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Icon_missing_medium
May 26, 2015 12:40pm
3 posts

Hi,

Is there a way to include conditional logic in a calculated stream?

 

I'm running a open loop geothermal that shares the well pump with the house.  I currently have a calculated stream called 'eHeatCooling' that combines the cost of the Geothermal unit and the well pump...  I would like to be able to change the calculated stream to calculate only when the Geothermal is running...

 

IE -  eHeatCooling= Geothermal running? eGeothermal + eWellPump

 

since the WellPump is also being used for household usage, I'm getting 'eHeat' values even though I'm not heating or colling the house.

 

Thanks in advance

 

Luc.

 
Tony1_medium
May 26, 2015 1:46pm
169 posts

Currently how are you monitoring the two items, are you using CT's off the breaker panel for the well pump? How does the GEO trigger the well pump when it calls for the water flow?

 
Icon_missing_medium
May 26, 2015 1:57pm
3 posts

Hi,

Yes, both the Geothermal and the well pump are on seperatly monitored brakers..  The well pump is triggered when there is a demand for water. I realise that there will be a very slight discrepency if the GeoThermal is running and there is also a demand for water from another source ( ie, somewone is taking a shower) but that discrepency would be very small.

 

I can identify that the Geothermal is running if there is a draw on that breaker so I'd like to   do something like this:

 

If Geothermal > 0 then

   Calculated strem =  Geothermal + WellPump

else

   Calculated stream = 0

end

 

 

 

 

 
Tony1_medium
May 26, 2015 6:57pm
169 posts

As far as I know there is no way to use "if, else, then" logic but Sam can confirm this. The only way that I could see this being done is possibly using a relay that triggers a dry contact that would open and close a lead on the CT for the pump. So when the GEO signals the pump to start the relay would close to complete the connection for the CT. IF the CT on the Geo and pump are the same (40 amp CT) you probably could put them on the same channel. This way when the GEO starts the CT's would combine the numbers for a true picture.

Take a look at Functional Devices RIBU1C

I have two Geothermal units but mine are in a closed loop system so the pump(s) are used only for the GEO's so I just use a calculated stream to combine it for a total.

 
Icon_missing_medium
Jun 9, 2015 5:06pm
3 posts

Just a quick Update incase someone was trying to do something similar...

 

Since I couldn't figure out a suitable solution within the confines of the 'calculated stream' I ended up doing the calculation at capture, before the data is sent to the site.

 

In the Python script that I use to capture and then send the raw data to SEG, I added conditional logic that combines the values from the GeoThermal unit, the Electric emergency heat and the Water pump if and only if the GeoThermal is drawing power into a new stream.

 

I also added a calculated stream in SEG that then adds any energy used by the radiant floor heating that I have in the bathrooms...( This could also have been done in the script before sending the data)

 

So now I have a much more accurate representation of the energy used and subsequently, the cost of heating and cooling the house.

 Thanks to tnakelsk for your input.

 

Luc.

 

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