Ämne: Nibe F1255-6 PC: saving energy

[Floris]

Hej,

Sorry for posting in English.

We have a Nibe F1255-6PC, connected via Modbus to Home Assistant. I use the SG ready functionality when solar power is available and the holiday functionality to save energy when we are away for more than a day.

Question 1
Is it possible to do the 'periodic increase' of the temperature of the tap water (against legionnaires' disease and other unwanted growth) when solar power is available? I understand te heat pump will not wait longer than the selected period, but doing it sooner when solar power is available would be nice.

Question 2
Sometimes the supply pump is running, while the compressor and brine pump are off. What is happening at that time?

Question 3
Sometimes the brine pump runs at 1%. Why is that?

Tak

[Carl N]

1. I don't think so, but you can schedule it to a special time on the day. If you select at 1200 it should be when solar power usually is avaialble.
2. It's like this when it is not in summer mode, only in summer mode supply pump is off.
3. I'm not sure, what is the temp diff on the cold side when this happens?

[Floris]

Thanks!
1.
I see. The solar production differs from day to day, of course. Do you perhaps know if my observation is correct that when you change the frequency, it starts heating right away? As if there is no memory of when the last time was?
If not, it would be able to change the schedule externally, whenever there is solar power available.

2. It's like this when it is not in summer mode, only in summer mode supply pump is off.
Ok.

3. I'm not sure, what is the temp diff on the cold side when this happens?
About 3 degrees Celsius.

[Carl N]

1. You can use a excternal signal for this.
Use the function "activate temp lux" and set the temp in 5.1.1 to the luxury temp for periodic increase.
Side 28
https://www.nibe.eu/assets/documents/16708/231531-6.pdf

If you change the settings, I think it starts from there.

3. The diff should be around 3 deg, thats the reason...

[Floris]

1. You can use a excternal signal for this.
Use the function "activate temp lux" and set the temp in 5.1.1 to the luxury temp for periodic increase.

Thanks, but I don't think I understand.
I can increase the luxury stop temperature from 54 °C (current setting) to 58 °C (the value for periodic increase), and start it by setting the system to luxury. But will that stop the system from periodically increasing the temperature by the schedule anyway?

[Carl N]

Thanks, but I don't think I understand.
I can increase the luxury stop temperature from 54 °C (current setting) to 58 °C (the value for periodic increase), and start it by setting the system to luxury. But will that stop the system from periodically increasing the temperature by the schedule anyway?

No, you have to turn of the periodically increase of temperature if you use the luxury temp for this.

[Floris]

I understand. I don't think I want to take the risk of turning off periodic increase in the heat pump itself and rely on an external schedule.

Thanks Carl! You have been very helpful.

[Floris]

Hej,
Sorry for posting in English.

I have some updates and a question.

I've mostly solved the goal of running the heat pump as much as possible on the power from our solar panels.

I've connected a Shelly relay switch to inputs 11 and 12 (44878 SG Ready input A), and a fixed wire to 9 and 10 (44879 SG Ready input B). With that combination I can switch between 'Low price mode' and 'Overcapacity mode'.

With Modbus (via Home Assistant https://www.home-assistant.io/integrations/nibe_heatpump/) I switch the 48282 SG Ready heating and 48284 SG Ready hot water values on and off. I use that to effectively switch off SG Ready completely (and disable 'SG Ready heating' when the expected temperature at night is high enough that we won't need heating).


The question I have is, how do I get the heat pump to act on 'Overcapacity mode' if the hot water temperature is higher than the set minimum temperature. In this graph from today, 'Overcapacity mode' is switched on, but not acted on at all. It was yesterday, as you can see from the higher temperature at the left side of the graph.
This means, the heat pump might switch on this night, while there was plenty of solar power available at day time.

[Carl N]

Can't you use the external connections, AUX (AA3-X6:), for this?
Just use Activate luxury temp in meny 5:4.

[Floris]

Just use Activate luxury temp in meny 5:4.

Thanks! I've configured it so luxury temp is enabled also when enabling SG Ready 'Overcapacity mode' is enabled. That works.
I find it strange though that this is required for 'Overcapacity mode' to actually use all the power it can.