02-16-2024, 10:51 PM
[quote pid="11787" dateline="1708112777"]
Was also my plan: will use an accurate socket power meter and read the power factor and then use this as a static value to calculate the power. Could work for always-on devices or devices with stable power factor.
But there are also quite a few devices for which the power factor varies greatly, especially when they are in standby or some low/medium/high mode (like my ventilation unit - or my oven in standby vs in use because of the electronics/digital clock). My led drivers are also a pain to measure.
Maybe I can take multiple measurements depending on the state and then apply some if-then-else logic for the calculation in esphome or home assistant.
I should give up on trying to be watt-accurate, after all I would be happy to be able to get a good overview of the distribution of my energy usage throughout the house.
I think that should work. 0.1.
Btw, a tip to get more calibration points: you can just wrap the wire around the CT multiple times. e.g. if you have a stable 1A load and you wrap it around 4 times you can use that as a reference point for a 4A load.
I just calibrated them outside my cabinet before installing them on the lines I needed. But during testing I tried to move and wiggle them around but that didn't seem to affect the readings.
Didn't see a difference between having 1 or all 16 lined up next to each other, so I think that is quite ok.
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Quote:I hope I get the power factor rather stable for the loads I want to measure, but we'll see.
Was also my plan: will use an accurate socket power meter and read the power factor and then use this as a static value to calculate the power. Could work for always-on devices or devices with stable power factor.
But there are also quite a few devices for which the power factor varies greatly, especially when they are in standby or some low/medium/high mode (like my ventilation unit - or my oven in standby vs in use because of the electronics/digital clock). My led drivers are also a pain to measure.
Maybe I can take multiple measurements depending on the state and then apply some if-then-else logic for the calculation in esphome or home assistant.
I should give up on trying to be watt-accurate, after all I would be happy to be able to get a good overview of the distribution of my energy usage throughout the house.
Quote:That's what I was afraid to see. Good to know I need to find smaller resistive loads as well. My current lowest is around 0.65A but some loads I want to measure get down to 0.1A.
I think that should work. 0.1.
Btw, a tip to get more calibration points: you can just wrap the wire around the CT multiple times. e.g. if you have a stable 1A load and you wrap it around 4 times you can use that as a reference point for a 4A load.
Quote:Wouldn't it be better to measure on actual wires in the walls? I believe the readings may be influenced by plenty of wires around in my fuse box.
I just calibrated them outside my cabinet before installing them on the lines I needed. But during testing I tried to move and wiggle them around but that didn't seem to affect the readings.
Didn't see a difference between having 1 or all 16 lined up next to each other, so I think that is quite ok.
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