Description
The SONOFF SPM-Main is the main unit of the SONOFF Smart Stackable Power Meter (SPM) system. It connects to your network over Wi-Fi 2.4GHz or Ethernet and controls up to 32 SPM-4Relay units over RS-485, for up to 128 monitored channels from one hub.
Use the eWeLink app to switch each channel and track real-time current, voltage and power. Its microSD card slot (8–32GB SDHC) stores over 20 years of power data and up to 20,000 operation logs per device, and you can quickly export consumption reports from the card.
Note: the SPM-Main works together with the SPM-4Relay. It must be connected to at least one SPM-4Relay to function.
Key Features
- Central unit of the SONOFF Smart Stackable Power Meter system
- Connects up to 32 SPM-4Relay units, for up to 128 channels
- Wi-Fi 2.4GHz and Ethernet connectivity
- RS-485 communication with the relay units
- microSD storage (8–32GB SDHC): over 20 years of power data and up to 20,000 operation logs per device
- Quick export of consumption reports via the SD card
- Real-time current, voltage and power monitoring in the eWeLink app, with LAN control
- Overload protection on every SPM-4Relay channel (20A per channel)
- DIN rail mounting in distribution boards and control panels
Works With
Technical Specifications
| Specification |
Details |
| Model |
SPM-Main |
| System |
SONOFF Smart Stackable Power Meter (SPM) |
| Wi-Fi |
802.11 b/g/n 2.4GHz |
| Wired Network |
Ethernet |
| Communication with Relays |
RS-485 |
| Maximum Expansion |
Up to 32 SPM-4Relay units (128 channels) |
| Micro SD Card Storage Range |
8GB–32GB (SDHC) |
| Input Voltage |
100-240V AC 50/60Hz |
| Installation |
DIN rail |
| App |
eWeLink |
| Color |
White |
| Shell Material |
PC V0 |
| Operating Temperature |
-10°C ~ 40°C |
| Dimensions |
142.5 × 90 × 66.5 mm |
Why Choose the SONOFF SPM-Main?
- One hub for multi-circuit or building-wide energy monitoring
- Scales with your installation, from 4 up to 128 channels
- Wired Ethernet or Wi-Fi for a stable connection
- Long-term local records on microSD for energy reports
Downloads
⬇ Download User Manual (PDF)
Warranty: 12-month warranty from the Official Distributor.
