I have done another log when I was charging my smartphone. The SDM120 kWh meter can read:
print ("Voltage in Volts: ", V)
print ("Current in Amps:", I)
print ("Active Power in Watts:", P)
print ("Apparent power in VA:", VA)
#24 --> Reactive power in VAr
print ("Power factor:", PF)
print ("Frequency in Hz:", FR)
print ("Import active energy in kWh:", EI)
print ("Export active energy in kWh:", EE)
print ("Export reactive energy in kWh:", RI)
The export from emoncms shows:
"Seconds since start", "I", "V", "P", "VA", "PF", "FR", "RI"
0, 0.000, 238.6, 0.000, 0.000, 1.000, 49.950, 2.9
10, 0.034, 238.8, 0.000, 0.000, 1.000, 50.000, 2.9
20, 0.034, 238.7, 0.000, 0.000, 1.000, 50.000, 2.9
30, 0.034, 238.6, 0.000, 0.000, 1.000, 50.000, 2.9
40, 0.034, 238.5, 0.000, 0.000, 1.000, 50.000, 2.9
50, 0.034, 238.2, 0.000, 0.000, 1.000, 50.000, 2.9
60, 0.034, 238.4, 0.000, 0.000, 1.000, 50.000, 2.9
70, 0.034, 237.6, 0.000, 0.000, 1.000, 50.000, 2.9
80, 0.034, 238.1, 0.000, 0.000, 1.000, 50.000, 2.9
90, 0.034, 236.2, 0.000, 0.000, 1.000, 50.000, 2.9
I don’t understand eg. at 10 seconds I have 0.034 A and 238.8 V. I would expect the voltampere to be VA = 0.034 A * 238.8 V = 8.1124 VA, but it shows 0.000? Also the power should be a lot higher, I think.
If I do a logging with my desk lamp connected (I think it has LED), I have P and VA, but still VA = V * A gives another calculation (13,07 VA) compared to the logging (5,9 VA).
"Seconds since start", "I", "V", "P", "VA", "PF", "FR", "RI"
0, 0.000, 237.6, 0.000, 0.000, 1.000, 50.000, 2.9
10, 0.055, 237.7, 5.800, 5.900, 1.000, 49.950, 2.9
20, 0.055, 237.6, 5.700, 5.700, 1.000, 50.000, 2.9
30, 0.054, 237.7, 5.800, 5.800, 1.000, 50.000, 2.9