Spoke too soon-Econoburn fan issue

[shagy]

Econoburn made changes to the settings of the plc controllers and mechanical aquastats after they figured out that starting the fan on low fire using the aquastat was burning out the nimbus boards. The original intent of the mechanical aquastat was to cut power to the fan BEFORE the boiler reached overtemp. This is how we marketed the boilers, and this is how they were shipped from the factory - with the mechanical aquastat set to 180, and the overtemp alarm on the control set to 220. The switch on the fan is a new feature that I have not seen.

The fix described here by pybyr, from what I can tell, allows the boilers to use the original control settings (the settings that actually work) without worrying about premature failure of the nimbus.

cheers[/quote]

Ok, then I guess my setup is completely different.

My boiler came with a switch on the side of the fan housing. You can see it in the picture below, metal switch.

The wiring connections on the back of the boiler had a yellow jumper between the Blue/white for aquastat connection. I was told it was to make the fan run if the aquastat is not used. I removed the jumper and connected the aquastat.

I don't have storage hooked up yet so I have been idling the last few days. I can see that is not a good idea and my wood might not be dry enough. I will start a new thread with a picture of stack.

Very nice work. You did a great job setting up boiler. Very neat

 

[Piker]

I've given the "Neutral" side switching a thought and I don't think it's the right way to go. With the aquastat on the neutral side, should the neutral short out to ground before the aquastat, it will allow the boiler to continue to run bypassing the aquastat. I know that's a long shot but insulation melting off a neutral and shorting to frame(ground) would just be taking a different path back to the neutral bus. And if it happened in the right(Actually wrong) place, that aquastat is no longer doing its job.
On the otherhand, if the line side of the Nimbus were run through the aquastat and it shorted out, it would take out the fuse and shut the boiler down. Thoughts are welcome.

If I follow what you are saying... I think it makes sense. When I rewired this local test boiler for our customer, I did place the aquastat on the line side of the nimbus.

Still operating fine by the way.

cheers

 

[b33p3r]

Piker,
Switching the line side is definately the "Safe" way to do it. Hopefully the nimbus is robust enough to not be bothered by alot of on-off switching. Goosegunner recently bought an EB 200 and it came with a new controller, not the TC-33. It cycles differently than the TC-33 and it also shuts the fan off at set temp as opposed to the aquastat shutting it down. He has a thread near this one. Check it out and if you get any info on the new set up please be sure to let us know.

 

[mpoyneer]

Guys - I read the thread and I may have missed something but my problem is that the fan continues to run on high as my wood load is depleted, causing the boiler to act as a heat exchanger to ambient. This condition slowly lowers the temp of my storage tank inside the basement, so I needed to find a way to stop the fan once a lower (relative to setpoint) temp is reached.

Here are my thoughts and solution:

1) Timers are not a real solution for me, as I want the wood to burn completely out, leaving no chance for creosote.
2) My setpoint is 176 which seems to work well for now even with 500 gallons of pressurized storage.
3) I'm not getting the most efficient heat transfer due to my lines in the ground being 1" Central Boiler leftovers from my failed experience with Central Boiler's junk OWB that failed with multiple weld problems in less than 6 years of ownership.

Solution:

1) Wire the pump to run continuously regardless of what the controller is doing. In my outdoor Econoburn 150, it's wired directly to main power anyway, which facilitates using an ECM pump to make the system more efficient.

2) Install a normally closed relay in the fan circuit. The schematic shows the aquastat for high temp fan-kill already wired in the fan power circuit, so wiring an NC relay inline in the fan circuit will not cause undue stress to the Nimbus board since the aquastat opens the circuit when overtemp is reached.

3) Use the Alarm 1 on the TC33 controller to control energize the NC relay in the fan circuit at the Alarm 1 setpoint. The Alarm 1 contacts on the controller are wired to a pump relay and set at 110 from the factory for the indoor econoburn models. I'm simply setting it to 140, and when any temp lower than 140 is reached, the controller energizes the relay and opens the fan circuit.

