HM controlling electric smokers . . . .
- Thread starter MANowell
- Start date
ChristakisS
New member
Yes, it seems so. You will need a Solid State Relay to control the heating element, this replaces the fan. There's some minor tweaks that you need to in the settings to reflect that you have a SSR instead of a fan but I understand it's not too erroneous. I'm currently building a HM to control Bradley smoker, I'll do a quick post with my experience with tips when it's up and running.
MANowell
New member
Outstanding! I'm envisioning a fan-based one on a Big Green Egg, too.
Any links I should be looking at?
MANowell
New member
Love your avatar, Steve, I have a shirt with that logo on it!
I looked for threads on hacking the MES, wiring wise, and haven't found any yet. I'm not opposed to opening it up and cutting out what is not needed, but it'd be nice to have a guide to what I don't need to take apart.
RalphTrimble
TVWBB Diamond Member
I've never done this but I've read a few threads about using the HM to control an electric smoker over the past couple years, search out "SSR" or "Solid State Relay" on the board and you should come up with some threads to read over...
The general concepts are this. The HM has a variable low voltage DC output to control a fan, an electric smoker will have a heater element that is likely running on 110VAC (an assumption on my part, you need to verify what voltage your element is running but my guess is 110VAC). To have your HM control the electric element you need to use a device called an SSR (Solid-State-Relay) which will use the low voltage DC from the HM to switch on/off the higher voltage AC circuit that powers your element. You need to make sure the SSR you choose can handle the output voltage and current that your heater element requires and the control voltage should be 12VDC. (If you look up threads here I am sure some folks have given out part numbers on the SSR's they use) Since the HM fan output is variable (the fan will ramp up in speed rather than pulse on/off at max speed) you need to set the Min/Max both to 100% in the HM config so the HM will just put out pulses of 12VDC rather than ramping up the voltage.
I would think the conversion would be fairly simple, disconnect the heating element from the existing control circuit, connect the heating element to the SSR instead, connect the required source voltage to the SSR, connect the HM fan output to the SSR control voltage terminals. Keep in mind, the HM itself is low voltage DC and pretty much safe to mess with, an electric smoker has AC voltage that is dangerous, so observe caution and never work with it plugged into the wall. Make sure things are mounted right, insulated wires/terminals etc so nothing can short out or be touched!
I'm not sure if you will find a "How to.." thread on your exact smoker here, but perhaps, IDK what these guys are running.... but it seems unlikely the few guys that have posted about this were using the exact same smoker you have. Just follow the general concepts and safety precautions and do a little exploratory surgery and you'll figure it out...
The general concepts are this. The HM has a variable low voltage DC output to control a fan, an electric smoker will have a heater element that is likely running on 110VAC (an assumption on my part, you need to verify what voltage your element is running but my guess is 110VAC). To have your HM control the electric element you need to use a device called an SSR (Solid-State-Relay) which will use the low voltage DC from the HM to switch on/off the higher voltage AC circuit that powers your element. You need to make sure the SSR you choose can handle the output voltage and current that your heater element requires and the control voltage should be 12VDC. (If you look up threads here I am sure some folks have given out part numbers on the SSR's they use) Since the HM fan output is variable (the fan will ramp up in speed rather than pulse on/off at max speed) you need to set the Min/Max both to 100% in the HM config so the HM will just put out pulses of 12VDC rather than ramping up the voltage.
I would think the conversion would be fairly simple, disconnect the heating element from the existing control circuit, connect the heating element to the SSR instead, connect the required source voltage to the SSR, connect the HM fan output to the SSR control voltage terminals. Keep in mind, the HM itself is low voltage DC and pretty much safe to mess with, an electric smoker has AC voltage that is dangerous, so observe caution and never work with it plugged into the wall. Make sure things are mounted right, insulated wires/terminals etc so nothing can short out or be touched!
I'm not sure if you will find a "How to.." thread on your exact smoker here, but perhaps, IDK what these guys are running.... but it seems unlikely the few guys that have posted about this were using the exact same smoker you have. Just follow the general concepts and safety precautions and do a little exploratory surgery and you'll figure it out...
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ChristakisS
New member
Works like a charm, thank you.
@MANowell, wiring is very easy, see image below. Basically for the Bradley smoker you need a spare computer power supply cable which you cut it in half. You then put the SSR between the brown cables (LIVE) on the HV side and then use some connector. Then get an ethernet cable chop one end off, put the blue wire on the (-) of the DC control side of the relay and the blue/white cable on the (+) side. Don't forget to put everything safely in a box to keep you and everyone else safe!
Software setting to use SSR (See Fan Output setting, everything else is irrelevant for this):
I'll run it tomorrow with the smoker to see how it all works out and assuming all goes well, will write a more detailed post with step by step.
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RalphTrimble
TVWBB Diamond Member
Works like a charm, thank you.
@MANowell, wiring is very easy, see image below. Basically for the Bradley smoker you need a spare computer power supply cable which you cut it in half. You then put the SSR between the brown cables (LIVE) on the HV side and then use some connector. Then get an ethernet cable chop one end off, put the blue wire on the (-) of the DC control side of the relay and the blue/white cable on the (+) side. Don't forget to put everything safely in a box to keep you and everyone else safe!
Software setting to use SSR (See Fan Output setting, everything else is irrelevant for this):
I'll run it tomorrow with the smoker to see how it all works out and assuming all goes well, will write a more detailed post with step by step.
