Smart Energy Meter Selection Guide: Choosing the Right SPM Model for Your Energy Management

Aug 15, 2023 | Features

In today’s climate of increasing electricity costs, both individuals and businesses are actively seeking ways to reduce their electric bills. Energy metering and monitoring has emerged as a viable solution to address this need, enabling users to identify areas of unnecessary energy consumption, increase energy efficiency and lower energy cost.


SPM is the product series name of Bituo’s revolutionary smart meter (smart energy sensor) with product highlights of compact size and versatile communication options. It empowers users to track essential metrics such as current, voltage, power, and energy consumption, providing valuable insights into their electricity usage. With an SPM, customers can fine-tune their energy use patterns, ultimately resulting in reduced energy use and electric bill.


Bituo offers various SPM models, each catering to distinct needs and requirements, ranging from voltage phases to installations, and from communication protocols to cloud options. In this comprehensive guide, we aim to explain the naming sequence of SPMs and help customers select the most suitable model for their specific use cases, by introducing the unique features and benefits of each model.


Understanding the Naming Sequence

SPM models adhere to the naming convention “SPMXX-XXXX,” with each “X” or “XX” representing a range of alphanumeric options indicating unique attributes and product characteristics. The subsequent section provides an in-depth breakdown of the significance behind each digit.

A Portion of SPM01/02 models

A Portion of SPM01/02 models


1. SPMXX-XXXX: Platform Number

The initial “XX” within the naming sequence denotes the platform identifier for the SPM models. Every platform has its unique mechanic, electronic and firmware design, aiming to meet different customer requests.

01: Platform 1 (1P+N, smart metering up to 63A)

SPM01 can be used to monitor electrical data in real-time in single-phase electrical systems. With its large through hole of 9.8mm diameter, SPM01 allows a live cable carrying up to 63A current to pass through. The sensor powers itself and measures voltage via the cable/terminal plate for L and the cable for N.

02: Platform 2 (3P+N, smart metering up to 63A)

Although SPM02 is designed for real-time electrical monitoring in three-phase electrical systems, it can also be used for 1P+N and 2P+N applications with the unbalanced-load alarm function switched off. SPM02 use the same ultra-thin CT as SPM01, which allows live cables carrying up to 63A current to pass through the 9.8mm diameter holes.


2.SPMXX-XXXX: Installation Scheme

The second “X” in the SPM naming sequence corresponds to the installation scheme. When selecting an SPM product, you are presented with two installation scheme choices, which are “upstream” and “downstream”, indicating the placement of the electricity meter in relation to the protective or control device.

U: Upstream

For the upstream SPM model, the smart energy meter is positioned on the source side of a protection or control device. Common examples of such devices include Miniature Circuit Breakers (MCB), Residual Current Circuit Breaker (RCCB), Arc Fault Detection Device (AFDD) and contactors.

Upstream Installation spm

Upstream Installation

D: Downstream

For the downstream SPM model, the energy meter is installed at the load side of the protective device (not allowed to be installed downstream of the control device due to possible product damage). A downstream model with flexible voltage measurement cable or cables can also function when it’s installed on the source side of a protection or control device by rotating the SPM 180 degrees. However, this could make operating the sensor inconvenient.

Downstream Installation spm

Downstream Installation

Whether to choose an upstream or a downstream model depends on the site situation. For example, if a bus bar is installed in the power distribution board, installing the SPM on the opposite side of the phase busbar is more convenient.


3. SPMXX-XXXX: Mounting Type

The following “X” in the naming sequence indicates the SPM’s mounting type, which can be flexible installation, MCB mounting and Din-rail mounting

1: MCB mounting

The MCB mounting type is typically equipped with terminal plates for the L connection and a soft silicon cable for the N connection (future platforms with terminal plates for both L and N connections also use “1”), enabling firm attachment to the MCB. This also ensures a tidy and organized appearance inside the distribution box. This model easily fits with most MCB lines from Siemens, Hager, ABB, Eaton, Legrand, and more.

MCB mounting

MCB mounting

MCB Mounting

2: Flexible installation

The flexible type features soft silicon cables for both L and N connections, allowing the SPM to hang conveniently within the power distribution box. This design proves advantageous in scenarios where space above or below Din-rails is constrained for operating wire connections.


4.SPMXX-XXXX: Communication Options

SPM boasts an array of wireless and wired communication options (indicated by the last “XX” in the naming sequence), ensuring optimal compatibility with diverse scenarios and catering to a range of specific needs.


TW: Tuya Wifi (Integrated to Tuya Smart cloud)

For those who find comfort in storing their energy usage data on the Tuya Cloud platform, SPM models with Tuya Cloud integration (Tuya CB2S module inside the sensor) would be the recommended choice. Users can effortlessly harness more data through Smart Life and Smart Industry, with both App and PC interfaces available for access.


EW: ESP32 Wifi (Integrated to customer-specific cloud)

For customer-specific cloud integration, our recommended offer is a product variant using the ESP32-C3 Wifi module. Customers can program the ESP32-C3 module on their own – read metering data via the UART port of the sensor MCU with Modbus protocol and further transmit the data to their own Mqtt server.


TZ: Tuya Zigbee (Integrated to Tuya Zigbee Gateway)

Another wireless communication option we offer is Zigbee, which is highly suitable for both households and small businesses. When compared to Wi-Fi communication, Zigbee signals are known for their increased stability.

SPM models with Tuya Zigbee Gateway integration use the private Zigbee 3.0 clusters/attributes maintained by Tuya Smart. With the energy monitoring dashboard at Smart Life APP, it provides a good experience of “open and play” requiring little IoT knowledge.


UZ: Universal Zigbee (Integrated to universal Zigbee coordinator)

SPM models with universal Zigbee Gateway integration use the standard Zigbee 3.0 clusters/attributes for energy meters. They fit perfectly for the professionals requesting the maximum level of flexibility for data reporting, storage and analysis.


M1: Modbus RTU (RS485 port supporting Modbus RTU protocol)

Modbus is a common implementation where the Modbus protocol is utilized for communication between devices over an RS485 network. This combination is widely used in industrial automation and control systems for reliable and efficient data exchange.

Our Modbus SPM model features a design optimized for local data transmission through twisted-pair cables, ensuring data privacy with local data access – a feature valued by privacy-conscious users. The configuration of the Modbus SPM models is as easy as configuring a Modbus energy meter.

Related Products

SPM01 (1P+N, 63A)

SPM02 (3P+N, 63A)


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