CT clamp sensor not functioning

Hi,

My CT clamp sensor does not seem to register power consumption and I am out of ideas for debugging this issue.

The setup

  • I am using the following hardware:
    • SCT013-030 with built in burden resistor. I also have SCT013-000 available for testing if needed.
    • ESP-32
    • ADS1115
  • The wiring is done following this diagram
  • The clamp is connected around single wire
  • I have tried simple voltage divider setup with similar results

The esphome config is as follows:

i2c:
  sda: 21
  scl: 22
  scan: true

ads1115:
  - address: 0x48
    continuous_mode: true

sensor:
  - platform: ads1115
    id: "a0_a1_voltage_raw"
    multiplexer: 'A0_A1'
    gain: 6.144
    name: "raw"
    update_interval: 1s
    internal: true
    
  - platform: ct_clamp
    sensor: "a0_a1_voltage_raw"
    name: "Channel A Current"
    id: channel_a_current
    sample_duration: 200ms
    update_interval: 2s

The problem
I seem to get a very small variation in current measurement although I am connecting a 2.7KW iron that should result in close to 12 Amps.
The logs seem to constantly read the same:

[18:17:56][D][ads1115:164]: 'raw': Got Voltage=0.985313V
[18:17:56][D][sensor:127]: 'raw': Sending state 0.98531 V with 3 decimals of accuracy
[18:17:56][D][ct_clamp:038]: 'Channel A Current' - Raw AC Value: 0.960A after 152 different samples (760 SPS)
[18:17:56][D][sensor:127]: 'Channel A Current': Sending state 0.95995 A with 2 decimals of accuracy
[18:17:57][D][ads1115:164]: 'raw': Got Voltage=1.054500V
[18:17:57][D][sensor:127]: 'raw': Sending state 1.05450 V with 3 decimals of accuracy
[18:17:58][D][ads1115:164]: 'raw': Got Voltage=1.056563V
[18:17:58][D][sensor:127]: 'raw': Sending state 1.05656 V with 3 decimals of accuracy
[18:17:58][D][ct_clamp:038]: 'Channel A Current' - Raw AC Value: 0.933A after 152 different samples (760 SPS)

More info about configuration and full logs can be read from here: https://pastebin.com/raw/08PPMFrF
During this testing session of approximately 2 minutes the iron was on 10-15 seconds somewhere in the middle.

Any luck getting this to work?