I have https://docs.openenergymonitor.org/emonpi/technical.html that is monitoring our incoming mains supply. It has
That also feeds into Home Assistant. Throughout the house are UP111 smart plugs, that also feed into Home Assistant. This allows me to draw graphs like this
Before installing the current clamp on the meter tails, I calibrated it using a Fluke 179 to measure current and a Brymen meter for the voltage. I used a kettle as the load for doing this.
I used the same kit to calibrate the smart plugs, and they all read close to each other still.
The problem I'm seeing is that sometimes there is more monitored load than current transfer thinks is coming in;
I'm using the incoming data from that to total up how much power is consumed in the house per day and the reading from the current clamp consistently reads lower than the data I get from reading via the pulse counter on the meter. This difference is typically 4-5% per day.
To try and get some sense, I bought a clamp meter to run next to it and verify. The two sensors did not agree.
Now I'm not sure what to trust, so wired my Fluke 179 inline with the kettle and put the clamp meter on the live wire - to see what each meter said.
Well that's not right, I'm more inclined to trust the in-line meter. I then moved the postition of the wire within the clamp and...
That's not helpful. It's quite a difference in just moving the conductor from the end of the jaw to near the meter body.
So now I don't know what to trust.
My Fluke clamp meter is old, and also reads up to 200A. (400A in the other setting). I don't need that scale, so started looking at 80A-100A meters instead. Prices vary massively and I don't want to buy something that's not going to be accurate, else what's the point.
Or am I chasing differences in how the two measuring devices work. The smart plugs can show me power factor and active / reactive power. What is the current transformer doing.
- Current Transformer rated to 100A
- AC voltage sesnsor
- Optical Pulse counter that is attached to the meter, counting kwh
That also feeds into Home Assistant. Throughout the house are UP111 smart plugs, that also feed into Home Assistant. This allows me to draw graphs like this
Before installing the current clamp on the meter tails, I calibrated it using a Fluke 179 to measure current and a Brymen meter for the voltage. I used a kettle as the load for doing this.
I used the same kit to calibrate the smart plugs, and they all read close to each other still.
The problem I'm seeing is that sometimes there is more monitored load than current transfer thinks is coming in;
I'm using the incoming data from that to total up how much power is consumed in the house per day and the reading from the current clamp consistently reads lower than the data I get from reading via the pulse counter on the meter. This difference is typically 4-5% per day.
To try and get some sense, I bought a clamp meter to run next to it and verify. The two sensors did not agree.
Now I'm not sure what to trust, so wired my Fluke 179 inline with the kettle and put the clamp meter on the live wire - to see what each meter said.
Well that's not right, I'm more inclined to trust the in-line meter. I then moved the postition of the wire within the clamp and...
That's not helpful. It's quite a difference in just moving the conductor from the end of the jaw to near the meter body.
So now I don't know what to trust.
My Fluke clamp meter is old, and also reads up to 200A. (400A in the other setting). I don't need that scale, so started looking at 80A-100A meters instead. Prices vary massively and I don't want to buy something that's not going to be accurate, else what's the point.
Or am I chasing differences in how the two measuring devices work. The smart plugs can show me power factor and active / reactive power. What is the current transformer doing.
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