Weak Borehole Control Using A Sonoff R2 and Home Assistant!

I had a borehole drilled almost 4 years back, but it was never a very strong hole. I could pump up to 1400 L and then I had to let it rest for at least 3 hours for the hole to fill up again before i could pump again. As time went by we realised that the time I could pump depended on the season and the ground water level.
In the summer I could pump for 35-40min but in the winter only for 25min max. I ended up using multiple automation’s for stopping and starting the borehole. I also have an level switch in series with the output of the Sonoff that can prevent the pump from starting when the tank is full. (Still need to wire the level switch back directly to the “Home Assistant” )

We also saw that with almost emptying the borehole with ever pump, that we had sand reaching the house filters ext, so we installed filters between the borehole and the storage tank. With time they block up and restrict the flow resulting in the tank not filling up in the allowed pumping time. This restriction can also cause a condition similar to a dry run condition and this is dangerous for the pump, so i had to rethink this control philosophy completely. I was also sitting with a condition where the sonoff would be on for 20 min every 3? hours without the pump running because the tank was full.

I then did the following:

I measured the current with an open pipe and saw that the motor draws 3.24Amps when moving the max water it can for the specific head in my installation.
I then started throttling the outlet pipe and recorded the current till the outlet was completely closed and recorded 2.56amps when the motor is moving no water at all.

I then used 3 automation’s in total to control the pump.
1: To start the pump, Three hours after it stopped.
2: To stop the pump as the hole starts emptying. (<2.8 amps)
3: To stop the Automation if the Start automation triggered a start while the tank is full. If this automation dont see current within 10 seconds after switching the sonoff on, it will switch the sonoff off again. (after 3 hours it will restart process and if there is space in the tank , the pump will continue running)

Benefit of new control:
1: Pump time will automatically follow seasonal changes in under ground water level.
2: Offer protection against Dry run conditions
3: Protect motor again overheating in the case of a blocked filter.
4: Prevent the sonoff from being on while the tank is full

- id: '1640943414758'
  alias: Borehole Level Stop
  description: ''
  trigger:
  - platform: numeric_state
    entity_id: sensor.borehole_current
    below: '2.8'
  condition:
  - condition: state
    entity_id: switch.borehole_sonoff
    state: 'on'
  action:
  - service: switch.turn_off
    target:
      entity_id: switch.borehole_sonoff
  mode: single
- id: '1640950235654'
  alias: Borehole Start
  description: ''
  trigger:
  - platform: state
    entity_id: switch.borehole_sonoff
    from: 'on'
    to: 'off'
    for:
      hours: 3
      minutes: 0
      seconds: 0
      milliseconds: 0
  condition: []
  action:
  - service: switch.turn_on
    target:
      entity_id: switch.borehole_sonoff
  mode: single
- id: '1640951248327'
  alias: Borehole Full Start Reset
  description: ''
  trigger:
  - platform: state
    entity_id: switch.borehole_sonoff
    from: 'off'
    to: 'on'
    for:
      hours: 0
      minutes: 0
      seconds: 10
      milliseconds: 0
  condition:
  - condition: not
    conditions:
    - condition: numeric_state
      entity_id: sensor.borehole_current
      above: '1'
  action:
  - service: switch.turn_off
    target:
      entity_id: switch.borehole_sonoff
  mode: single

3 Likes

Very cool!

Would be worthwhile writing this as some rules directly in Tasmota - in case connection with HA drops or HA goes down. That way the pump protection is built into the device controlling it!

2 Likes

Jaco, have you investigated adding run time based on PV production to this?

I did that in the beginning, then I realized with our normal daily water usage and no obstructions the borehole runs for less than 1 hour on average per day. I use to allow it to run for 3 times 20 min cycles per day during sunlight hours. With an average consumption of less than 750wh per day, I don’t really worry if it comes from the panels or the batteries.

1 Like

Agree, I will look into that before I hit the road again. Thanks, to be honest I did consider that, but never got around to it…