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Tuya - WiFi energy meter with 40A relay and LCD display - DIN rail - KWS-303WF
KWS-303WF WiFi energy meter with a 40 A relay and LCD display, for DIN rail.
- Voltage, current, power and energy measurement in a single-phase circuit
- Voltage, current and temperature protections
- Control in the Smart Life and Tuya Smart app
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WiFi energy meter with 40 A relay
KWS-303WF is a DIN rail WiFi energy meter with a 40 A relay and a color LCD. It measures voltage, current, power, frequency, power factor and energy in a single-phase circuit, and you can see the results live on the screen. The relay lets you switch the circuit on and off remotely.
The meter connects to WiFi and works with the Smart Life and Tuya Smart apps, where you can view charts of voltage, current, power, energy and temperature. The included external sensor reads temperature, and you set protection thresholds in the app or with buttons.
KWS-303WF energy meter with a color LCD display
40 A
rated current of the built-in relay
12 kW
upper limit of the power measurement range
-20 °C to 150 °C
measurement range of the external temperature sensor
99 days
maximum timer countdown time
Is it the right choice for you?
A good choice if:
- You want to see the circuit's energy consumption in the app and in the distribution board
- You need to switch off the circuit remotely with a 40 A relay
- You want to set your own voltage, current, power and temperature thresholds
Consider another option if:
- The circuit draws more than 40 A: Tongou TO-Q-SY2-JWT with a 63 A relay
- You only need a clamp-on CT measurement: Tongou TO-Q-SA1 with a 50 A transformer
Fun fact
A meter that enforces its own energy limit
In addition to voltage and current protection, the KWS-303WF has an energy usage limit: once the set number of kilowatt-hours is exceeded, the relay switches off the circuit automatically.
Source: KWS-303 manual (EN)
Frequently asked questions
How do I connect the KWS-303WF meter to the app?
On the main screen, hold "+" until the WiFi icon starts flashing, then add the meter in the Smart Life or Tuya Smart app. The meter requires 2.4 GHz WiFi.
What circuit protections can you set in the meter?
The meter has overvoltage, undervoltage, overcurrent, overload and temperature protection, plus an energy limit. You set the thresholds in the app or with the buttons.
How does the meter behave after a power outage?
The meter remembers its data, and the relay state after power returns depends on the setting: it can be on, off, or the same as before the outage.
Package contents
- 1 x KWS-303WF energy meter
- 1 x External temperature sensor
Technical specification
| Parameter | Value |
|---|---|
| Manufacturer code | KWS-303WF |
| Type | single-phase energy meter with relay, DIN rail mounting |
| Supply voltage | 85 V to 290 V AC, 50 Hz to 60 Hz |
| Rated current | 40 A |
| Current measurement range | 0 A to 40 A |
| Power measurement range | 0 kW to 12 kW |
| Energy measurement range | 0 kWh to 9999 kWh |
| Power factor | 0.00 to 1.00 |
| Temperature measurement range | -20 °C to 150 °C (external sensor) |
| Measurement accuracy | ±1 % |
| Overvoltage protection | threshold 130 V to 290 V |
| Undervoltage protection | threshold 85 V to 220 V |
| Overcurrent protection | threshold 0 A to 40 A |
| Overload protection | threshold 1 kW to 12 kW |
| Other functions | energy limit, temperature protection, timer up to 99 days, data memory after power loss |
| Display | color LCD, brightness 0 % to 100 %, 180° rotation |
| Connectivity | WiFi 2.4 GHz |
| App | Smart Life, Tuya Smart |
| Dimensions | 82 x 50 x 24 mm |
| Name | Value |
|---|---|
| Smart Home | Energy meter |
| Communication | WiFi |
| Width | 8.5 cm |
| Height | 8 cm |
| Depth | 2.5 cm |
| Weight | 0.112 kg |
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30 days to return, without giving a reason
If the product does not meet your expectations, you have 30 days from receiving the parcel to withdraw from the contract. The product only has to be complete. The right of return belongs to consumers (a purchase unrelated to business activity).
Complaints
If the product turns out to be faulty, you can make a claim under the guarantee or the statutory warranty. We handle claims without delay, at the latest within 14 working days of receiving the report together with the goods.
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