Mitsubishi Ecodan &...
 
Notifications
Clear all

Mitsubishi Ecodan & Raspberry Pi automations

91 Posts
11 Users
34 Reactions
11.4 K Views
(@kev-m)
Famed Member Moderator
5562 kWhs
Joined: 3 years ago
Posts: 1299
 
Posted by: @derek-m

@kev-m 

Hi Kev,

I can't remember if it was in the Ecodan manual, or some other manufacturers manual, where the instruction was to set the weather compensation parameters before enabling auto adaptation.

I would expect the control algorithm, within the FTC controller, to initially set the water flow temperature dependent upon the outdoor air temperature (weather compensation) and then fine tune the control to achieve the desired indoor temperature (auto adaptation), with both working together.

The 'learning' capability I suspect is the self tuning aspect, where the controller adjusts the internal control parameters to accommodate the response times of your particular system. I would have expected these parameters to be stored in non volatile memory, so should not be changed by  a power shutdown. It is possible that they could be changed by a full reset, or the installation of updated software.

If you find any further details I would be interested to know.

As I said, I'm only going by what others said on a Facebook group, which probably means it's a load of rubbish!  I'm going to try auto-adaptation when I get back from holiday as I have a Mitsubishi thermistor.  I'm interested to know what it does.


   
mjr and mjr reacted
ReplyQuote
(@ajdunlop)
Eminent Member Member
255 kWhs
Joined: 2 years ago
Posts: 17
 

Am I correct that the 'auto-adaption' feature applies to when the FTC6 main controller is set to room temperature mode or is it just if a wireless controller is used?

I set our office's main controller to room temperature mode and it straight away went for a 50 degree flow temp overheating the place. I had set it up to use the WC curve with a max temperature of 38 degrees so it looks like it was ignoring that. I don't know if it would over time realise that was too aggressive and adapt down but I wasn't willing to subject my colleagues to that to find out.

I wonder if it would be possible to limit it by changing the maximum flow temperature in the Operations Settings menu.


   
ReplyQuote
 mjr
(@mjr)
Prominent Member Member
1941 kWhs
Joined: 2 years ago
Posts: 304
Topic starter  

Posted by: @ajdunlop

Am I correct that the 'auto-adaption' feature applies to when the FTC6 main controller is set to room temperature mode or is it just if a wireless controller is used?

"Auto adaptation" is used when both the FTC6/5/maybe-others main controller is set to a room temperature and DIP switch SW1-8 in the big control box is set ON.

Posted by: @ajdunlop

I set our office's main controller to room temperature mode and it straight away went for a 50 degree flow temp overheating the place. I had set it up to use the WC curve with a max temperature of 38 degrees so it looks like it was ignoring that. I don't know if it would over time realise that was too aggressive and adapt down but I wasn't willing to subject my colleagues to that to find out.

That's basically my experience. I can tell you the next stage of what happens, too: it overshoots, then lowers the flow temperature right down, so the room temperature falls and then it goes for a high flow temperature again. I let it do that for a day once and it showed no sign of learning anything from its mistakes.

If I get the area up to temperature another way (using curve or flow modes), then auto-adapt seems able to hold a temperature OK and it can do one thing that I've never seen in the other two modes: pump water around the heating loop for fairly long periods (30+minutes) without running the heat pump itself until the flow temperature drops too far. This seems to be useful in winter where heat is lost faster and so the emitters can keep warming the rooms, but it seems a waste of energy in spring and autumn. The ecodan doesn't appear to count the (admittedly low) pump power as part of HeatingEnergyConsumed, which seems a bit naughty and gives flattering heating performance stats alongside more realistic overall ones.

 

Posted by: @ajdunlop

I wonder if it would be possible to limit it by changing the maximum flow temperature in the Operations Settings menu.

It looks like it should. You could also reduce the "thermo diff adjust upper limit" to stop it overshooting so far, but I wonder if that would be at the cost of more cycling in mild weather.

The FTC manual also says that there's a "Fast" mode which is even more aggressive and expensive. I shudder to think how that behaves!


   
ReplyQuote
(@kev-m)
Famed Member Moderator
5562 kWhs
Joined: 3 years ago
Posts: 1299
 

Posted by: @mjr

Posted by: @ajdunlop

Am I correct that the 'auto-adaption' feature applies to when the FTC6 main controller is set to room temperature mode or is it just if a wireless controller is used?

"Auto adaptation" is used when both the FTC6/5/maybe-others main controller is set to a room temperature and DIP switch SW1-8 in the big control box is set ON.

Posted by: @ajdunlop

I set our office's main controller to room temperature mode and it straight away went for a 50 degree flow temp overheating the place. I had set it up to use the WC curve with a max temperature of 38 degrees so it looks like it was ignoring that. I don't know if it would over time realise that was too aggressive and adapt down but I wasn't willing to subject my colleagues to that to find out.

