Custom power meter

RJ_Make

@maglo18 Is that 3 transformers in that box?

maglo18

@ServiceXp In the box are 3 transformer, one for each phase to measure the voltage

gigi

@maglo18 How to transmit data to emoncms?

maglo18

I use Pidome server and by automation rule send values to emoncms..

tbully

Hello,

I've been looking in to this for quite some time. Here in the US, our residential wiring is usually 220V "split-phase" where we have a neutral/ground connection that allows us to get 120V from either "leg" (not to be confused with phase) to "ground". If you go "leg to leg", you'll get the full 220V of the phase.

I've been searching quite a bit and am a little confused so I was hoping that you could expand on your solution a bit. (schematics, part numbers, full sketch) Your efforts look great. I'm wondering how you've integrated in to MySensors (and your controller, Vera?)

In my case, I think that I will need to do the following:

Have two CT's - one for each leg
Have two transformers to measure each leg to neutral
Somehow convert the voltage-measurement transformers in to something Arduino can read (0-5V)
Convert the current induced by the CTs to a voltage that the Arduino can read
Do the "V*I" math to calculate power, etc.

Most US based solutions call for only one transformer/leg-measurement. However, I have seen an imbalance in my utility power. I'm not sure if this is due to underground resistance, faulty utility transformers, etc. But my point is, I think it'd be safer to measure both, do my calculations separately, and then add them accordingly (in software) to get total power consumption.

Can you expand a bit on my thoughts? Has anyone in the US been successful in my above approach?

epierre

@maglo18 why do you need a transformer ? my owl ones work on battery, couldn't that simplpify the sketch ?

maglo18

I use transformer to measure voltage on each from three phases

chatainsim

@maglo18 how many is your burden resistor ?
If found a blog where he talk about of turn in the sensor, do you know how many is it ?
http://www.homautomation.org/2013/09/17/current-monitoring-with-non-invasive-sensor-and-arduino/

Didi

@maglo18

please explain how to use one transformer on 3 phases to measure voltage on each

epierre

@maglo18 said:

I use transformer to measure voltage on each from three phases

I have at home some OWL CM180i that work on batteries... how can it be applied to the example here ?

maglo18

I use 3 x transformers One for each phase

Didi

@maglo18 said:

I use 3 x transformers One for each phase

Sorry for me it sounds like you use 1 transformer that was confusing me ;-)

ewgor

Have anyone integrated this with Openhab? can we find somwhere some Openhab items, rules for this sketch that @maglo18 posted here http://forum.mysensors.org/topic/1464/sct-013-030-current-monitor-sensor?
Thanks for any help!

Gambituk

Hi @maglo18 i have been using a current only version of emon for quite some time, i am interested in adding the ac-ac transformer to calculate the apparent power more accurately. Do you have a project page for your build with diagrams and specs? What type of transformers are you using (i can just about read it from picture) and how happy are you with the performance?

Thanks Gambituk

ewgor

Hi All,

Did anyone worked with this sensor SCT-013-000 and Openhab? I would like to ask how can I integrate this with Openhab so to be able to display the apparent power consumption in watts, to display the Kwh starting a certain date lets say starting on 12th this month or from today as for example and to display to total Kwh.
@maglo18 where are you from?

Any help or suggestion will be kindly appreciated.

Thanks All!

maglo18

@GambitukI am very happy with performance. I'm logs power every 10s and voltage every 60s. It is sufficient. I built like on this site http://openenergymonitor.org/emon/buildingblocks/measuring-voltage-with-an-acac-power-adapter
You can use transformer what you like but you must add voltage divider to have voltage max 2,5V on input in arduino if you use arduino 5V

PS Poland/Warsaw

ewgor

@maglo18 I saw some words in your pictures that looks familiar like faza or analizator :)
Can you share your latest Arduino sketch or if you have a complete tutorial about this project would be helpful.
Thanks!

jeti

@maglo18: is the sketch in the first post your latest version? I would also like to do a very similar build and would like to get the best base :)

thanks!

maglo18

This is my last and my final sketch

#include <SPI.h>
#include <MySensor.h>  
#include "EmonLib.h"             // Include Emon Library
EnergyMonitor emon1;             // Create an instance
EnergyMonitor emon2;             // Create an instance
EnergyMonitor emon3;             // Create an instance
#define CHILD_ID 0  
#define CHILD_ID2 1  
#define CHILD_ID3 2  
MySensor gw;
unsigned long lastSend;
unsigned long SEND_FREQUENCY = 10000; // Minimum time between send (in milliseconds). We don't wnat to spam the gateway.
unsigned long lastSend2;
unsigned long SEND_FREQUENCY2 = 300000; // Minimum time between send (in milliseconds). We don't wnat to spam the gateway.

