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.
KWS-302WF specifications:
- 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.
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Do you really want to run your mains tru a cheap chinese device?
Nope…never. Probably doesn’t actually meet electrical code requirements
Probably does, probably doesn’t have paperwork to prove it… The measuring unit /screen is low powered and uses standard components so chances that it makes more noise then CE allows are low. In many countries the code says a lot about electric appliances… but for 1 faze 220/230V units below 16A… nobody cares. Big exception are the States (USA) since with 110V you quickly get to currents that can cause fire… and they’re homes are pretty flammable.
Near everything now are made in china, so…
Unless you live in France or Germany you probably already do… most cheep RCDs and breakers are made in China… This device is made to put on a single circuit and measure your fridge/washing machine/stove…
It’s a very good device and very well manufactured. The quality of mesurment are like a true laboratory instrumentation. It’s as fast as we can catch real time surge current.
How do you monitor the one without wifi, does it have wired ethernet or one if the mesh networking options?
Or is it only good for opening you fusebox and eyeballing the values? (Which all the power meters over here already do)
The user would need to open the fusebox and read what’s written on the display.
Where I live the utility relies on traditional analog power meters located on the street, and mine is about 100 meters from the house, so having something in the house would be beneficial.
This is an alternative, https://www.aliexpress.com/item/1005005241879408.html
and an ESP32 with this library ..
https://www.arduino.cc/reference/en/libraries/pzem004tv30/
Quite accurate upto 100A
There’s no power control what I can see, please update the title. It doesn’t have a relay builtin.
What does “with WiFi and power off” mean? I reckon it’s not super clear, and although I understand it as power control, there may be another explanation.
One does not simply break 63A, so I think they mean power off the display and wifi. But hard to tell, I don’t speak chinese so I can’t ask them…
I suppose it means it has two builtin functions wifi and other power off button on the main display
Hi everyone I purchased kws-302wf Electric protection Circuit breakers. I was shocked to see that the device doesn’t restore itself once turned off due to higher or lower protection values. One has to turn it on remotely or manually. I tried to contact all firms supplier to provide the fix for it but all firms specially tuya under the brand name as the product is being sold replied that they are not the sole manufacturer and that I need to contact the manufacturer. I searched alot but couldn’t find the manufacturer can any one help me on providing me the… Read more »