That's basically my experience. I can tell you the next stage of what happens, too: it overshoots, then lowers the flow temperature right down, so the room temperature falls and then it goes for a high flow temperature again. I let it do that for a day once and it showed no sign of learning anything from its mistakes.

If I get the area up to temperature another way (using curve or flow modes), then auto-adapt seems able to hold a temperature OK and it can do one thing that I've never seen in the other two modes: pump water around the heating loop for fairly long periods (30+minutes) without running the heat pump itself until the flow temperature drops too far. This seems to be useful in winter where heat is lost faster and so the emitters can keep warming the rooms, but it seems a waste of energy in spring and autumn. The ecodan doesn't appear to count the (admittedly low) pump power as part of HeatingEnergyConsumed, which seems a bit naughty and gives flattering heating performance stats alongside more realistic overall ones.

 

Posted by: @ajdunlop

I wonder if it would be possible to limit it by changing the maximum flow temperature in the Operations Settings menu.

It looks like it should. You could also reduce the "thermo diff adjust upper limit" to stop it overshooting so far, but I wonder if that would be at the cost of more cycling in mild weather.

The FTC manual also says that there's a "Fast" mode which is even more aggressive and expensive. I shudder to think how that behaves!

I tried auto adaptation but stopped it after a few hours of 55 degree flow and a huge jump in energy consumed.  As you say (and did some time ago too to be fair!) it's very aggressive when heating up a cooled down house. I may try it again when it's not so cold. 

 


   
ReplyQuote
(@derek-m)
Illustrious Member Moderator
14399 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4273
 

Posted by: @mjr

Posted by: @ajdunlop

Am I correct that the 'auto-adaption' feature applies to when the FTC6 main controller is set to room temperature mode or is it just if a wireless controller is used?

 

"Auto adaptation" is used when both the FTC6/5/maybe-others main controller is set to a room temperature and DIP switch SW1-8 in the big control box is set ON.

To clarify, Auto Adaptation can be used with just the main controller (provided that it is located within the room whose temperature is to be controlled), otherwise a remote sensor will be required as detailed below.

4.4.1 Connecting the room temp. thermistor (TH1) cable
TH1 is an optional part (PAC-SE41TS-E).
TH1 is required to use the auto adaptation function. However, when room temperature detection is conducted by the main remote controller or the wireless remote
controller (optional), this part is not required.
Connect the TH1 cable to the CN20 connector on FTC (Master).
When the TH1 cable is too long, bundle the excess cable outside the FTC (Master) unit.
For more details, refer to Section 4.3 in this manual or the installation manual that
comes with PAC-SE41TS-E.
When using TH1, place this sensor on appropriate location to detect room temperature.

DIP Switch SW1-8 will need to set to the ON position if a Wireless Remote Controller is installed.

To activate Advanced Auto Adaptation DIP Switch SW5-2 will need to be set to the ON position.

Posted by: @ajdunlop

I set our office's main controller to room temperature mode and it straight away went for a 50 degree flow temp overheating the place. I had set it up to use the WC curve with a max temperature of 38 degrees so it looks like it was ignoring that. I don't know if it would over time realise that was too aggressive and adapt down but I wasn't willing to subject my colleagues to that to find out.

That's basically my experience. I can tell you the next stage of what happens, too: it overshoots, then lowers the flow temperature right down, so the room temperature falls and then it goes for a high flow temperature again. I let it do that for a day once and it showed no sign of learning anything from its mistakes.

If I get the area up to temperature another way (using curve or flow modes), then auto-adapt seems able to hold a temperature OK and it can do one thing that I've never seen in the other two modes: pump water around the heating loop for fairly long periods (30+minutes) without running the heat pump itself until the flow temperature drops too far. This seems to be useful in winter where heat is lost faster and so the emitters can keep warming the rooms, but it seems a waste of energy in spring and autumn. The ecodan doesn't appear to count the (admittedly low) pump power as part of HeatingEnergyConsumed, which seems a bit naughty and gives flattering heating performance stats alongside more realistic overall ones.

The response that was experienced in the first instance sounds similar to switching an industrial control system from manual control to automatic control, without first balancing the control parameters. In fairness the information in the manual relating to Auto Adaptation is very sparse. I have e-mailed Mitsubishi to ask if there is any way to adjust the response of the controller to match the different response time to be experienced from home to home.

I will update if I get a reply.

 

Posted by: @ajdunlop

I wonder if it would be possible to limit it by changing the maximum flow temperature in the Operations Settings menu.

It looks like it should. You could also reduce the "thermo diff adjust upper limit" to stop it overshooting so far, but I wonder if that would be at the cost of more cycling in mild weather.

