Sonoff 4CHR3 is a 4-gang Wi-Fi Smart Switch with optional RF433 Connectivity

ITEAD Studio introduced Sonoff 4CH 4-gang WiFi + RF switch in 2017 with a DIN rail enclosure, compatible with eWelink Android/iOS app, and offering three modes of operations selectable from physical switches on the unit:

Self-locking mode – Each relay can be turn on and off independently.
Interlock mode – Only one of the relay can be turned on at a given time. For example if R1 is on, and your press R2 to turn it on, R1 will automatically turn off
Inching mode – A button press on the unit, mobile app, or RF/WiFi remote control will turn on the relay for X seconds as defined by K6 “delay” switch within a 0.5 to 3600 seconds range.

The company has now launched the similar SONOFF 4CHR3 4-gang WiFi switch and 4CHPROR3 model that adds 433MHz connectivity, with the main difference again the previous generation being the ability to select modes of operation right from eWelink mobile app.

Sonoff 4CHR3 & 4CHPROR3 specifications:

Connectivity- 2.4GHz 802.11b/g/n WiFi 4; 4CHPROR3 only: 433 MHz
Voltage Range
- 4CHR3 – 100-240V AC 50/60Hz
- 4CHPROR3 – 100-240V AC 50/60Hz; DC: 9-23V
Max. Load
- 4CHR3 – 10A/2200W per gang; 16A/3500W total
- 4CHPROR3 – 10A/2200W per gang; 40A/8800W total
Dimensions – 145 x 90 x 34 mm (PC V0 enclosure)
Temperature Range – -10ºC to +40ºC
Humidity – 5%-95%RH, Non-condensing
Certifications – FCC & CE

Another difference against 4CHR2 is that the connectors are now fully covered for increased safety. The comparison below shows 4CHR2’s modes could already be controlled from eWelink app, but not 4CHPROR2.

Just like any other eWelink controlled devices, 4CHR3 / 4 CHPROR3 smart switches can also be controlled via voice commands through Alexa or Google Home smart assistants.

Sonoff 4CHR3 is up for pre-order for $18.50, and 4CHPROR3 for $28 on ITEAD store, and shipping is scheduled to start on May 6. Note that while 4CHPROR3 supports RF remote, it does not ship with one, but you can purchase one separately for $4.50.

Thanks to Andreas for the tip.

Jean-Luc Aufranc (CNXSoft)

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.