Okofen problem - PE1 thermal safety

[dhaulagiri]

I may soon convert the first one: a resident of my village, who had my contact details by the brand.

He called me the other day to ask me a few questions. I realized how baseless some of them were. Yet, I admit, I asked myself the same. I think of the classic "My current boiler is 25kW. We recommend a 15kW boiler: will I be cold?". I would really like to understand the intellectual journey that puts us in a position to invest a significant amount in a heating method that we think is not heating enough.

I invited him to see my installation. The hardest part will probably be not to get drunk, as carried away as I may be by my passionate explanations.

To hang on to the subject of the wire, I told him that I had read your experiences at length and that the absence of major problems on your various installations (6 years for Did!) Had reassured me. The problem in question here, which is very unpleasant for Aurelwine, is of minor importance. Knock on wood so that this year does not reveal more important

[dhaulagiri]

By the way: Aurelwine, wouldn't you have taken a picture? Yes, I know, on 31/12, when we have no heating and we have guests, we have other things to do than pictures. But I am a "visual", me ...

[Did67]

As we are discussing here, I just want to wish you a happy new year, with a special thought for those of you who advised me just a year ago and thanks to whom I am very warm today without gas, without neither oil and (almost) without nuclear. Yep, you still have to light the casserole ...

A+
Dhaulagiri

Hail the "climber of the South"!

Happy New Year too, with this "info" on the progress of the cogeneration pellet boiler at Okofen, which will enter pre-production tests:

http://www.okofen-e.com/de/okofen-e/oek ... izung.html


Some elements taken from the project site (in German):

- the power of the pellet burner is 12 kW, the production of 11 kW thermal + 1 kW electric ... For the moment, only this power is developed (the Striling of 1 kw was developed by another company and is already sold: see Microgen)

- in a detached house, this could therefore produce around 1 kWh at 500 kWh electric (in my case, 2 m² at around 000kWh / m².year for heating, i.e. 200 kWh thermal, this would make 100 kwh electric)

- so in winter, we can charge an electric car while heating ...

- what is interesting is that, unlike photovoltaics, this occurs when electricity needs are also at a maximum

- the cost of the pre-series (which will enter into a "full-scale" test shortly) is estimated at 23 to 000 euros for the complete kit ex works including tax (including silo, hydraulics, etc.). The buffer is integrated.

- no maintenance planned on the stirling; annual "normal" maintenance on the SMART

- automatic cleaning of the stirling exchangers has been developed

- the size is not significantly larger than that of the classic SMART


Without a subsidized feed-in tariff (or specific subsidies for the "cogeneration" purchase) it will be difficult to amortize!

[manet42]

These are two ex-colleagues that I "contaminated", an Okofen and a KWB, the installer has changed supplier in the meantime (business reason! Network restructuring?).

Still, the stuck pellet of Aurelwine calls me ...
I measured with the ohmmeter:
Unburned pellet, 10 Mohms, non-conductive.
Charred pellet (ashtray is left in the rain, wet), 8 to 10 kohms, not very conductive.
If specialists can explain?

JC

[roy1361]

Hello,

Isn't it rather because the pellet jammed the rotation of the engine that it tripped?

[Did67]

I just think that aurelwine's expression "blow the lead" is abusive.

Undoubtedly like the majority of us, it is about a differential circuit breaker at 30 mA: the pellets, even weakly conductive, caused a leakage current towards the "body" of the boiler, therefore the ground. .

So your resistances are compatible, if I'm not mistaken, with a leakage of more than 30mA.

I would have to calculate the U = RI. Let's go: so I = U / R = (220 / 10) in A = 000 mA (ah no ...). With 22 we frieze (8/220) = 8 mA

With the uncertainties, this must do it!

[manet42]

OK, I hadn't thought of the 30mA circuit breaker, not at home on the heating circuit.
It remains to be seen whether the pellet was charred and where exactly it was stuck.
I "quibble" but in winter, we have time since the boiler "runs smoothly" there is nothing more to watch

For Roy, if the engine stalls, there is a safety device that stops the boiler without cutting the power in the house. It happened at my place.

[Did67]

If I had to do it again, I would not put 30mA on circuits like taken in the sub-osl, garage, exterior ...

I have outside a series of bollards in an alley, one serves as a refuge for forumis who settled there (they must like stainless steel and electro-magnetic fields, will understand ants!); suddenly, occasionally, general disjunction!

I am going to switch to 12 V, with a transformer which "will separate" the circuits, with the exterior in 12 V without connected earth. So the 12 V protects me and suddenly, more "measurement" of the leaks ... And I will put LEDs ... A little work, but will avoid breaking out and saving (NB: on the internet, in the " camping-caravanning "from some light bulb sites, there are 12 V on E27 or E14 bases - if anyone is interested)

[manet42]

(they must like stainless steel and electromagnetic fields, will understand the ants!)

B.WERBER has written three books to understand ants:
-Ants 1991.
-The day of the ants 1992.
-The secret book of ants 1993.

To read.

JC

[dedeleco]

Good evening Okofen.

If specialists can explain?

a charred piece, if it heats a little, sees its resistance decrease quickly and therefore the current exceeds 30mA.
The charred stuff gives nice resistances not very reliable sensitive thermometers. In addition, the resistance measured is a function of the surface in contact with metals, and if this surface is small with Ohmeter tips, the resistance is increased.
In addition by removing the jammed granule, it was cracked and the resistance increased !!!
All these reasons make the current stronger than we imagine afterwards.
A very wet pellet is much less resistive, especially if for lack of luck a hygroscopic crap has stuffed it, like grains of salt, etc.
In fact, it is definitely out of luck.
So the physics of this avatar is complex.

I have outside a series of bollards in an alley, one serves as a refuge for forumis who settled there (they must like stainless steel and electro-magnetic fields, will understand ants!); suddenly, occasionally, general disjunction!

funny, for me it's my mailbox that they love, and also the soil of new plants planted to the point of killing these shrubs by cutting the contact between the roots and the soil.
There is even a rat that eats my envelopes (good fish glue).

In fact, the ants adore ready-made nests, sheltered from the sun, in the dark, humid, accessible where they lug from far away full of soil for their nest of cocoons, very quiet. The moist soil conducts the current well.
Is it better than rats that cut their teeth on electrical wires or pierce garden hoses?

These terminals are therefore ideal for them, like my mailbox.