Is it true that "no relay" plugs are suitable for monitoring energy use in washing machine, fridge freezer, tumble drier and so on (ie inductive loads)?
I've read in a couple of places that people are doing this. This seems questionable, but idk enough myself. If not, what do folk use to monitor power in these cases?
#HomeAssistant #HomeAutomation
@existentialist thanks. I haven't tried them yet but these are "no relay" just for energy monitoring.
They sell them as for stuff that needs to be always on.
https://www.athom.tech/blank-1/no-relay-power-monitoring-uk-plug-for-esphome
UK Smart Power Monitor (No Relay Version) Designed for Always-On Devices · ESPHome · ESP8285 + HLW8032 This smart plug is specially designed for devices that must stay online — such as NAS, servers, routers, network hardware, mini PCs, and smart home hubs.Unlike standard smart plugs, this model features no relay, ensuring 100% uninterrupted power, with zero risk of accidental shutdown.It provides accurate real-time energy monitoring, powered by the HLW8032 metering chip and ESP8285 Wi-Fi MCU. Pre-flashed with ESPHome, it integrates seamlessly with Home Assistant and automation platforms for power analysis and device state detection. 🔍 Ideal For Always-On Devices✔ NAS / Home Server✔ Router & Switch✔ Network Storage & Gateway Devices✔ Smart Home Hub / Raspberry Pi✔ Mini PC / Thin Client✔ Industrial or Network Monitoring EquipmentNo relay = no switching = zero risk of power interruption.Perfect for 24/7 operation and long-term monitoring. 🚀 Key Features 🛑 No Relay – Guaranteed continuous power 🔍 Designed for servers & network devices ⚡ HLW8032 energy metering for high accuracy 📶 ESP8285 Wi-Fi microcontroller 🧠 ESPHome pre-flashed – instantly works with Home Assistant 📈 Detect device status via power usage (automation-friendly) 🔄 OTA firmware upgrade support ☁ Fully local control – no cloud needed 📦 Specifications Parameter Description MCU ESP8285（2MB） Wi-Fi Energy IC HLW8032 Relay None – guaranteed no interruptions Firmware ESPHome pre-installed Voltage 100～240V AC Plug Type UK Protocols ESPHome API / MQTT Current 16A Supports OTA Yes 🧠 Automation Possibilities Detect if NAS / server is running or offline via power usage Track long-term power consumption trends Send alerts if router draws no power (failure detection) Measure idle vs active power of network equipment Home Assistant energy dashboards Power efficiency optimization 🧾 Why This Plug? Specifically built for devices that must not lose power No relay — no risk of accidental shutdown ESPHome-ready for instant smart home integration Accurate energy monitoring with HLW8032 Ideal for IT labs, data monitoring, and smart home setups Perfect for 24/7 non-stop operation The measurement error of active power about 0.2%The measurement error of effective current is 0.5%The measurement error of effective voltage is 0.5% Yaml File Download: https://github.com/athom-tech/athom-configs/blob/main/athom-without-relay-plug.yaml GPIOs: GPIO3： CSE7766 RxGPIO5： Button1GPIO13 ：LedLinki Steps to Install : *Power on the plug*Use your phone/computer search the SSID: a t ho m_xxxxxxx*Connect it and set the SSID and password of your 2.4G WiFI *Go your Home Assitant find the new device and complete installation
@existentialist there's also this, suggested by @codechimp in another reply:
@happyborg I'm using Shelly PM Mini's which just monitor.
I've mounted them inline on short extension cords with a suitable box to keep them safe.
Very wary of relay plugs for anything critical, both from electrical safety and also accidental switch offs.
RE: https://mastodon.online/@codechimp/116555807939053016
@happyborg That's perfect! It'd be nice to find a UK/European supplier, but it's good to know they even exist.
happyborg
Stephen
Rudy Gnodde
Andrew
Uptime: ∞