Sonoff SPM-4Relay 4-channel smart relay module (Need SPM-Main)

The Sonoff SPM-4Relay is a 4-channel smart relay module designed to work in conjunction with the Sonoff SPM-Main unit, forming part of Sonoff's Smart Stackable Power Meter system. This setup is ideal for applications requiring detailed energy monitoring and control across multiple circuits, such as in commercial buildings, server rooms, or industrial settings.

🔧 Key Specifications

Model: SPM-4Relay

Power Supply: 100–240V AC, 50/60Hz

Maximum Load: 20A per channel; 80A total across all channels

Communication Interface: RS-485 (connects to SPM-Main)

Dimensions: 250 × 90 × 66.5 mm

Mounting: DIN rail compatible

Operating Temperature: -10°C to +40°C

Housing Material: Flame-retardant PC V0.

⚙️ Features

Four Independent Channels: Each capable of handling up to 20A, allowing for control of high-power devices.

Real-Time Energy Monitoring: Track voltage, current, and power consumption for each channel via the eWeLink app.

Overload Protection: Automatically disconnects power to prevent damage when thresholds are exceeded.

Remote Control: Manage and monitor connected devices remotely through the eWeLink app.

Stackable Design: Connect up to 32 SPM-4Relay modules to a single SPM-Main unit, enabling control of up to 128 channels.

Secure Communication: Utilizes RS-485 for stable, long-distance data transmission between modules.

🛠️ Installation & Setup

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

2. Mounting: Install the SPM-4Relay module onto a DIN rail within your electrical cabinet.

3. Wiring: Connect the module to the SPM-Main unit using RS-485 communication cables.

4. Power On: Restore power and use the eWeLink app to pair and configure the module.

Note: The SPM-4Relay requires an SPM-Main unit for operation, which is sold separately.

📦 What's in the Box

1 × Sonoff SPM-4Relay Module

User Manual