New Econoburn questions about chimney/smoke/residue

[goosegunner]

GG: you've definitely got a new and different control panel that has not been seen before.

Does your manual have a wiring diagram or diagrams that go with this new DFD control?

If so, I'd be intrigued to see what it consists of and how it is connected.

I'd also be interested in hearing a description from you of how the fan speed behaves-- in other words, what do you hear/ notice as the actual temperature reaches the set temperature (is it a sudden ramp-down in speed, or is it gradual....) and what happens if the measured temperature drops below the set temperature?

No the wiring diagrams in book are the old ones.

This is how it performs

1. High speed fan until 4 or 5 degrees before digital set point

2. Low speed fan until set point reached.

3. Fan off at set point

4. As temp drops low speed starts, if temp continues to decline from load the High speed kicks on at about 10 degrees below set point.

5. Periodically the High speed kicks on for about 5 seconds to fan coals even if boiler is at set point or above.

6. I currently have digital set point at 175. The highest overshoot I have seen is 181.

7. The Aquastat is set at 215 for over temp to kill fan.

My boiler also has a metal toggle witch on fan housing to stop fan.

I checked this morning and it does gasify in low speed with a slower purple/orange flame

gg

 

[goosegunner]

Pybyr, I was talking with Goose this A.M. There is no new wiring diagram as of yet. Just an insert stating it is the new controller. he has his set temp at 175*. The fan will be in high speed until approx. 170. Then it ramps down to slow speed. Once the temp goes approx 5* above set point(180), the fan shuts off. The thing that struck me as odd, and I specifically asked Goose about it, is when the temp bleeds back down a few degrees under set point, the fan starts up in "slow" speed. It does not go into high speed first then ramp down.
His aquastat is set at 215* per Dale so it is definately the controller turning the fan off. I'm also interested in seeing the new wiring schematic.

Couple of things to clarify

The fan shuts off at the digital set point. Depending on the wood load/ heat load it will over shoot some with out fan running. Highest I have seen is 181.

The Aquastat came preset to 215. Dale said I could be set lower if I choose. I have left it at 215 so far but will probably lower since I am running temps much lower anyway.

gg

 

[Piker]

Yep... definitely a new control and not just a reprogrammed older version. You stated earlier that the unit still gasifies on low fire... And also that the fan shuts completely off at idle... this is definitely a plus. I would feel pretty comfortable about the control strategy at this point.

The periodic pulsing of the fan I bet is an attempt at preventing excess gas from accumulating in the upper chamber that can cause backpuffs or explosions inside the boiler. Not sure how this will effect overall efficiency, but it seems like it might produce a few more btu's from the upper chamber where you have low efficiency - low temperature combustion as opposed to the lower chamber where the high efficiency combustion takes place.

Anyways... it seems like they've gotten back to their original control strategy, just with a different controller. If the low speed fan start doesn't cause reliability issues, I'd say you're good to go.

cheers

 

[goosegunner]

Yep... definitely a new control and not just a reprogrammed older version. You stated earlier that the unit still gasifies on low fire... And also that the fan shuts completely off at idle... this is definitely a plus. I would feel pretty comfortable about the control strategy at this point.

The periodic pulsing of the fan I bet is an attempt at preventing excess gas from accumulating in the upper chamber that can cause backpuffs or explosions inside the boiler. Not sure how this will effect overall efficiency, but it seems like it might produce a few more btu's from the upper chamber where you have low efficiency - low temperature combustion as opposed to the lower chamber where the high efficiency combustion takes place.

Anyways... it seems like they've gotten back to their original control strategy, just with a different controller. If the low speed fan start doesn't cause reliability issues, I'd say you're good to go.

cheers

I haven't been able to determine how often the High speed (Flush I will call it) happens. I Think it depends on the heat load on the boiler. I don't recall it doing it when the fan is on low speed. Seems to me it has only happened when the boiler is up to set point or above and is holding for a while due to no temp drop from lack heat load demand.

I could be wrong though as it is in the shed.

I am hoping the low speed starts are fine, I guess only time will tell.

gg

 

[pybyr]

GG- 2 questions, if you don't mind checking/ reporting:

1) in your list above, #4, when it turns the fan back on at low speed, can you detect a brief (only a second or two) "spin-up" before it settles into the low speed? That'd suggest that the switching is happening on the supply side of the speed control (if it is still the Nimbus) which is a good thing

2) does it shut the blower down completely at some point after the fire has gone out? The earlier Econoburns require either manual shut-off or some sort of separate/ additional control to accomplish that.

 

[goosegunner]

GG- 2 questions, if you don't mind checking/ reporting:

1) in your list above, #4, when it turns the fan back on at low speed, can you detect a brief (only a second or two) "spin-up" before it settles into the low speed? That'd suggest that the switching is happening on the supply side of the speed control (if it is still the Nimbus) which is a good thing

2) does it shut the blower down completely at some point after the fire has gone out? The earlier Econoburns require either manual shut-off or some sort of separate/ additional control to accomplish that.

1. It does not spin up in high speed.

2. It does not shut the blower down if the boiler is out of wood. I am going to need some help with wiring some type of controller to do that when I get settled in with this thing.

With the fan switch on the side of the fan housing it should be easy to replace or add some type of timer. Any ideas?


I also have to figure out a way to control my primary manifold pump in my other garage. Right now when I am running with storage bypassed if the boiler goes below the danfoss temp 140 my primary/ secondary pumps could be running but unable to circulate because the return side of danfoss would be closed.

gg

 

[b33p3r]

Goose,
I know I've read in here that some people use a mechanical timer to shutdown their fan after so many hours. The "so many" is determined by their experience of their max burn time. Like the aquastat it's put inline with the fan. But you'll have to do a little more homework since you have the new controller.

 

[goosegunner]

Goose,
I know I've read in here that some people use a mechanical timer to shutdown their fan after so many hours. The "so many" is determined by their experience of their max burn time. Like the aquastat it's put inline with the fan. But you'll have to do a little more homework since you have the new controller.

I found this post about shut down timers that pybyr wrote up. Hoping I can get something set up like that.

post 9

https://www.hearth.com/talk/threads/67470/


The biggest issue I have right now is figuring out a way to shut down my primary manifold in the garage if the boiler's temp in shed drops enough to close the Danfoss return. I am afraid I will wreck the pump if the water can't move. It just happened tonight. I misjudged how long the wood would last and I came home and boiler was down to 139.

gg

 

[SnowTraveler]

I use an ATC electronic time delay relay mounted in an enclosure adjacent to my boiler, on the wall. I wired the contacts into the Nimbus board feed, several years ago, to time off the fan after several hours of burn. They are for industrial applications, so should last decades. They can be bought on ebay pretty cheap, as can all sorts of industrial controls.

http://www.automatictiming.com/ATC/PDFs/Timers_atc/319.pdf