Energy usage monitoring for 240V/60Hz well pump

Hardware
1

Hello everyone,

I have a well pump and want to understand what my water usage looks like. I tried to find water meters with wireless transmitters (zigbee, wifi, z-wave, etc) but could not find anything which is reliable, fairly accurate and costs less than $50.

So I decided to monitor the usage of the well pump instead - by knowing how many gallons it pumps per minute, I can get approximate consumption of pumped water.

The thing is - well is 240V/60Hz and I could not find any fairly cheap zigbee/wifi monitor.

Then I found this - WiFi Smart Energy Monitor Switch Meter - while it is double the price I was willing to pay for it, I don’t see any alternatives for 240V.

Anyone has used the above meter and integrated it with HA?

2

Have you looked at a shell em?

Shelly EM + 50A Clamp | Shelly Shop USA. I have two monitoring my up/down ac + furnace for power consumption so four entities.

3

Thanks, but it is kinda more expensive than the one I posted, however, I guess with monitoring 2 channels 50A each it comes at $35 each…

How accurate are they especially measuring current per channel separately and in total?

4

They are within 2.5%. I use the entities in utility meters. It matched my fluke meter so I took that as a fair test.

5

I have a 6,500 litre rainwater harvesting tank. I need to monitor when pump is working (it is triggered by falling pipe pressure), water flow, tank depth and general pipe pressure. Therefore I have:

  1. Shelly EM + clamp + contactor (so I can remotely program when pump is off = low tank level etc etc)
  2. 0-5v depth sensor = this allows me to calculate litres in the cylinder (and next job is to calculate rate at which water is used)
  3. 0- 5v pressure sensor to indicate bar pressure of the charged irrigation pressure vessel

At all times I know exactly the state of my system. Water flow is my last luxury to calculate from depth of tank change!

6

I would love to see your config and diagrams.

7

Depth

You need to choose depth and voltage, so that you are never over 3.3v ESP pin limit or what ever ADC you are using. I used ADS1115 for accuracy and could go a bit higher on voltage. You also need to use twisted pairs shielded if long distance and used a buck converter to have 24v, 5v and 3.3v with a common ground. That means all sensors have the same base

Pressure
https://m.aliexpress.com/item/33028576390.html?spm=a2g0n.order_list.0.0.21ef1802al16S0

Ditto same comments as above

ESPHome is great and I can share settings if needed

Current detection
Shelly EM is well documented and my electrician was great in ensuring that the rated contactor met UK regulations. The pump,is rated 4 or 5 amps but the start up induction surge current is close to 14amps. So a contactor is a must.

8

Well the most important question now (that we know the voltage and frequency) is what current your pump is drawing. :zap:

Depending on that the solution can be vary from devices like a sonoff pow r2 (16A rated), sonoff pow r3 (25A rated) up to a pzem004t (100A rated) combined with esp(home). The later might be the most accurate and at the same time maybe even the cheapest but involves a little DIY. :man_factory_worker:

If you take control over the *ware and not only buy hardware you can also implement things like a dry run protection or automatic shut-off after time or when a sensor is triggered. This can all work locally (without wifi/ha) if implemented directly on the esp :rocket:

9

I looked at pump specification and it says

Motor        - 1.5HP 
MaxAmps        -  11.5
Volts          - 230

This tells me that SONOFF POWR3 should be more than enough for this job.

Now one question - do I have to use esp with it? Have no experience with esp.
If the sonoff switch comes with wifi, can’t I import metrics directly to HA?

P.S. Found SONOFF POW Elite at Aliexpress - ordered two - USD $35 with shipping and taxes.

10

If I’m not mistaken AC Motors/Pumps should be oversized in terms of the relay by the factor of 2 because it’s a inductive load and (very simplified spoken) draws 0A one moment and the double of the rated current the other moment (that would be 23A in your case) - the average results on the datasheet (11.5A for you).

By the looks of it as the one linked in my post is rated for max 25A.

Well, afaik (don’t own a powr3) most of the sonoff devices are build around esp’s (for example sonoff basic, sonoff pow r2, …) and often even have a so called “DIY mode” to change the stock firmware for some self-brew (like esphome). How the stock firmware integrates with home assistant I can’t tell because the first thing I do is to own the devices I buy :wink:

By the looks of it this (sonoff pow elite) is only rated for a maximum of 20A (the smaller version only for max 16A).

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