I am using an emonPi to measure power consumption at two levels:
- Aggregated power consumption of the whole house
- Power consumption at the circuit level, in concrete the kitchen
The aggregated measures are consistent and make sense with the total billing at home. But I am having some issues with the kitchen level, as I have negative readings in the kitchen. I don’t understand this behaviour. Each day I measure around 80.000 measures, and I have around 90 negative measures. It is a small number in proportion, but it should be non-negative values at all. The aggregated measure is consistent, and I do not have even one negative reading.
I guess it could be issues of the calibration of the sensor, but again, why negative? I don’t know how the sensor works, but maybe someone could give me more insight into this.
Can anyone help me to sort out this problem?