How to detect power consumption, not using a smart switch?

I want to monitor how often my sump pump runs. I could do this with a smart plug, detecting when power was being consumed. However, due to the critical nature of the sump pump I am unwilling to connect it to a device which is even capable of turning off.

Does anyone know of something like this? Essentially a smart outlet without the switching capability?

Right now the closest I’ve come is to buy a split core current transformer and measure the circuit draw either at the outlet or the service panel, but that is a lot of work.

You may need to beware of the current draw for any device you put inline also!!

Only other approach to suggest is to measure flow from the pump on the liquid side?

You could use a clamp on current sensor, roll your own ESP to publish readings or use ESPHome.

Edit - see you suggested that above.

There are other sensors but I don’t know of any “smart” ones out of the box.

Just wire a relay in parallel with the pump so every time power is sent to the pump, it also switches on the relay. Then use whatever smart device you like to monitor the status of the relay. ie: Wemos D1 mini, or even a zigbee wireless door sensor hacked to replace the reed switch with wires to the relay

How about a PZEM-004T with an ESP8266 or ESP32 and ESPHome? Basically a current transformer but very easy to wire up and integrated with HA using ESPHome.

For no wiring at all (except a USB charger): an old Android phone strapped to the pump running Sensor Node Free and publishing noise and accelerometer readings via MQTT to HA.

Shelly has some powermeters that work non intrusive with an external clamp around the wire (no idea how you call these in English) even for 3-phase “rotational current” (whatever you call THAT in english). :crazy_face:

Similar to this, assuming the pump is mains, wire the live feed of the pump to the switch input of a Shelly1 (or similar relay) and that will switch on whenever the pump is on.

Is it not better to measure the water level?
Sure it’s great to know the pump is on every now and then, but knowing the water level seems to be more important.

You could build something very simple with just two wires or the more elegant solution is probably a distance sensor.