Nice job!
You should post the part number and specs on the SSR to make this thread more complete.
Here two good choices for an SSR in this application:
Crydom 50A Zero Cross SSR
Crydom 50A Random Cross SSR
Although the Bradley smokers only draw 5.5A, these SSRs are over-specced for some good reasons:
1. Anything less than 20-25A, and the SSR could not be used without a heat sink, which would add to the cost. Consult the spec sheets for Thermal Derating info if you are unsure. The 10A models are good to 104F, but on a hot day in a small enclosure, this temp could be easily exceeded.
2. Although the Zero-Cross costs ~$4 more, it will have no in-rush current when it cycles the heating element on, which is beneficial for a number of reasons, not the least of which are longevity of both the heating element and the rest of the components on the circuit.
At the time of this reply, I could not find any 20-25A SSRs in stock for less than these 50A models at the usual suppliers such as Digikey or Mouser. I believe Zoro is the low-cost affiliate of Grainger based on part numbers, but I could be wrong. I've purchased other products from Zoro with good results in the past.
Mike
Crydom 50A Zero Cross SSR
Crydom 50A Random Cross SSR
Although the Bradley smokers only draw 5.5A, these SSRs are over-specced for some good reasons:
1. Anything less than 20-25A, and the SSR could not be used without a heat sink, which would add to the cost. Consult the spec sheets for Thermal Derating info if you are unsure. The 10A models are good to 104F, but on a hot day in a small enclosure, this temp could be easily exceeded.
2. Although the Zero-Cross costs ~$4 more, it will have no in-rush current when it cycles the heating element on, which is beneficial for a number of reasons, not the least of which are longevity of both the heating element and the rest of the components on the circuit.
At the time of this reply, I could not find any 20-25A SSRs in stock for less than these 50A models at the usual suppliers such as Digikey or Mouser. I believe Zoro is the low-cost affiliate of Grainger based on part numbers, but I could be wrong. I've purchased other products from Zoro with good results in the past.
Mike
Do you have a link for the SSRs that have been used successfully?
I would probably still go with a 25-50A model with or without a heatsink, based on the temperature derate profiles of the other SSRs I've looked at.
Here is a much better deal: Fotek 25A Zero Cross SSR w/ Heatsink on Amazon
Mike
I would probably still go with a 25-50A model with or without a heatsink, based on the temperature derate profiles of the other SSRs I've looked at.
Here is a much better deal: Fotek 25A Zero Cross SSR w/ Heatsink on Amazon
Mike
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RalphTrimble
TVWBB Diamond Member
https://www.amazon.com/s/ref=as_li_...=88d9eddc243ad0a80f9265307e4e707e?tag=TVWB-20
That link will result in a list of SSR's on amazon. The most common flavor is 40A it seems, which is over 4,000W so that should be plenty of overhead. Most have a very wide control signal range that will cover 12VDC that you need, make sure the output is rated for AC (some are DC-DC). It seems 380 and 480 VAC are the most common, anything above the rated voltage of your heating element is fine so these will work.
The zero cross function seems to be where the price jumps, 10A models are $10 but under rated for what you need. The price escalates from there with the higher amp models... IDK if you need this or not, seems there are opinions on both sides on that issue here....
The zero cross units wait for the sine wave to complete (cross zero) before it will switch on/off the output, while the standard SSR's just cut on/off whenever. The zero cross avoids noise in the output waveform that can result from switching in the middle of a cycle so it it easier on equipment. A heating element is probably the most forgiving type of load you can run so my thought would be the zero cross offers you no benefit, but if someone can confirm it causes premature failure of the heating element or something then I yield to their experience because I have none....
That link will result in a list of SSR's on amazon. The most common flavor is 40A it seems, which is over 4,000W so that should be plenty of overhead. Most have a very wide control signal range that will cover 12VDC that you need, make sure the output is rated for AC (some are DC-DC). It seems 380 and 480 VAC are the most common, anything above the rated voltage of your heating element is fine so these will work.
The zero cross function seems to be where the price jumps, 10A models are $10 but under rated for what you need. The price escalates from there with the higher amp models... IDK if you need this or not, seems there are opinions on both sides on that issue here....
The zero cross units wait for the sine wave to complete (cross zero) before it will switch on/off the output, while the standard SSR's just cut on/off whenever. The zero cross avoids noise in the output waveform that can result from switching in the middle of a cycle so it it easier on equipment. A heating element is probably the most forgiving type of load you can run so my thought would be the zero cross offers you no benefit, but if someone can confirm it causes premature failure of the heating element or something then I yield to their experience because I have none....
MANowell
New member
All great news! My smoke generator is a Bradley, the heater cabinet is a MES 40. It IS 110V, I believe the spec sheet on the MES claimed a 1250 W heating element, so I'll be looking in the 11-12 amp range.
The concept of 100% min/max and pulsed operation makes complete sense. The cable interface look like I would expect it to, also.
The concept of 100% min/max and pulsed operation makes complete sense. The cable interface look like I would expect it to, also.
ChristakisS
New member
The 40A SSR should be more than fine. I decided to go with the 25A SSR version to avoid the heatsink and still be ok with heat (I've put mine in a small weather sealed box). Mind you the Bradley 500W heating element only draws 2.2A in the UK (230V). At 25A it's still grossly overrated but it was cheap enough.