Sonoff SPM-Main Smart Stackable Power Meter Main Unit Connect up to 32 SPM 4Relays Support Micro SD up to 32GB LAN control Ethernet Connection 2.4GHz

This power meter realizes intelligent management with overload protection, electricity monitoring, and statistics. RS-485 communication enables "intelligent stacking" The SPM-Main communicates with the cloud via Ethernet or WiFi and communicates with the SPM-4Relay via RS-485, which allows stable and multi-terminal long-distance data transmission. Once overload protection is enabled, there is no need to worry about electrical appliances burning out, which helps remove potential safety hazards. In addition, it is also possible to set the activated overload delay to avoid spurious triggers. One SPM-Main can be connected to 32 SPM-4Relays, 128 isolated channels, each up to 20A. Each SPM-4Relay has 4 isolated channels to help the tenant solve the problem of sharing the electric charge. Each channel can support a maximum current of 20A, without fear of high-power loads. You can install SPM-Main and SPM-4Relays step by step by following the user manual. With the guide rail, they can be easily installed in the right place to make your room simple and tidy