Post in 'The Boiler Room - Wood Boilers and Furnaces' started by wdc1160, Jan 3, 2008.
This is exactly what we are talking about, your using acronyms instead.
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What hardware are you actually using?
Not the same as nofossil's but his is similar
I think the big risk there is warping the bypass damper, but probably only if you leave the ash door open. I doubt an open bypass damper alone would produce enough heat in the firebox to do any damage, especially if you have water circulation. Your big hit is in efficiency and smoke, of course.
But glad to hear you lived to tell the tale all the same, barnartist. I've often wondered about that--halfway to work with nobody home and I'm wondering if I closed the bypass damper before leaving. That and worrying about the iron.
There you go, my arguement for a damper actuator, you don't have to be home to operate it.
That control board seems a little "over the top" in performance considering it's controlling a wood boiler. It looks like that board is suited for high speed automation.
That's a pretty serious damper, Bartman. It's made out of 1/4- or 3/8-inch high-grade plate steel. It takes some muscle to open and close it with a sliding lever mechanism. My wife can barely do it, and she's a tough Sicilian girl. You could automate it for sure, but it would take a pretty big motor, and I think it needs to slam shut for a good seal, which is critical.
I use a Technologics board as well. I'm using the TS-7260, which is about $150 if I remember correctly. It only consumes a couple of watts, has no moving parts, and includes a complete operating system and web server. When you look at the real-time display on my site, you're actually getting a web page from my TS-7260 controller.
As a full-blown computer, it gives me a lot more programming capability than a PLC. For instance, it does the datalogging that allows me to create the graphs that started this thread.
It's overkill if all you're doing is controlling a wood boiler, but it's a pretty nice platform if you want to experiment or if you're controlling a more complex environment.
Leverage is a wonderful thing. About an hour ago I bought the damper actuator in the link I posted in the "Damper Control" thread that I started, it's programmable and seems to be the most versatile unit I have seen. Let's see what it looks like in my hands, I'll report back on it's power. For me, I don't need much in the line of torque but it may be of use to you guys with the big mechanical dampers.
How do you interface it with relay/drivers?
I missed what you said about a damper.
I don't recomend the board I have to anyone else. I have only worked with it for 16 days.
I got it because I didn't know what the second reincarnation of the board might be used for. Or, if it would have other jobs.
Over the top in many ways is subjective. Even 1/3 the board that I have could be over the top -depending on what it needs to do.
What i know to be true is that whatever board you choose it proabably needs some type of logging combined with easy interface -- is what separate this from the microcontrollers, older controllers like the TI/GE/Siemens.
No logging and no interface means more difficulty in seeing problems. Moreover, I had planned on allowing others to see my controller card in action online.
But, I didn't want to run a barebones web server on it - since good crackers could break into my network with little effort w/o the proper security.
So I don't think it would be overkill for that, but like you said that isn't just controlling a boiler. That is controlling a webserver, logging, 10 other pieces of IO- eventually.
As I posted above
The Technolgics board comes with 2 channels of analog and 30 channels of digital I/O onboard. I only use 16 bits of onboard digital I/O, but I added two TS-9700 8 channel A/D cards and a DIO-64 64 bit digital I/O card. The Technologics boards use the PC-104 bus, so you can stack cards together to get whatever functions you need.
The DIO-64 has enough chops to drive relays directly. For the onboard DIO, I use an external relay driver IC.
Most of my relays are cheap 12V automotive jobs - about $1.50 each. I also have some 24VAC relays that are more expensive - about $3 each.
For anyone who hasn't played with relays, they're great. Essentially an electrically operated switch, or more commonly, a pair of switches that are a operated simultaneously. Since I don't understand electronics very well, I use them for everything.
The photos below show the relay panel as well as the controller. The picture on the right is older and more out of date. Check out the classy plywood enclosure!
I bet everyone wishes they didn't know as much about electronics as you
Holy cow! That's one heck of a control system! Being a licensed electrical contractor, I can't exactly confirm that your application conforms to the NEC...........but it's cool.........and I thought I was a control freak!
With the Series 1 PLC, I can control my 120V loads, 24V loads, have 120 or 24V inputs to and from the same PLC, with no additional relays. For my application, I don't need logging, I don't need to see where every BTU is going , but I do want reliability. My initial setup, which will include monitoring stack temps, water temps, outside air temps will first take some programming trial and error, but once completed, will be set and forget.
The damper actuator(s) in my system will serve 2 functions, 1 possibly in the oil boiler flue to remain shut when under no-fire condition. When burner wants to fire, damper opens, when reaches full open closes circuit to fire burner. Second damper to actuate shutter on wood combustion air blower, to shut in no-demand mode to let boiler idle, and second function to close if flue reaches to high of temperature, (run away fire, or chimney fire).
It's all low voltage - nothing above 24vac on the board or in the picture. The high voltage stuff is done right - armored cables and so on.
I don't have any dampers at all, but I've considered adding on to the oil exactly as you describe.
There's a couple of people selling on eBay actuators, I bought one last night for $35 with shipping(20+15). The shipping was a little high, but the price is still a steal for these things. There's another guy selling 1 1/4" motorized valves reasonable also, I'm thinking of incorporating those into my system as well. Wood boiler on first start, get's to temp, valves open putting boilers in series, fire goes out, valves actuate back to oil mode...........I'm getting goosebumps hh:
If you look at my plumbing (link in signature below) you'll see that I have it set up with the oil and wood in parallel, each with its own circulator. There is no need for changeover logic or valves - each controller operates just as it always has, and turns on it's circulator just as it always has. As long as the oil responds to a thermostat setting lower than the wood, it's simple and painless.
Of course, I added many layers of complexity just because I can ;-)
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