Englander 55-SHP-10 DIY Control System - Home Automation Questions

computeq

New Member
Nov 8, 2019
4
Maine
Hello,

My name is Steven and im new to the forum.

I am a home automation nut i have designed all my own custom controls for all over the house from garage doors, to my thermostat system to control my boiler, a homemade irrigation system for my wife's garden boxes, so on.. This year i installed an existing pellet stove into our home to replace our wood stove and i was hoping that thermostatic controls would be enough for me to control the heating of our home with said stove. However even with a thermostat hooked up the stove throws to much heat in between heating cycles and over heats the house. To that end i've decided i want full control over the pellet stove and its operations so that i can remotely control its heat output via the homes existing thermostat system.

I have a few questions about the operation of my englander 55-SHP-10 stove in an effort to build the custom controller board for it.

1. From my research thus far it appears that all the major components of the stove "augurs blower motors igniter" are all 110V AC though i do see a transformer on the original control board. My assumption here is that this is a dc regulator for the board itself. My question here is what about all the safety switches are these 110? as well AKA the vacuum switches and the hopper switch?

2. Does anyone have a true electrical schematic of the stoves operation ? I need to figure out which safety switches are inline with which components of the stove as i dont want to compromise the safety systems of this stove while installing a custom controller.

3. Does anyone have any information about the duty cycle and timing of the top auger of this stove and or blower motor voltage speeds or am i going to have to just test and check till i find proper settings that work?

4. Is there anyone out there that has experience with building DIY controllers for pellet stoves in general that i might draw off some of their experience.

Thank you

Steve
 

Ssyko

Minister of Fire
Nov 6, 2017
2,450
Lorraine NY
Wow you have chosen quite the task. Of all the stoves the englander is one of the most difficult. First the processor software is proprietary to the pcb board mfg’s along with the schematics. Englander doesn’t have access to it. Upper auger timing is based on a 16 sec cycle. And varies from stove to stove.(i can break down the 25pdv and 25pdvc when i get to my PC. The transformer is a step down 120vac to 7.5-15vdc. Pic controls the optos that trigger triacs to isolate 120vac to the lower dc voltage.The thermister is used as a high temp, low temp, fan control (another microcontroller involved there) vac switch is 120vac direct line to motors.

My question is what heat setting is the stove set to that your getting to much heat on a tstat?
 

computeq

New Member
Nov 8, 2019
4
Maine
Wow you have chosen quite the task. Of all the stoves the englander is one of the most difficult. First the processor software is proprietary to the pcb board mfg’s along with the schematics. Englander doesn’t have access to it. Upper auger timing is based on a 16 sec cycle. And varies from stove to stove.(i can break down the 25pdv and 25pdvc when i get to my PC. The transformer is a step down 120vac to 7.5-15vdc. Pic controls the optos that trigger triacs to isolate 120vac to the lower dc voltage.The thermister is used as a high temp, low temp, fan control (another microcontroller involved there) vac switch is 120vac direct line to motors.

My question is what heat setting is the stove set to that your getting to much heat on a tstat?
1 1 lowest possible

so perhaps im taking this a bit to simply but the timer cycle can be accomplished with code because the auger is either on or its not so that parts simple.. by creating a new controller i would be removing their board all together so what im mostly driving at is that 7.5 step down to DC is that voltage used on any of the components in use or are they all 110 ac?

my idea is to utilize either a raspberry pi in which i can control relays that can actuate the combustion motor and the two augers as well as the igniter so to me that part seems pretty straight forward... I just need to know if the safety switches are inline on the 110v power to each device that is being controlled or if thats all being handled by micro controllers. Ive seen other videos where people have used 110 switches to accomplish this on the englanders however i fear they have bypassed all the safetys to do so.
 

Ssyko

Minister of Fire
Nov 6, 2017
2,450
Lorraine NY
they have done the hard work. use a wifi/programable tstat with a swing and fine tune the stove to do what you need ie heat the house efficiently/effectively? not to mention if you have a fire the insurance co. will skate on paying because the system you build has not been approved by UL. but if your gonna do it anyway, i will dig up the heat settings/auger cycle times after dinner ;) oh the dc voltage is for only board components
 

computeq

New Member
Nov 8, 2019
4
Maine
I would appreciate those settings please

I have a few more questions if you dont mind.

Assuming i wish to continue
1. The variable speed of the heat exchanger motor.. How is this controlled currently with a Triac? or just a potentiometer?
2. Are the safety switches inline on the same 110 supply that controls those specific components?

I already have a thermostat hooked up to the current control board but it seems like it does nothing whether its on or off. The stove still continues to pump out heat to fast for the house to ever start cooling. so the temp in the house just slowly keeps climbing till i shut it down. Do you have any recommendations on adjustments that i could make to try and tame down this stove with out having to build a new controller lol i dont really want to i just am running out of ideas since its on its lowest setting and still over heats the house.

Thanks so much!
 

Ssyko

Minister of Fire
Nov 6, 2017
2,450
Lorraine NY
#1 the 28 pin pic18f2420 controls everything it has a Internal oscillator supporting 31 kHz to 8 MHz. and if you try to read it it has watchdog security so it trashes the chip and renders it useless.(don't ask me how i know)

#2
25PDV_PDVCWire.jpg

now on to the thermostat issue. did you remove the jumper/shunt from J3 on the bottom of the control board when you put the wires in for the tstat?
 
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computeq

New Member
Nov 8, 2019
4
Maine
Hi I did remove the jumper on J18. I have discovered that i have to turn the low feed rate down all the way to 3 this balances out the house much better when the thermostat is not calling for heat. Its unfortunate that only the feed rate is impacted when j18 is not connected and not the heat exchanger as well to slow the fan . I had to play with the low feed rate quite a bit because i had it all the way down to 2 and it kept burning itself out due to the lack of fuel being supplied. Im going to monitor it for a week at 3 and see if it keeps flaming out or if it keeps running