I installed a PJ1203 clamp energy meter a while ago. We’re getting a 49 deg c day tomorrow, and I’ve been looking at current to see if my air conditioners are anywhere near capacity. I have verified the amps accuracy with a clamp multimeter, and voltage is good as I have a few other smart things measuring the same. What gets me is the power (watts) on the dashboard. How can it come up with a number like that, when the maths (volts x amps = watts) does not add up? Am I reading it wrong?
Can you get the power factor displayed? If it’s around 0.5, your apparent power would be 2kW, but real power 1kW.
It would not show any entities in ZHA, so I went with Z2M and they are the only entities revealed. Tuya PJ-1203-W control via MQTT | Zigbee2MQTT mentions power factor, but I can’t see it in yaml.
In any case real power is not voltage times current in case of air conditioner. Power factor of 0.5 is possible with A.C.
I’m after real power consumed - trying to do math for solar & batteries. I change the “power calibration” ratio in Z2M for the clamp, but no change in W is displayed. Why can’t I have W = V x I ?
Because only in case of purely resistive load it’s V x I.
And A.C. is not resistive load.