Current values are off

[defl]

First off, thanks for the esphome module for vue2, really nice and works like a charm.

I was trying to see if I could get the measured amperages out by using ct_clamps: input: current as configurable, but the numbers returned are not reasonable (123v, 2kw power, 897A?). I can see in the code there's a bit of magic (https://github.com/emporia-vue-local/esphome/blob/emporia-vue-2022.4.0/esphome/components/emporia_vue/emporia_vue.cpp#L118) to get corrected numbers for power. Any chance of a fix for current (in A)?

Thanks!

[flaviut]

Yup! The current numbers are way off. Not sure why, and I'm not sure if it's possible at all to fix them.

What you can do is create a set of computed fields that divide the power by that phase's voltage. Something similar to this perhaps?

  - platform: template
    name: "Circuit 1 Current"
    lambda: return id(cir1).state / id(phase_a_voltage).state;
    update_interval: 240ms
    id: cir1_current
    unit_of_measurement: "A"

[defl]

Thought of that as well, but felt a bit like a cop out :) Always, that's what it's going to be, thanks for the quick response.

[defl]

Allright, this bothered me enough to start to think about it and after a bit of playing I have a solution which gives reasonable numbers for me:

I took a few assumptions here, leaving it for you @flaviut to judge if they make sense:

1. I used the 5.5 correction factor I saw in the code for the A-C inputs.
2. Guessed that the default phase calibration of 0.022 wasn't random.
3. Measurement is actually in deci-amps

Then if you use real_current=measured_current/10/((2.2/used_phase_calibration)/100)/5.5 I get quite close for the sample values I took from my running system. One is within a percent and the other one is within 10% (but I don't fully trust my phase calibration numbers just yet, voltages seem bit too far).

Following are the numbers I used and a screenshot of the excel sheet for the calc:

Code for config:

sensor:
  ct_clamps:
      - input: "A"
        phase_id: phase_2
        current:
          name: "Phase 2 Current"
          id: phase_2_current
          filters: [*moving_avg, *pos]
        ...

Can somebody confirm if these numbers also work for them?

[Mrkricfalusi]

what I got on mine. anyway to make it report correctly in HA?

[defl]

Seems to be right. Just calculating the watts from P/V you get 7.35 but that's with a perfect power factor. Using the math above you get to 8.58A which would be a power factor of 0.85 which isn't unheard of if you have big inductive loads (motors). (Or so I believe, I'm not an expert in this.)

[ozzy]

Hi @defl ,

Did you come to any conclusion ?
Should such a fix be the default config ?

Best regards,
Oz

[defl]

Ah never looked at it further. I believe @priitka 's solution as well, the less factors required to get close to the right number the better.

[priitka]

For me adding
filters: [*moving_avg, *pos, multiply: 0.00454545 ]
produced correct amps (verified by ampmeter), when using 50A clamps. 0.00454545 = 0.1 / 22.
I didn't try it, but for 200A clamps 0.0181818 = 0.1 / 5.5 should be correct.
@defl suggested to adjust multiplier with voltage correction, but this doesn't seem right

[ozzy]

Hi @priitka ,

I am new to esphome and vue2 and I am struggling to configure my system.
My site is single phase with single phase PV and seperate battery invertor.

Would you be kind enough to post your config in the hope that I can figure out what I am doing wrong ?

Best regards,
Oz

[ludoviclehmann]

Has this been fixed recently?
I just tried following code without any multiplier:

 ct_clamps:
  - phase_id: phase_a
    input: "A"  # Verify the CT going to this device input also matches the phase/leg
    power:
      name: "Phase A Power"
      id: phase_a_power
      device_class: power
      filters: [*moving_avg]
    current:
      name: "Phase A Current"
      id: phase_a_current
      device_class: current
      filters: [*moving_avg, *pos]
  - phase_id: phase_b
    input: "B"  # Verify the CT going to this device input also matches the phase/leg
    power:
      name: "Phase B Power"
      id: phase_b_power
      device_class: power
      filters: [*moving_avg]
    current:
      name: "Phase B Current"
      id: phase_b_current
      device_class: current
      filters: [*moving_avg, *pos]
  - phase_id: phase_c
    input: "C"  # Verify the CT going to this device input also matches the phase/leg
    power:
      name: "Phase C Power"
      id: phase_c_power
      device_class: power
      filters: [*moving_avg]
    current:
      name: "Phase C Current"
      id: phase_c_current
      device_class: current
      filters: [*moving_avg, *pos] 

Here are the results that I get:

• Phase A: voltage: 226.2 V, power: 1071.2 W, current: 5.49 A
• Phase B: voltage: 239.9 V, power: 431.0 W, current: 2.65 A
• Phase C: voltage: 228.0 V, power: 769.4 W, current: 3.89 A

The current readings seem to make sense.

Edit: just saw this PR which has been merged: #90

According to the readings, it is the apparent current.