Archived Forum

A few questions:

Are you using emontx_temperature_power.ino because it has code for the 4 temperature sensors?

Am I right in thinking that you do not want any electrical measurements?

How do you know the flow rate - is it always exactly 6 m³/h or do you need to measure it by counting pulses from your meter?

If all you need is the maths then:

Inside "typedef struct {..." change "int realPower" to read:
    double HeatPower;
and delete "int apparentPower;"

Add 2 new lines below "const int LEDpin = 9;"
    const double heatCap = 4195.5;
    const double flowrate = 6.0;

Remove the comment mark from "// emontx.T2 = ...." so that the line reads:
    emontx.T2 = sensors.getTempC(address_T2) * 100;

Remove:
    ct1.calcVI(20,2000); // Calculate all. No.of crossings, time-out
    emontx.realPower = ct1.realPower;
    emontx.apparentPower = ct1.apparentPower;

add a new line in the same place:
    emontx.HeatPower = (emontx.T2 - emontx.T1) / 100.0 * flowrate * heatCap;

Depending on how you receive and display the data, you must change something, either in emonHub or emonCMS (or both) to accept a "double" as the first value sent by your sketch. You will also need to decide the units you want to display in.

I sure like to  use  the electrical measurement for the consumption.

I need this to compare the electric consumption whit the heat production. The heat production can be measured to measure the energy that is become out the water.

Therefore I need to measure the  water temperature from the water incoming and outgoing of the heat pump.

Because I now the constant flow of the water in the primary part of the heat pump the heat production can be calculated. 

To compare these two energy values I get the COP of the heat pump

Many thanks for your help.

I added the lines you mentioned and it is working now.

I now know some commands  to programming further.

I still have a question, Is it possible to added lines to view the measured currents? 

The reason is that I have a big different between the realPower and  apparentPower

Regards, Frans

View where? If you have a programmer connected to the FTDI port on your emonTx, you can add "print" statements:

Serial.print("Real Power = ");
Serial.print(ct1.realPower);
Serial.print(", Apparent Power = ");
Serial.println(ct1.apparentPower);

There might be two reasons for the difference between real and apparent power. First, you may have a load that is part-reactive, or it appears to be part-reactive. Any load with electronic controls can behave in this way. Second, unless you have calibrated your emonTx, the phase shifts introduced by your ac adapter and current transformer might not be the standard values, and the time delay between reading voltage and current might not be the standard that we allow for. These together make a purely resistive load look like a reactive load, and must be corrected by changing PhaseCal (normally set to 1.7 by default). You can read how to calibrate your emonTx in Building Blocks > Calibration.

This is what I got;

emontx.realPower -32      tx.apparentPower 375.71   tx.powerFactor -0.09    Vrms 228.12

RealPower ct1 = -32.38, ApparentPower ct1 = 375.71

RealPower ct2 = -32.38 ApparentPower ct2 = 375.71

RealPower ct3 = -32.38 ApparentPower ct3 = 375.71

emontx.realPower 3225    tx.apparentPower 12228.14   tx.powerFactor 0.26   Vrms 225.53

RealPower ct1 = 3225.09, ApparentPower ct1 = 12228.14

RealPower ct2 = 3225.09 ApparentPower ct2 = 12228.14

RealPower ct3 = 3225.09 ApparentPower ct3 = 12228.14

the first is when my heat pump is out, the second when it is running.

Hereunder the result whit the 3 faze voltage sketch

Voltage: 223.04

Current 1: 4.89 Power 1: 842.33 VA 1: 1090.99 PF 1: 0.77

Current 2: 4.80 Power 2: 833.65 VA 2: 1070.29 PF 2: 0.78

Current 3: 4.91 Power 3: 813.86 VA 3: 1094.53 PF 3: 0.74

I did calibrade

I now get the idea that the sketch isn’t for 3 faze power

Nothing here is designed for a 3-phase system, as that is very rare for a UK domestic installation. However, there are two ways to use the emonTx on a 3-phase supply. The obvious way is to use three separate units, one emonTx on each phase. This is likely to give the most accurate results. The second is to use a sketch with "3phase" in the name. The emonTx does not have three voltage inputs, therefore those sketches synthesize in software the voltage waves for the second and third phases, giving an approximation, but hopefully a good approximation, of the missing voltages and that allows the power on each phase to be calculated. If the voltages across the three phases are accurately balanced, the approximation will be good and you should see accurate results.

You did not say you had a 3-phase installation, and you did not say which sketch you were using, so nobody could guess that you had the wrong one.