MyMessage realPowerMsg(CHILD_ID,V_VAR1);
MyMessage apparentPowerMsg(CHILD_ID,V_VAR2);
MyMessage powerFActorMsg(CHILD_ID,V_VAR3);
MyMessage supplyVoltageMsg(CHILD_ID,V_VAR4);
MyMessage IrmsMsg(CHILD_ID,V_VAR5);

MyMessage realPowerMsg2(CHILD_ID2,V_VAR1);
MyMessage apparentPowerMsg2(CHILD_ID2,V_VAR2);
MyMessage powerFActorMsg2(CHILD_ID2,V_VAR3);
MyMessage supplyVoltageMsg2(CHILD_ID2,V_VAR4);
MyMessage IrmsMsg2(CHILD_ID2,V_VAR5);

MyMessage realPowerMsg3(CHILD_ID3,V_VAR1);
MyMessage apparentPowerMsg3(CHILD_ID3,V_VAR2);
MyMessage powerFActorMsg3(CHILD_ID3,V_VAR3);
MyMessage supplyVoltageMsg3(CHILD_ID3,V_VAR4);
MyMessage IrmsMsg3(CHILD_ID3,V_VAR5);

void setup()
{  
  gw.begin(NULL, 4, false, 0);
  Serial.begin(115200); // opens serial port, sets data rate to 9600 bps
  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("Energy Meter x 3v2", "1.2");
  // Register this device as power sensor
  gw.present(CHILD_ID, S_POWER);
  gw.present(CHILD_ID2, S_POWER);
  gw.present(CHILD_ID3, S_POWER);

  emon1.voltage(A3, 116.26, 1.7);  // Voltage: input pin, calibration, phase_shift
  emon1.current(A0, 29.0);       // Current: input pin, calibration.
  emon2.voltage(A4, 116.66, 1.7);  // Voltage: input pin, calibration, phase_shift
  emon2.current(A1, 29.0);       // Current: input pin, calibration.
  emon3.voltage(A5, 115.91, 1.7);  // Voltage: input pin, calibration, phase_shift
  emon3.current(A2, 29.0);       // Current: input pin, calibration.
}

void loop()
{
  gw.process();
  unsigned long now = millis();
  emon1.calcVI(20,2000);         // Calculate all. No.of half wavelengths (crossings), time-out
  //emon1.serialprint();           // Print out all variables (realpower, apparent power, Vrms, Irms, power factor)
  emon2.calcVI(20,2000);         // Calculate all. No.of half wavelengths (crossings), time-out
  //emon2.serialprint();           // Print out all variables (realpower, apparent power, Vrms, Irms, power factor)
  emon3.calcVI(20,2000);         // Calculate all. No.of half wavelengths (crossings), time-out
  //emon3.serialprint();           // Print out all variables (realpower, apparent power, Vrms, Irms, power factor)

  bool sendTime = now - lastSend > SEND_FREQUENCY;
  if (sendTime) { 

    float realPower       = emon1.realPower;        //extract Real Power into variable
    float realPower2       = emon2.realPower;        //extract Real Power into variable
    float realPower3       = emon3.realPower;        //extract Real Power into variable

    if(realPower > 0 && realPower < 10000){
    gw.send(realPowerMsg.set(realPower,1));
    }
    if(realPower2 > 0 && realPower2 < 10000){
    gw.send(realPowerMsg2.set(realPower2,1));
    }
    if(realPower3 > 0 && realPower3 < 10000){
    gw.send(realPowerMsg3.set(realPower3,1));
    }
    lastSend = now;
  }

