Modular smart switch hub with energy metering | up to 128 channels | 50mA | 100-240V | DIN | Wi-Fi | Ethernet | SONOFF | SPM-MAIN

Code: SPM-MAIN

Barcode: 6920075776973

Inquire about this item

Add to compareRemove from comparison Compare goods (0)

Add to wishlist

Price 44.80 € VAT incl.
( 37.02 € VAT excl. )

Add to cart

SONOFF SPM-Main is the main unit of a modular energy metering system for DIN rail (100–240 V AC, Wi-Fi + Ethernet, RS-485). It controls up to 32 SPM-4Relay modules – up to 128 channels of 20 A. microSD up to 32 GB, HTTP API. The SPM-4Relay module is sold separately.

Product description

Modular smart switch hub with energy metering | up to 128 channels | 50mA | 100-240V | DIN | Wi-Fi | Ethernet | SONOFF | SPM-MAIN

SONOFF SPM-Main is the main unit of a smart modular energy metering system for DIN rail. It controls and reads up to 32 SPM-4Relay modules – up to 128 channels in total with current, voltage, power and energy measurement.

Key idea:
The SPM system shows how much energy each circuit in the distribution board uses and lets you switch it on or off remotely. SPM-Main is the brain of the system – without at least one SPM-4Relay module it does not control any circuits.

Channels
up to 128 (32 × SPM-4Relay)

Connectivity
Wi-Fi 2.4 GHz and Ethernet

Data
microSD up to 32 GB, ~180 days

Mounting
DIN rail

How it works

SPM-Main is mounted on the DIN rail in the board and daisy-chained via RS-485 to SPM-4Relay modules. Each SPM-4Relay has 4 channels, each up to 20 A.

The main unit connects to the network via Wi-Fi or Ethernet and sends data to the eWeLink app: real-time current, voltage, power and consumed energy for each channel.

Up to 180 days of consumption history are stored automatically on a microSD card (8–32 GB SDHC). Data can be read via HTTP API and used in energy monitoring systems.

Why choose SPM-Main?
SPM-Main turns a standard board into a smart one: each circuit's consumption is visible separately, excessive loads are found quickly, and circuits can be controlled remotely and by schedule.

Technical specifications

Product type	Main unit of a modular energy metering system (DIN)
Manufacturer / model	SONOFF SPM-Main
Supply voltage	100–240 V AC, 50/60 Hz
Max. current consumption	50 mA
Network connectivity	Wi-Fi IEEE 802.11 b/g/n 2.4 GHz, Ethernet (LAN)
Module bus	RS-485
Connectable modules	up to 32 × SPM-4Relay (up to 128 channels)
Channel current (SPM-4Relay)	up to 20 A
Data storage	microSD 8–32 GB SDHC (not included), up to 180 days
Integrations	eWeLink, HTTP API, LAN mode
Mounting	35 mm DIN rail
Housing	PC V0
Operating temperature	-10 °C … +40 °C
Operating humidity	5–95 % RH, non-condensing
Dimensions / weight	142.5 × 90 × 66.5 mm / 214 g

Main functions

Energy metering – current, voltage, power and consumed energy per channel.
Remote control – each channel can be switched on or off in the app.
Scalability – up to 32 SPM-4Relay modules, up to 128 channels in total.
Data history – up to 180 days of consumption data on a microSD card.
Wi-Fi and Ethernet – stable connectivity even where Wi-Fi is weak.
HTTP API – data readout for other systems.

Where is it used?

Shopping centres and shops
Office buildings and business centres
Apartment building and house boards
Production and warehouse premises
Energy metering of rented premises
Monitoring of solar and heating systems

Use by need

For facility managers.
Consumption of each circuit visible, plus remote control.

For electrical designers.
A modular DIN system expandable to 128 channels.

For integrators.
Ethernet, LAN mode and HTTP API for data.

Practical use

An office board has 12 circuits: lighting, air conditioners and sockets. With SPM-Main and three SPM-4Relay modules, the manager sees which circuit uses the most energy, and the air conditioner circuits are switched off after working hours by schedule.

