SONOFF SPM Smart WiFi Power Meter 20A – Stackable Energy Monitor with Overload Protection, eWeLink App Control & SD Card Data Logging

🔌 Expandable System – Control Up to 32 SPM-4Relays
Connect 1 SPM-Main unit with 32 SPM-4Relays (128 total channels!) for full-scale energy management in homes, offices, or industrial setups.

📊 Real-Time Power Monitoring via eWeLink App
Track voltage, current, and live power consumption remotely from your smartphone—no guesswork, just precise energy data.

⚡ High 20A/Gang Load Capacity
Each channel handles up to 20A, supporting heavy-duty appliances without risk of overloading.

📡 Stable RS-485 Communication
SPM-Main links to SPM-4Relays via industrial-grade RS-485 for long-distance, multi-device data transfer without interference.

🛡️ Built-In Overload Protection
Auto-shutoff triggers when limits are exceeded—prevents circuit damage and keeps connected devices safe.


 

SONOFF Stackable Power Meter realizes smart management with overload protection, metadata monitoring and electricity statistics.The SPM-Main communicates with the cloud through Ethernet or WiFi, and communicates with the SPM-4Relays through RS-485, which allows for multi-terminal and stable long-distance data transmission. Want to know the power consumption changes of each stall? Want to realize the unified management of the whole shopping mall? By checking eWeLink App on your mobile phone, you can monitor the electricity usage without leaving home. Through the eWeLink App, you can obtain the power consumption through a touch. Once the overload protection is enabled, you do not need to worry about electrical appliances being burned out, which helps remove potential safety hazards. In addition, you can also set the overload delay activated to avoid spurious triggering.One SPM-Main can be connected 32SPM-4Relays. Each SPM-4Relay has 4 isolated channels to help the tenant to solve the problem in electric charge sharing. Each channel can support maximum current of 20A, no fear of high power load. Get Over 180-day of Energy Usage Data Available SD card local storage. You can insert the SD card into SPM-Main to download and check over 180 days of your energy usage history at any time of the day through HTTP API. No need to worry about missing the important information.

Package includes :

• Main Unit/4-Relay
• 50cm RVVSP
• User Manual

Documents

• User Manual