I will wire a bypass and switch in the relay circuit, just to get fires started, but this solves my problem perfectly.

 

[mpoyneer]

One last note: another option would be to put the NC relay in the Nimbus power circuit, effectively shutting down the nimbus board when the low setpoint is reached.

Manual for the Automation Direct TC33 is located here:
http://www.automationdirect.com/static/manuals/processctrlm/tc33_manual.pdf

Thoughts?

 

[mpoyneer]

"cooling Fan" problem solved!

Omron LY2-AC110/120 DPDT relay wired in the power supply to the Nimbus (terminals "N" and "L")
- opens circuit on the alarm 1 setpoint via terminals 9 and 10 on the TC33 controller
- You have to make sure the Function for alarm 1 is set to "Low Alarm" by setting "A1Fu" to "0"
- pump must be wired directly to power and not controlled by the boiler controls

 

[pybyr]

"cooling Fan" problem solved!

Omron LY2-AC110/120 DPDT relay wired in the power supply to the Nimbus (terminals "N" and "L")
- opens circuit on the alarm 1 setpoint via terminals 9 and 10 on the TC33 controller
- You have to make sure the Function for alarm 1 is set to "Low Alarm" by setting "A1Fu" to "0"
- pump must be wired directly to power and not controlled by the boiler controls

I'm not sure I have followed the details of how your system is set up, but if you have a pump running all the time, what do you have in place for boiler return temperature protection at the beginning of and during a burn? Econburn's stock system switches the pumps to do that, turning off the system circulator and turning on the near/ bypass pump until the boiler is above a set temperature. Maybe you have other provisions in place- but you don't want prolonged periods where there is a fire but the heat draw prevents the boiler from attaining and remaining at relatively high temperatures.

 

[mpoyneer]

Pybyr - I have a Danfoss Thermic 3-way mixing valve w/140 deg element between the supply and return for that very reason.

 

[mpoyneer]

Pybyr - the outdoor boilers are wired very differently than the indoor models, trust me: I tried to setup mine using the schematic from the manual and it's nothing like the indoor units. Mainly, the pump is wired direct and always on.

When I installed the Omron L2Y DPDT relay (using alarm1 to energize the coil), I was able to use one side of one pole of the relay to open the power to the Nimbus module and kill the fan.
- The other side of the pole was used to light an LED switch that I wired in the coil side of the relay for a bypass to get a fire going past the alarm 1 setpoint.
- since this is a DPDT relay, I ran two additional wires from the other pole that I plan to use for pump flow control: one connected to the normally open side for low speed and one to the normally closed side for high speed.

These two modifications should make this boiler kick butt for use with storage tanks, for about $20 more for the relay, switch and some wire.

 

[mpoyneer]

I got home from work tonight to find the High temp alarm going off, and the controller showing 230 degrees. I opened the panel that covers the pump (outdoor models) and reached up and cracked the T&P valve and got a ton of steam. After getting everything settled back down, I noticed that my overtemp aquastat was set at 200, and I'm thinking that helped my overtemp issue but I wonder if the following contributed as well:
1) Danfoss 3 way mixing valve 150' away from the boiler, inside the basement near the storage tank
2) air in the system - would a small air pocket turn into a big problem at 180 plus temps?

 

[willworkforwood]

Your storage should have been able to take the load - is the pump sized correctly to do the job? What was the storage temp at the time the boiler was 230?. Also sounds like you don't have an overtemp loop - can you pipe overtemp into your power-out loop?

 

[mpoyneer]

Storage tank is 150' from the boiler, in my basement connected via 1" Central Boiler PEX (non-oxygen barrier). I had a check valve between the bottom of the storage tank T and the outdoor boiler, which was installed behind the Danfoss valve. I removed that tonight, and also found that my Aquastat was set at 200, so I dropped that down to 180.

The boiler to storage head pressure is at least 17 feet because of the 1" lines, so I need to replace them this spring/summer with larger diameter oxygen barrier lines.