Pros

Up to 128 channels in one system
Metering for each channel separately
Wi-Fi and Ethernet connectivity
Data history on microSD card
HTTP API and LAN mode

Cons / limitations

Does not control circuits without an SPM-4Relay module
microSD card not included
Needs space on the DIN rail in the board
System design requires an electrician

Safety and installation notes

Installation in the board must be done only by a qualified electrician with the power disconnected.
The SPM system is not a protective device – do not use it instead of circuit breakers or fuses.
The load on each SPM-4Relay channel must not exceed 20 A.
Install in a dry, closed distribution board.
Run the RS-485 line according to the manufacturer's diagram and observe polarity.

Quick selection guide

Up to 128 channels

Wi-Fi + Ethernet

RS-485

microSD up to 32 GB

DIN rail

HTTP API

Suitable when you need:

to meter and control many circuits in one board
to track energy consumption by circuit
to integrate data into other systems

Check before use:

that you have ordered at least one SPM-4Relay module
that there is DIN rail space in the board
that channel loads do not exceed 20 A
that Wi-Fi or Ethernet is available at the board

Important reminder: SPM-Main is only the main unit – controlling and metering circuits requires at least one SPM-4Relay module, and the system does not replace protective devices.

FAQ

Does SPM-Main work on its own?
No. It is the main unit – at least one SPM-4Relay module is needed to meter and control circuits.

How many channels can be connected?
Up to 32 SPM-4Relay modules with 4 channels each – up to 128 channels in total.

What current does one channel support?
Each SPM-4Relay channel – up to 20 A.

Is Wi-Fi required?
No, SPM-Main can also be connected via an Ethernet cable – handy in metal enclosures.

Where is the data stored?
On a microSD card (8–32 GB SDHC, not included) for up to 180 days, and in the eWeLink app.

Can it be integrated with other systems?
Yes, data can be read via HTTP API, and LAN mode is supported.

Modular smart switch hub with energy metering | up to 128 channels | 50mA | 100-240V | DIN | Wi-Fi | Ethernet | SONOFF | SPM-MAIN

SONOFF SPM-Main is the main DIN unit of a modular energy metering system: up to 128 channels with metering and remote control, Wi-Fi and Ethernet, data history and HTTP API.

Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

Attributes

Manufacturer

Sonoff

CE certificate – a guarantee of safety, quality, and compliance

This product is marked with the CE label, which confirms that it complies with all applicable European Union directives and regulations. CE marking is not just a formality – it is an important indicator of quality and safety, ensuring that the product has been properly assessed, tested, and can be safely used throughout the EU market.

CE certification means that the product has been evaluated according to the main criteria:

Safety requirements – ensures that the product does not pose a risk to the user or the environment
Electromagnetic compatibility (EMC) – the device does not interfere with other equipment and is resistant to external disturbances
Environmental standards – complies with current ecological and material usage requirements
Operational reliability – the product is suitable for long-term use according to its intended purpose

CE marking allows this product to:

be legally supplied and used in all European Union countries
ensure a high level of quality and safety
be used in residential, commercial, and industrial environments

The CE mark is a declaration of the manufacturer’s responsibility, confirming that the product complies with all applicable standards and has been assessed according to EU legislation.

What does this mean for you as a buyer?

Safe use in everyday activities
Reliable performance and reduced risk of failure
Compliance with EU standards and requirements
Suitability for professional solutions

Customer reviews

Love it? Share your thoughts in a review!

Write Review

Related products

Smart relay switch | 4-channel | 40A | 8800W | 100-240V | Wi-Fi | SONOFF | 4CHPROR3

Code: SONOFF-4CHPROR3

SONOFF 4CHPROR3 is a 4-channel Wi-Fi relay with an RF 433 MHz receiver (10 A per channel, 40 A / 8800 W total). Three operating modes – self-locking, inching and interlock – for lighting, gates and pumps. Controlled with eWeLink, Alexa, Google Assistant and an RF remote.

Price 37.80 € VAT incl.

