Need help designing custom pellet stove controller?

[hyfire]

I would know if its possible to design, your own pellet stove controller, with software and a PC attached to the stove, can this be done? I don;t have any experience in making this on my own. I want to turn on and off extra fans and devices when needed at certain temps, for example.

 

[MCPO]

I modified (isolated) the ability to manually control the distribution fan on my P-38 so it would come on even at the lowest burn settings . It was necessary for me to do during the shoulder seasons. I can either work it manually or back to auto mode at the flick of a switch and it works flawlessly.

Of course I bought my P-38 used so no worries about the warranty. Then again , If the stove burns the house down and the insurance proves my mod was the cause and therefore refuses to pay , that could be an issue and something for you to think about. We do our thing and take our chances. Such is life.

 

[hyfire]

Thanks for the heads up, I guess I' just build some external fan controller, that varies an external fan speed based on air temperature from the stove vents,

 

[tjnamtiw]

http://www.comfiletech.com/cubloc-youcannowprogramusingladderorbasic.aspx

I have toyed with using the inexpensive Cubloc technology to control my stoves and have gone as far as write a program in ladder logic. It's quite easy to do if you have some experience with ladder logic otherwise it also works with Basic language. Very flexible. You can add lights to indicate that various switches and fans are working if you like.

 

[hyfire]

http://www.comfiletech.com/cubloc-youcannowprogramusingladderorbasic.aspx

I have toyed with using the inexpensive Cubloc technology to control my stoves and have gone as far as write a program in ladder logic. It's quite easy to do if you have some experience with ladder logic otherwise it also works with Basic language. Very flexible. You can add lights to indicate that various switches and fans are working if you like.

How much does that cost?

 

[tjnamtiw]

Go to the website http://cubloc.com/product/01_01.php, decide how many IO's you need, then go to http://cubloc.com/product/01_03.php to find the matching board. Then decide if or not you need output relays. An 8 relay board is only $29. You should end up around $200 to $250. The software is free! Unlike a lot of other controllers where they screw you a bunch for the software.

 

[hyfire]

That is not bad, what can you do within the ladder logic, can you do pwm and interval timing?How can i get temperature sensors int the system.

 

[tjnamtiw]

At this point, I encourage you to download their free software and manuals. Also, read up on ladder logic. You can also use basic subroutines within the ladder logic and vice versa. Look at the controller specs for pwm availability. There are as many timers as you want. For me, using snap discs would be the simplest way to address temps.
Spend some time looking at the literature and play with some programs.

 

[76brian]

I've been tossing around the idea of replacing the controller in my P43 with an Arduino (programmable micro controller). I'd also add on an LCD panel to display temperatures, voltages, status, etc. Electrically speaking it should be pretty simple to do, the code on the other hand would take a while for me to work out. If you can't write C code, it's probably not the best idea to try this.

I'll probably see if I can find a used stove with a bad controller to convert first, instead of butchering my stove.

 

[Harvey Schneider]

You have to really understand the pellet stove and all of the things that can go wrong before you can write software that will safely control a stove. I am sure there were plenty of horror show failures in the early days of pellet stove design, where the controls did not provide safe shutdown when things went wrong.
If you have such a mishap with your custom control system, your homeowner's insurance may not cover you. At the very least I doubt that any fire inspector would sign off on a fuel storage permit for such an installation.

 

[hyfire]

It just an interesting concept, like I said it could be used to control other devices to work in harmony with the stove... A windows tablet showing everything would be sweet!

 

[SwineFlue]

It just an interesting concept, like I said it could be used to control other devices to work in harmony with the stove... A windows tablet showing everything would be sweet!

I know what you mean (but personally I wouldn't trust Windows to control a birthday candle). I love the simplicity of the Quadrafire (controlled by a vacuum switch, 3 snap disks, and 1950s technology circuits in the control box), but I have often thought about stuff like using the thermostat to control the heat output instead of on/off.
It's just that we could never make it as reliable as the manufacturers. Would you trust your house/family with your own controller?

 

[Harvey Schneider]

It just an interesting concept, like I said it could be used to control other devices to work in harmony with the stove... A windows tablet showing everything would be sweet!

You don't need a control system in order to monitor the stove. You can instrument the stove so that all parameters can be monitored and displayed. Just be careful that your wiring doesn't compromise the controls.
Windows is an extremely unstable system and should never be allowed to control anything important.

