Temperature Limiter, etc.

These switches are Normally Closed and open/trip when their temperature threshold is reached. You aren't missing anything in that regard.

I'm not married to any specific term as long as it can be clearly identified as the safety switch that cuts off power when a certain smoker temp is reached :D
As long as we clearly point to KSD301 switches, that should ensure the correct part is used replace the ones that burn up so often in the MES units :)

Clear as mud aye? :D

 

[cmayna]

Nice write up for those running into these issues in the future.

 

[Fueling Around]

Nice write up.
Great idea to create a new thread.

After all these years of problems with poor connections and an ever-failing limit switch
you'd think they would spend a couple dollars more on the build and save some dollars on the warranty side.

 

[MJB05615]

Great post and great info as always. I soldered my Auber PID wired directly to the heating element more than 2 years ago. Never had a problem as this bypassed the High Limit switch. I know it's a safety feature, but I never smoke above 250'.
And never leave when the smoker is in use.

 

[tallbm]

Nice write up for those running into these issues in the future.

Thanks!

Nice write up.
Great idea to create a new thread.

After all these years of problems with poor connections and an ever-failing limit switch
you'd think they would spend a couple dollars more on the build and save some dollars on the warranty side.

Thanks!
Yeah I agree. Just use a ceramic switch and hi temp connectors! But I guess they cut all costs possible. So we fix what we can :D

Great post and great info as always. I soldered my Auber PID wired directly to the heating element more than 2 years ago. Never had a problem as this bypassed the High Limit switch. I know it's a safety feature, but I never smoke above 250'.
And never leave when the smoker is in use.

Thanks!
Yep your approach gets it done as well!