( 31.24 € VAT excl. )

Add to cart

Modular | smart | digital energy meter | 16A | 100-240V | DIN | Wi-Fi | SONOFF | POW Elite | POWR316D

Code: SONOFF-POWR316D

SONOFF POWR316D (POW Elite 16A) is a smart Wi-Fi relay with energy metering and an LCD display, mounted on a DIN rail. It switches loads up to 16 A (3680 W), shows power, voltage, current and kWh, and supports overload limits, schedules, eWeLink, Alexa and Google Assistant.

Price 23.40 € VAT incl.

( 19.34 € VAT excl. )

Add to cart

Modular | smart remote switch | 4-channel expansion module | with energy metering | 80A | 100-240V | DIN | Wi-Fi | SONOFF | SPM-4Relay

Code: SPM-4Relay

SONOFF SPM-4Relay is a 4-channel expansion module with energy metering and a relay for each line (20 A per channel, 80 A total). It mounts on a DIN rail, connects to SPM-Main via RS-485, and data and control are in the eWeLink app.

Price 74.80 € VAT incl.

( 61.82 € VAT excl. )

Add to cart

Smart remote switch | 10A | 2200W | 100-240V | Wi-Fi | ZigBee | SONOFF | BASICZBR3

Code: SONOFF-BasicZBR3

SONOFF BASICZBR3 is a Zigbee 3.0 relay (10 A, 2200 W) for controlling lamps and appliances, wired inline in the cable. It works via a Zigbee hub (ZBBridge-P, NSPanel Pro, iHost), strengthens the network as a repeater and supports eWeLink and Home Assistant.

Price 15.80 € VAT incl.

( 13.06 € VAT excl. )

Add to cart

Smart Wi-Fi plug | plug-in socket | 1xSchuko | 2200W | 10A | 100-240V | with timer function | white | SONOFF | S26

Code: SONOFF-S26

SONOFF S26 is a smart Wi-Fi plug with a Schuko connection (10 A, 2200 W). It plugs into a socket and lets you control an appliance by phone, voice and schedule via eWeLink, Alexa or Google Assistant. No energy metering.

Price 16.40 € VAT incl.

( 13.55 € VAT excl. )

Add to cart

Zigbee hub (gateway) | Wi-Fi 2.4 GHz | Zigbee 3.0 | up to 128 devices | 5V 1A | SONOFF | ZBBridge-P

Code: SONOFF-ZBBridge-P

SONOFF ZBBridge-P (Zigbee Bridge Pro) is a Zigbee 3.0 hub with 2.4 GHz Wi-Fi for up to 128 devices. It connects SONOFF sensors, relays and thermostats in the eWeLink app and has security modes and a buzzer. Powered by 5 V, 1 A via Micro USB.

Price 21.40 € VAT incl.

( 17.69 € VAT excl. )

Add to cart
Alternative products

Smart | Outdoor video surveillance IP camera 2MP | 1080p | IP65 | Wi-Fi 2.4 GHz | RJ45 | R9044 Woox

Code: R9044

The Woox R9044 is a wired outdoor 1080p IP camera with an IP65 housing, 104° view and IR up to 10 m. It connects via Wi-Fi 2.4 GHz or an RJ45 cable, records to microSD up to 128 GB and is controlled in the WOOX Home app.

Price 67.00 € VAT incl.

( 55.37 € VAT excl. )

Add to cart

Smart | remote water valve controller | 12V | 1.6 MPa | Wi-Fi | Tuya | NOUS-L3 | 5907772033951

Code: NOUS-L3

NOUS L3 smart remote water valve controller is a practical solution that allows you to open or close a water valve remotely via a smartphone. The device operates via a 2.4 GHz Wi-Fi connection, is controlled through the Nous Smart Home app, and is compatible with Amazon Alexa and Google Assistant voice assistants.

This controller is especially useful where it is necessary to automate water supply, reduce the risk of water leakage, or conveniently control water supply according to a schedule. It can be used for controlling a building’s water inlet, irrigation systems, filling water tanks, swimming pools, or drinking troughs.

Price 37.89 € VAT incl.

( 31.31 € VAT excl. )

Add to cart