  bool sendTime2 = now - lastSend2 > SEND_FREQUENCY2;
  if(sendTime2){

    float apparentPower   = emon1.apparentPower;    //extract Apparent Power into variable
    float powerFactor     = emon1.powerFactor;      //extract Power Factor into Variable
    float supplyVoltage   = emon1.Vrms;             //extract Vrms into Variable
    float Irms            = emon1.Irms;             //extract Irms into Variable
    
    float apparentPower2   = emon2.apparentPower;    //extract Apparent Power into variable
    float powerFactor2     = emon2.powerFactor;      //extract Power Factor into Variable
    float supplyVoltage2   = emon2.Vrms;             //extract Vrms into Variable
    float Irms2            = emon2.Irms;             //extract Irms into Variable
    
    float apparentPower3   = emon3.apparentPower;    //extract Apparent Power into variable
    float powerFactor3     = emon3.powerFactor;      //extract Power Factor into Variable
    float supplyVoltage3   = emon3.Vrms;             //extract Vrms into Variable
    float Irms3            = emon3.Irms;             //extract Irms into Variable


    if(apparentPower > 0 && apparentPower < 10000){
    gw.send(apparentPowerMsg.set(apparentPower,1));
    }
    if(powerFactor > 0 && powerFactor < 10000){
    gw.send(powerFActorMsg.set(powerFactor,1));
    }
    if(supplyVoltage > 0 && supplyVoltage < 1000){
    gw.send(supplyVoltageMsg.set(supplyVoltage,1));
    }
    if(Irms > 0 && Irms < 1000){   
    gw.send(IrmsMsg.set(Irms,1));
    }

    if(apparentPower2 > 0 && apparentPower2 < 10000){
    gw.send(apparentPowerMsg2.set(apparentPower2,1));
    }
    if(powerFactor2 > 0 && powerFactor2 < 10000){
    gw.send(powerFActorMsg2.set(powerFactor2,1));
    }
    if(supplyVoltage2 > 0 && supplyVoltage2 < 1000){
    gw.send(supplyVoltageMsg2.set(supplyVoltage2,1));
    }
    if(Irms2 > 0 && Irms2 < 1000){   
    gw.send(IrmsMsg2.set(Irms2,1));
    }

    if(apparentPower3 > 0 && apparentPower3 < 10000){
    gw.send(apparentPowerMsg3.set(apparentPower3,1));
    }
    if(powerFactor3 > 0 && powerFactor3 < 10000){
    gw.send(powerFActorMsg3.set(powerFactor3,1));
    }
    if(supplyVoltage3 > 0 && supplyVoltage3 < 1000){
    gw.send(supplyVoltageMsg3.set(supplyVoltage3,1));
    }
    if(Irms3 > 0 && Irms3 < 1000){   
    gw.send(IrmsMsg3.set(Irms3,1));
    }
    lastSend2 = now;
  }
}

ewgor

Thank you for sharing this code.
I modified your code only for a CT sensor which is connected to A0. The CT is connected to a 40 Watts lamp and this is what i get on Arduino serial monitor:

sensor started, id 4
send: 4-4-0-0 s=255,c=0,t=17,pt=0,l=5,st=ok:1.4.1
send: 4-4-0-0 s=255,c=3,t=6,pt=1,l=1,st=ok:0
send: 4-4-0-0 s=255,c=3,t=11,pt=0,l=18,st=ok:Energy Meter x 3v2
send: 4-4-0-0 s=255,c=3,t=12,pt=0,l=3,st=ok:1.2
send: 4-4-0-0 s=0,c=0,t=13,pt=0,l=0,st=ok:
send: 4-4-0-0 s=0,c=1,t=24,pt=7,l=5,st=ok:0.1

what is the last value (0.1)? Amps? if i turn off the lamp the i get 0.0!
In your sketch i see you calculate the real power, power factor, Vrms (volts?) and Irms (Amps?)

    float apparentPower   = emon1.apparentPower;    //extract Apparent Power into variable
    float powerFactor     = emon1.powerFactor;      //extract Power Factor into Variable
    float supplyVoltage   = emon1.Vrms;             //extract Vrms into Variable
    float Irms            = emon1.Irms;             //extract Irms into Variable

why is displaying in the serial monitor only one value which i assume is Irms?

I would like to calculate only the power and to export this to openhab but.....i dont know how :(

Custom power meter

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