The FTC manual also says that there's a "Fast" mode which is even more aggressive and expensive. I shudder to think how that behaves!

 

 


   
SUNandAIR reacted
ReplyQuote
(@derek-m)
Illustrious Member Moderator
14399 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4273
 

@kev-m

Hi Kev,

Does the room thermistor give any details of its resistance, or any model number? It may be possible to modify the controller response by means of some additional resistors.


   
ReplyQuote



(@kev-m)
Famed Member Moderator
5562 kWhs
Joined: 3 years ago
Posts: 1299
 

Posted by: @derek-m

@kev-m

Hi Kev,

Does the room thermistor give any details of its resistance, or any model number? It may be possible to modify the controller response by means of some additional resistors.

Derek, this is what I installed.

https://library.mitsubishielectric.co.uk/pdf/book/pac-se41tse-installation-manual--wt02927x01-#page-1-2

 


   
ReplyQuote
(@derek-m)
Illustrious Member Moderator
14399 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4273
 

Posted by: @kev-m

Posted by: @derek-m

@kev-m

Hi Kev,

Does the room thermistor give any details of its resistance, or any model number? It may be possible to modify the controller response by means of some additional resistors.

Derek, this is what I installed.

https://library.mitsubishielectric.co.uk/pdf/book/pac-se41tse-installation-manual--wt02927x01-#page-1-2

 

Hi Kev,

I have looked at the Mitsubishi data, but it is not apparent what the nominal resistance value is for the actual thermistor.

 


   
ReplyQuote
(@kev-m)
Famed Member Moderator
5562 kWhs
Joined: 3 years ago
Posts: 1299
 

Posted by: @derek-m

Posted by: @kev-m

Posted by: @derek-m

@kev-m

Hi Kev,

Does the room thermistor give any details of its resistance, or any model number? It may be possible to modify the controller response by means of some additional resistors.

Derek, this is what I installed.

https://library.mitsubishielectric.co.uk/pdf/book/pac-se41tse-installation-manual--wt02927x01-#page-1-2

 

Hi Kev,

I have looked at the Mitsubishi data, but it is not apparent what the nominal resistance value is for the actual thermistor.

 

there are no markings on or inside the plastic box either.

 


   
ReplyQuote
(@derek-m)
Illustrious Member Moderator
14399 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4273
 

Hi Kev, mjr and other Ecodan owners,

I have been doing some investigation as to why the Ecodan Auto Adaptation would appear to not always perform as one would expect.

I sent the following e-mail to Mitsubishi Technical Help and received the reply show below.

Original message:-

Thank you for the reply.

Yes, several of the forum members did use the wireless controller, but found that when they initiated Auto Adaptation, the response from the controller was much too aggressive. Instead of gradually changing the temperature of the water produced by the heat pump from say 35C to 36C, it would bump the temperature up to approaching 50C, which is far from efficient. This would cause too high a temperature so the controller would then lower the water temperature to below 35C.

This caused the heat pump operation to cycle in an inefficient manner. This is not how I would expect Auto Adaptation to operate.

The description of Auto Adaptation in the manuals is rather vague, could you please clarify how it is designed to operate. When operating in Auto Adaptation mode, should the controller 'adapt' the system response, over time, to match the heat loss characteristics of the home in question?

My understanding of how Auto Adaptation should operate is that, the water temperature produced by the heat pump should follow the weather compensation curve, but if the indoor air temperature is below the desired temperature, the Auto Adaptation would add slightly to the weather compensation to gradual increase the water temperature, and hence increase the indoor air temperature. The reverse should occur if the indoor air temperature is too high.

Could you please clarify if my assessment of the control philosophy is correct?

Reply:-

Good Afternoon Derek,

Yes your description of the Auto adaption mode is quite accurate.

The controller will constantly monitor room temperature and vary the flow temperature depending on the outside ambient temperature and how far away the target temperature is from the actual room temperature.

It also has a self-learning function which will follow similar patterns it adapted to in the past. For example, if 3 days previously the outdoor ambient was 5 degrees and the room stat was set to 22 degrees and the room was at 20 degrees, it will look at the flow temperature it used that day to get the room up to 22 degrees and adapt the flow temperature accordingly. If the room temperature does not increase over a 1 hour period it will increase flow temperature by 1 degree every hour until it reaches room target temperature.

I hope this helps

For those of you 'brave' enough to give the Auto Adaptation mode a try, I would suggest that you change the 'Room temp, control - interval' from the default 10 minutes to the maximum 60 minutes, as shown on page B27 of the attached document. Don't forget that to use Auto Adaptation a wired temperature sensor or an RF controller will be required along with setting the appropriate DIP Switches.

