SONOFF 4CH Pro R3 4-Channel WiFi Switch (DIN Rail Mount)
4.5 ★ · 320 reviews
$29.90reference price
View on AmazonWhat is it and what's it for?
It's a 4-channel smart switch that mounts on an electrical panel's DIN rail and replaces manual switches — each channel turns on/off via WiFi, app, voice, or RF remote, no programming needed.
Real-world use cases
- At home: You install it in the panel to control 4 irrigation zones (pumps or valve transformers) from your phone or by voice, with interlock mode so only one zone waters at a time without overlap.
- In a business or workshop: An irrigation installer uses it as the control output in panels where the client wants automation but doesn't want to depend on a custom-programmed microcontroller — standard electrician-grade install, not a hobbyist one.
How to avoid buying the wrong one
- No Arduino or ESP32 programming required — unlike the other 2 relay modules in this catalog, it comes ready to use with the eWeLink app.
- Several buyers report intermittent WiFi drops — a solid router near the panel is worth having before relying on remote control for critical irrigation.
- Interlock mode (one channel on shuts off the other 3) is a real advantage for alternating irrigation zones without adding separate control logic.
The investment takeaway
At $29.90 it costs more than an Arduino relay module (~$8-15), but that premium buys DIN-rail installation, a ready-made app, and voice/RF control with zero programming — worth it if you don't want to get into microcontroller code. If you already know how to program and want the lowest cost per channel, the Arduino modules in this catalog give more for your money.
Field glossary
Terms you'll hear about this equipment
So you can use the right vocabulary with a customer, a supplier, or a manual.
- DIN Rail — Riel DIN
- Una tira metálica ranurada donde se enganchan los componentes de un tablero eléctrico sin tornillos, para que queden ordenados y sea fácil cambiarlos.