Calibration

 Hello everybody, I am trying to assembly the Ac Monitor, but I am having some problems. I think I have assembled it correctly but now I was trying to calibrate it but I am just receiving random numbers in my serial port.. I am using the basicSketchWCal to calibrate it.

Does anyone know what may be the problem. Thank you in advance. 

(I posted also in general discussion, sorry for double post) 

 

 

glyn.hudson's picture

Re: Calibration

 Try the new emonLib library: https://github.com/openenergymonitor/EmonLib. You will still need to calibrate for your component values. 

We have a page here that lists suggested calibration values for the emonTx AC-AC adapters: http://openenergymonitor.org/emon/buildingblocks/different-acac-power-adapters

We are currently in the process of improving the layout of the documentation on this site. If you can't find anyting please try the new 'building blocks section': http://openenergymonitor.org/emon/buildingblocks. This section will in due course replace input/output modules and builds. 

pd.gomes's picture

Re: Calibration

I am using the basicSketch calibration file to calibrate my values of phaseCal, Ical and Vcal. The problem is that I am trying to calibrate my phasecal but I can't and I don't know whats happening. I started by using the values that you refer like 2.3 but it seems like I am just receiving random numbers. 

The power factor is supposed to be 1 when there are any devices connect at the grid and then is supposed to go to a number around 0.85 or something. But the problem is that I cannot even measure 1 and when I connect a device and turn it on it seems to be not so effective in changing the values of the power factor. I really don't know what may be happening. 

Any clue? 

glyn.hudson's picture

Re: Calibration

Have you calibrated the Vcal and Ical? Try calibrating these first. You will need a plug in monitor on an extension cable to compare. The CT must be clipped round either the netral or live wire, not both. 

Calibrating phaseCal can be tricky, its often a bit of trail and error! A full resistive load such as an electric heater can be used to give a PF of 1. 

Calibration should be done with a load of a few Kw at least.

What is your setup? I take it your not using the emonTx? What component values are you using? 

pd.gomes's picture

Re: Calibration

 

My CT is only around live wire...I figured that the problem may be the connection of my power adapter to the breadboard because the wires don't fit in the holes..I will try somehow to make them fit and I will try again. 
 
I am using the assembly of mains Ac 3.0 non-invasive and my setup is:
 
// Voltage is reduced both by wall xfmr & voltage divider
#define AC_WALL_VOLTAGE        230 
#define AC_ADAPTER_VOLTAGE     9
// Ratio of the voltage divider in the circuit
#define AC_VOLTAGE_DIV_RATIO   11
// CT: Voltage depends on current, burden resistor, and turns
#define CT_BURDEN_RESISTOR    56
#define CT_TURNS              1500
 
I will try to fix my connection of the power transformer with the board, and if the problem remains I will tell you something.
 
Thank you for all! 

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