The biggest problem seems to be that, no matter what the flow temp setpoint is, the minimum compressor frequency will be limited by the outdoor temperature. It doesnt seem like there are any settings that can be changed to work around this. This then might have more or less impact, depending on the characteristics of your house and heating system.
About the post defrost response, @gekkekoe ‘s AA solution attempts to mitigate it, but there might be a limit on how much we can “fool” the FTC.
I dont have graphs for your temp ranges, as i only started using gekkekoe’s AA couple of days ago, but here is one for colder temps. (I am still tweaking the settings)
I edited the image to include the feed and return temps. You can see that the Auto adaptive system is adjusting the flow setpoint (the blue line in the first graph), according to the return temp. But like i said, none of that will fix the minimum frequency vs outside temp issue, it can only alleviate, at most.
Looking at the graphs, it is pretty clear it is being based on return temp. Maybe it is because i have buffer tank (1 zone), but the docs seem to confirm my observation
Calculate Target Flow: The final target flow is calculated based on the real-time return temperature. Calculated Flow = return_temp + target_delta_t
But this itself would not mitigate cycling as it’s not the condition the FTC would use to stop the outdoor unit
It seems that coincidentally raising the flow based on the return keeps the Setpoint vs. Actual within the FTC limit
Didn’t see that at first, I’m still using built in advanced AA on FTC6 v20.01.
Did you try to power cycle unit? Assuming it’s currently on constant flow control mode, does it modulate on compensation curve mode or room temp mode?
Also the flow temperature doesn’t seem to increase very much, unit on it’s limit? Although the same on lower outside temperature. How old is the system?
Not recently. Yes, it is on flow control mode. Not sure what you are asking exactly, it modulates in all the modes, just more or less depending on outside temp.
The unit is close to the limit below -20, but that’s not the reason for what you see. The max temp was limited to 45C, and you can see that it was actually modulating down to keep it in check. I have been increasing the max flow temp slowly, to see what is actually required and how it behaves.
It’s 8kW, R32. It eventually stabilises around that, but the the house is old and leaky. Even stopping for the DHW cycle, is enough for the house to lose 0.5C in -10C weather
There’s a very strong indication that the pud/puz units have certain frequency based on outside temp. I have seen folks getting higher frequencies when it gets colder, it won’t go below. Only ‘fixable’ via fake NTC I guess.
Hi everyone, I have a 2-wire shielded cable (bipolar) running from my Ecodan to my M5Stack Lite.
Is it possible to use these two wires exclusively forTX and RX communication, while powering the M5Stack from an external power supply? Or is it mandatory to connect it also to the V+ and GND pins of the Ecodan?
ok Cool, thank Gekkekoe. I just wanted to get the Atom closer to the wifi router as the connection sometimes drops and using server mode it’s an issue.
It would be really good to have a standard way of wiring in something to allow control of the outdoor temperature sensor.
Doing that would allow decoupling of the minimum compressor speed from the outdoor temperature.
The fan speed also seems to be dependant on the outdoor temperature so control of that could also allow quieter operation (on my unit the fan noise is much louder than the compressor and it under around, I think, 6°C it jumps up to full speed).
I believe defrosting is done from different sensors so wouldn’t be effected badly by not having the correct outdoor temperature. However I’m not sure if there is anything else bad that could happen (apart from restricting the heat output of the unit).
