Sonoff Smart Stackable Power Meter (SPM)

The Sonoff SPM-Main is the central controller in Sonoff's Smart Stackable Power Meter (SPM) system, designed for advanced energy monitoring and management across multiple circuits. It's particularly suitable for environments like office buildings, shopping malls, server rooms, and industrial facilities.

🔧 Key Specifications

Model: SPM-Main

Power Supply: 100–240V AC, 50/60Hz

Network Connectivity: Wi-Fi (2.4GHz, IEEE 802.11 b/g/n) and Ethernet

Communication with Relays: RS-485 (supports up to 32 SPM-4Relay modules)

SD Card Support: MicroSD (8GB–32GB, SDHC) for local data storage

Dimensions: 142.5 × 90 × 66.5 mm

Mounting: DIN rail compatible

Operating Temperature: -10°C to +40°C

Material: Flame-retardant PC V0

⚙️ Features

Scalable Monitoring: Connect up to 32 SPM-4Relay modules, each with 4 channels, allowing management of up to 128 circuits.

Real-Time Data: Monitor voltage, current, and power consumption for each channel via the eWeLink app.

Overload Protection: Safeguards devices by disconnecting power when thresholds are exceeded.

Local Data Storage: Store up to 180 days of energy usage data on a MicroSD card, accessible via HTTP API.

Remote Control: Manage and monitor circuits remotely through the eWeLink app on Android and iOS devices.

LAN Mode: Continued operation and control within the local network if internet connectivity is lost.

Integration: Compatible with the eWeLink ecosystem; REST API support available.

📦 What's in the Box

1 × Sonoff SPM-Main Unit

1 × 50cm RVVSP Cable

1 × User Manual

Note: SPM-4Relay modules and MicroSD card are sold separately.

🛠️ Installation & Setup

1. Power Off: Ensure the main power supply is turned off before installation.

2. Mounting: Install the SPM-Main unit onto a DIN rail within your electrical cabinet.

3. Wiring: Connect the SPM-Main to SPM-4Relay modules using RS-485 communication cables.

4. Network Connection: Connect to your network via Wi-Fi or Ethernet.

5. SD Card Installation (Optional): Insert a MicroSD card (8GB–32GB) for local data storage.

6. Power On: Restore power and use the eWeLink app to complete setup and configuration.

Ensure all wiring complies with local electrical regulations and consider consulting a professional electrician for installation.

🔗 Resources

Official Product Page: Sonoff SPM-Main

User Manual: SPM-Main & SPM-4Relay Documentation