Hey there,
I am running a couple of servers at home. I would like to monitor energy consumption for each machine individually. I already have a Sonoff PoW R2 up an running, but I would really like a “plug” housing rather than wires going in and out of the box.
Also I don’t need the switching part, because I will never remotely switch the mains of these machines on and off. To be honest, actually I don’t even want the plug to be able to cut off power so that I dont switch off my server by accident or malfunction. I already found the Shelly Plug S, but its rather expansive (compared to Sonoff Pow R2) and also has a relay inside.
So are there any reliable, HA-compatible, non switching power meter plugs for around 10 bucks out there? Oh, I almost forgot, I would need them with German (EU Type-F) plug design.
You could use ESPhome and a clamp on CT to monitor the supply to the server
Thank you for your reply!
No, I don’t want some diy solution, I could have done that already. Also, measuring only current via clamp is useless (not precise) without measuring voltage at at least one point in my home.
I want a ready to use PLUG !
You can also measure voltage with the ESP…
But anyway, to go with a plug, you are most likely always going to find that an off the shelf product will incorporate the option to switch on/off. If you don’t want to switch it off, then simply don’t. If you have no automations to control the switch part of the plug and no GUI for said switch, then it will stay on.
Well, I’ve been playing around with the Sonoff pow r2 running Tasmota. And every time I change the config of the Tasmota Firmware, the device reboots and I hear the relay click, which would hard reset my servers.
That is easily resolved using the correct poweronstate.
Why change the firmware once it’s up and running how you want it…?
Sorry to resurrect an old post but I’m looking to do the same. I want to detect when my crawlspace sump pump turns on as well as monitor the energy usage on my dehumidifier but I’m fearful that a switching plug may inadvertently turn off the devices, which I obviously don’t want. Did you come up with a viable solution?
I use a Shelly PM on my sump pumps that are not hooked up to an external switch for exactly this purpose. I created a binary sensor that indicates when the pump is running based on the current power use and I count the daily cycles with a history-stats sensor.
You can disable the Shelly PM’s UI power switch in the integration settings so it can’t be turned off in the UI and you’ll just have to restrain yourself from turning it off in the Shelly app 
Further to what Jason has said above, you can create an automation that triggers on the switch being turned off and then turns it back on, just in case something was to turn it off.
I’m looking for the same sort of thing, but specifically with an in-wall outlet. I found this related Reddit discussion.
I’d like to have in-wall power monitoring without the possibility of the switch getting turned off. In particular, I’d like to monitor a refrigerator outlet.
Disabling the switch portion in Home Assistant is an option, I suppose, but I’d like to have a higher assurance the outlet/receptacle stay powered on.
You could buy a smart plug with a switch, and then rewire it internally to bypass the relay?
No need. By now Shelly has several relay-less products. These are bor ready to use plugs, but come in the form of normal shelly relays (without a relay inside)