If your system still fails to control the indoor temperature in a slow even manner then let me know as I have some further ideas that may be of use.


   
mjr reacted
ReplyQuote
(@kev-m)
Famed Member Moderator
5562 kWhs
Joined: 3 years ago
Posts: 1299
 

Posted by: @derek-m

Hi Kev, mjr and other Ecodan owners,

I have been doing some investigation as to why the Ecodan Auto Adaptation would appear to not always perform as one would expect.

I sent the following e-mail to Mitsubishi Technical Help and received the reply show below.

Original message:-

Thank you for the reply.

Yes, several of the forum members did use the wireless controller, but found that when they initiated Auto Adaptation, the response from the controller was much too aggressive. Instead of gradually changing the temperature of the water produced by the heat pump from say 35C to 36C, it would bump the temperature up to approaching 50C, which is far from efficient. This would cause too high a temperature so the controller would then lower the water temperature to below 35C.

This caused the heat pump operation to cycle in an inefficient manner. This is not how I would expect Auto Adaptation to operate.

The description of Auto Adaptation in the manuals is rather vague, could you please clarify how it is designed to operate. When operating in Auto Adaptation mode, should the controller 'adapt' the system response, over time, to match the heat loss characteristics of the home in question?

My understanding of how Auto Adaptation should operate is that, the water temperature produced by the heat pump should follow the weather compensation curve, but if the indoor air temperature is below the desired temperature, the Auto Adaptation would add slightly to the weather compensation to gradual increase the water temperature, and hence increase the indoor air temperature. The reverse should occur if the indoor air temperature is too high.

Could you please clarify if my assessment of the control philosophy is correct?

Reply:-

Good Afternoon Derek,

Yes your description of the Auto adaption mode is quite accurate.

The controller will constantly monitor room temperature and vary the flow temperature depending on the outside ambient temperature and how far away the target temperature is from the actual room temperature.

It also has a self-learning function which will follow similar patterns it adapted to in the past. For example, if 3 days previously the outdoor ambient was 5 degrees and the room stat was set to 22 degrees and the room was at 20 degrees, it will look at the flow temperature it used that day to get the room up to 22 degrees and adapt the flow temperature accordingly. If the room temperature does not increase over a 1 hour period it will increase flow temperature by 1 degree every hour until it reaches room target temperature.

I hope this helps

For those of you 'brave' enough to give the Auto Adaptation mode a try, I would suggest that you change the 'Room temp, control - interval' from the default 10 minutes to the maximum 60 minutes, as shown on page B27 of the attached document. Don't forget that to use Auto Adaptation a wired temperature sensor or an RF controller will be required along with setting the appropriate DIP Switches.

If your system still fails to control the indoor temperature in a slow even manner then let me know as I have some further ideas that may be of use.

Hi Derek, that's really useful.  I'll give this a try when Christmas is over and all our visitors have gone.  

Kev

 


   
ReplyQuote
(@derek-m)
Illustrious Member Moderator
14399 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4273
 

@kev-m

Hi Kev,

I have just finished calculating the resistance values that could be used to vary the response of the Thermistor TH1, which is used to measure the room temperature.

The thermistor has a negative temperature co-efficient, in that as the temperature increases its resistance reduces. From the data sheet it is quoted as  approximately 362k ohms at 10C and 150k ohms at 30C, though I am not certain if the change of resistance is linear.

Assuming a linear relationship over the 10C to 30C range, the thermistor's resistance at 20C would be approximately 256k ohms and at 21C approximately 245k ohms. A calculated change in resistance of 10.6k ohms per degree C.

Again making assumptions, since I don't have an Ecodan to cannot carry out detailed testing, I suspect that if auto adaptation is enabled with say a temperature setpoint of 21C, but an actual indoor temperature of 20C, the controller see's a large difference, resistance wise, and starts bumping up the LWT. Because the change in indoor temperature is quite slow, the controller continues raising the indoor temperature until it reaches the desired temperature setpoint. By now the heat pump has put too much heat energy into the property, so the actual room temperature exceeds the setpoint and the controller now starts to reduce the LWT. A typical control system response when the controller settings are too responsive.

What I suggest is installing a fixed value resistor in parallel with the actual thermistor, and then a second fixed value resistor in series with the thermistor and resistor combination. This would have the effect of reducing the overall resistance change experienced by the controller, such that it would be seeing a smaller temperature difference between the desired temperature and the actual temperature.

The value of the two resistors would be calculated so that they present the nominal resistance value to the controller, that it would normally  see at the desired temperature. Using this technique it should be possible to fine tune the response of the thermistor to match the characteristics of an individual's home.

I can provide further details to anyone who is interested.

This post was modified 2 years ago by Derek M

   
ReplyQuote



Page 2 / 8
Share:

Join Us!

Latest Posts

x  Powerful Protection for WordPress, from Shield Security
This Site Is Protected By
Shield Security