KWS-302WF is an inexpensive WiFi power meter with a color display and power control that is suitable for the whole house since it can handle up to 63A/17kW and supports DIN Rail mounting in a fuse box or cabinet.
Installation is made through the neutral and live wires, and the display shows voltage, current, power, energy consumption, power factor, frequency, and temperature through an external temperature probe. Multiple KWS-302WF can be monitored and controlled through a mobile app which may make suitable suitable for apartment buildings as well.
- Voltage range – 170-270V
- Current range – 0 to 63A
- Power range – 0 to 17 kW
- Energy range – 0 to 9999 kWh
- Timer range – 0 to 999 hours
- Temperature Range – -20 to +150°C (that is for the temperature sensor, and not the actual operating temperature range…)
- Frequency Range – 50 to 60 Hz
- Power Factor – 0 to 1
- WiFi connectivity for mobile phone control (on/off) and monitoring
- Power off memory (again not 100% clear, but I suppose that means it can remember the last state in case of a power failure)
- Safety – Under voltage protection, overvoltage protection
- Dimensions – Fits in a 78.8 x 65.6 x 66mm volume
There are also two other models the KWS-302L without WiFi and the KWS-302 without WiFi and under/over voltage protection. The KWS-302WF WiFi power meter can be controlled through the Smart Life app for Android and iOS which should mean it integrates a solution made by Tuya.
I could not find anybody who hacked the device or even just did a teardown, but there’s a YouTube review in Russian below (enabled close caption with auto-translation) that shows the device in action and compares results using multimeters to measure voltage and current. While the values are not exactly the same, the reviewer said it was close enough, except for the frequency (49 Hz).
Warning! There are always safety and legal (insurance) issues with devices that connect directly to the mains, and that’s especially true for the KWS-302WF power meter due to the high current going through the device. There’s no mention of safety certifications like TUV, UL, or ETV either. So make sure you know what you are doing and/or contact a professional for installation and advice.
With that out of the way, I first found the KWS-302WF WiFi power meter on Banggood for $19.99 including shipping, and the “no WiFi models” are sold for $12.99 and $16.99 respectively. Alternatively, you’ll also find it on Aliexpress for $13.26 plus shipping, with the KWS-302L model going for $9.93, and the KWS-302 for $7.60…
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.