My rant will end with the attached image: it's a type K thermocouple installed in my boiler...is there something wrong with this picture or is the end of the thermocouple supposed to be in the air/not touching the boiler steel? The image is of the top of the boiler, which the insulated thermocouple wires wrapping around the steel strap in the picture and the black tip of the thermocouple is in the air.

 

[NYEDGE]

Seems to me that your Danfoss valve should be by your boiler. The temperature of the water can drop during the 150' run.

During the second firing of my boiler I had a similar problem.
I had the boiler up and running and I had been baby sitting the new set-up watching everything like a hawk.
Well, I knew I couldn't dedicate that amount of time watching the boiler forever, so I ran out for a quick 20-30 minute outing to the store in order to ween myself
from watching the system run. When I returned my boiler had over-fired and the temp was at 220 and rising, and when I opened the dump valve steam came out.
I resolved the problem and found that some air that was still in the system and that caused the pump to "air-lock". Once the air was purged, I continued to monitor the unit
and it never did it again.

So, that being said, you may want to look at the pump and check to make sure that no there is no air in the lines, and that your air purging components are functioning.
I'm not familiar with your boiler controls, but doesn't your unit monitor the boiler temperature and shut down the primary air intake fans?
If it did shut the fan, then it sounds like your pump was not able to move the water from the boiler to storage, and you had no heat sink for the boiler hot water to disperse the raising temperature of the water.

 

[SnowTraveler]

In the air will give you a measurement error, should be tight to the steel. You still have a lag effect even with it tight to the steel. I put an additional thermocouple in a thermowell immediately at the boiler outlet piping of my econoburn and was amazed at how fast that one responds to temperature increase versus the one on the boiler jacket itself.

 

[b33p3r]

2 of my biggest complaints with my 150: 1) The fan not starting up reliably in low speed after the aquastat shuts it off. Sometimes blows the fuse.
2) I have a 20* difference between the aquastat and the thermocouple.
I originally talked to Dale about the temp difference and the digital temp readout being jumpy. He told me to bend the thermocouple "AWAY" from the steel? Snow traveler, your saying that is not good? I have not been able to run my 150 the way it was designed to run because of the temp difference. I basically own an Econo-more. Burn high fan or nothing. Problem with that control scheme is more idle time = more creosote. I think I'll start a new post to re-ignite the subject. No pun intended.

 

[goosegunner]

2 of my biggest complaints with my 150: 1) The fan not starting up reliably in low speed after the aquastat shuts it off. Sometimes blows the fuse.
2) I have a 20* difference between the aquastat and the thermocouple.
I originally talked to Dale about the temp difference and the digital temp readout being jumpy. He told me to bend the thermocouple "AWAY" from the steel? Snow traveler, your saying that is not good? I have not been able to run my 150 the way it was designed to run because of the temp difference. I basically own an Econo-more. Burn high fan or nothing. Problem with that control scheme is more idle time = more creosote. I think I'll start a new post to re-ignite the subject. No pun intended.

You should inquire about the new controller. My 200 has it and it seems to work well. It is no longer a nimbus board.

My thermocouple is actually in a well, not adhered to the top.

Gg

 

[SnowTraveler]

goose, both of the items you mention are very good, but do not benefit owners of older units. I inquired about updating the control package but did not get a reply. B33, I thought you had done a workaround as discussed in another thread with regards to the Nimbus and low speed restarts.

 

[goosegunner]

goose, both of the items you mention are very good, but do not benefit owners of older units. I inquired about updating the control package but did not get a reply. B33, I thought you had done a workaround as discussed in another thread with regards to the Nimbus and low speed restarts.

From my understanding the new controller would be a simple direct replacement.

Gg

 

[mpoyneer]

I bought my 150 in November of 2010 due to my Central Boiler POS leaking for the third time in six years inside the firebox. I'm going to call Mark/Dale on Monday and ask for a new set of controls, as I'm starting to have problems with my Nimbus board as well.

 

[b33p3r]

Guys check out the newer post "Econoburn customer Support". I've been speaking with Dale recently and the fix is near. In fact I'll be one of the test subjects. Jump to that post and read.