 

[76brian]

Windows is an extremely unstable system and should never be allowed to control anything important.

lol, if you say so

 

[moey]

You could buy a LUX100 its a programmable outlet thermostat. It works very well Ive used them for oil filled radiator heaters in bedrooms.

http://www.amazon.com/Lux-Heating-Cooling-Programmable-Thermostat/dp/B000E7NYY8

 

[tjnamtiw]

I've been tossing around the idea of replacing the controller in my P43 with an Arduino (programmable micro controller). I'd also add on an LCD panel to display temperatures, voltages, status, etc. Electrically speaking it should be pretty simple to do, the code on the other hand would take a while for me to work out. If you can't write C code, it's probably not the best idea to try this.

I'll probably see if I can find a used stove with a bad controller to convert first, instead of butchering my stove.

I used to write C language even before C++ but that's why I like the CUBLOC system over the Arduino. I used ladder logic on all of my control systems for automation at work and it makes it so much simpler. It's pretty easy to understand and master. And who hasn't used good ole Basic at one time or another if you want to write in that? AND the prices are really reasonable. Of course, if you want displays, then it's cost goes up, as expected.
Another more industrial version comes from Automation Direct, which we used at work sometimes. Of course, the price is higher and you have to buy their software but it is good equipment and pretty easy on the budget.

 

[tjnamtiw]

You have to really understand the pellet stove and all of the things that can go wrong before you can write software that will safely control a stove. I am sure there were plenty of horror show failures in the early days of pellet stove design, where the controls did not provide safe shutdown when things went wrong.
If you have such a mishap with your custom control system, your homeowner's insurance may not cover you. At the very least I doubt that any fire inspector would sign off on a fuel storage permit for such an installation.

That's why I would never make such a controller for someone else or give them code. Too much liability. As for functions of a Quad, they are pretty dirt simple and if you can't copy the logic for running and safety checks, then you have no business even THINKING about doing it!
Fuel storage permit????? Oh, you live in New England!

 

[tjnamtiw]

I know what you mean (but personally I wouldn't trust Windows to control a birthday candle). I love the simplicity of the Quadrafire (controlled by a vacuum switch, 3 snap disks, and 1950s technology circuits in the control box), but I have often thought about stuff like using the thermostat to control the heat output instead of on/off.
It's just that we could never make it as reliable as the manufacturers. Would you trust your house/family with your own controller?

Actually, I WOULD trust it, because I would have it provide me MORE info on running conditions as well as trouble shooting indications and possibly additional safety checks such as CO and smoke monitoring as well as stack temps integrated into its controls. Maybe even a smoke detection in the hopper. Endless possibilities. And since I worked with the controllers for over 20 years, I could probably come up with a decent system. (Actually, I already have!)......

 

[SwineFlue]

Actually, I WOULD trust it, because I would have it provide me MORE info on running conditions as well as trouble shooting indications and possibly additional safety checks such as CO and smoke monitoring as well as stack temps integrated into its controls. Maybe even a smoke detection in the hopper. Endless possibilities. And since I worked with the controllers for over 20 years, I could probably come up with a decent system. (Actually, I already have!)......

I don't doubt that at all. I might do something also, but I'd likely use it only when I'm around to monitor it. The normal running of the stove is a piece of cake. Reliably accounting for unexpected combinations of failures and off-nominal conditions while running it 24/7 isn't.

I'll have to take a look at that modular i/o system...

 

[hyfire]

Smoke or heat detection in the hopper would be an excellent idea, you could even have a built in fire suppression system maybe co2?

 

[TheMightyMoe]

IT COULD CLEAN ITSELF!

 

[tjnamtiw]

I don't doubt that at all. I might do something also, but I'd likely use it only when I'm around to monitor it. The normal running of the stove is a piece of cake. Reliably accounting for unexpected combinations of failures and off-nominal conditions while running it 24/7 isn't.

I'll have to take a look at that modular i/o system...

Yea, definitely it would be a closely monitored system until one built up the trust level. Anything new is bound to have a few 'gotcha's' in it or 'darn, this would have been easier'. On the Quad's, it IS pretty simple but there are some checks and balances and sequence of events that has to take place for it to start up and run. That's where the ladder logic really shines. 'If THIS starts THEN start THAT' kind of sequences. You can also set flags to ensure that things have happened.

 

[hyfire]

I might buy the set up your talking about, for Xmas, Tjnamtiw would you give me some help with the programming?

 

[tjnamtiw]

I might buy the set up your talking about, for Xmas, Tjnamtiw would you give me some help with the programming?

Sorry but like I said in an earlier post, for legal liability reasons, I won't share my programming BUT, if you send me what you have written, I'd be glad to critique it for you and make 'suggestions' that you can use or chuck.

You have a completely different stove than mine, so you'd have to send me the schematic and some explanation of what you are trying to accomplish with the coding.

 

[hyfire]

I've given up on this project, far too complicated than I thought, and too many risks involved.