SPM Series

SPM Series — Miniature Energy Meters

Ultra-compact miniature energy meters with built-in CTs, designed to install directly above or below circuit breakers in final distribution boards — no DIN rail space required.

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Product Variants

SPM products are defined across three dimensions:

1. Product Platform

	SPM01	SPM02
Phase	Single-phase (1PN)	Three-phase (3PN)
Rated Voltage	220–240 VAC (L-N)	220–240 VAC (L-N) / 380–415 VAC (L-L)
Max Current	63 A	63 A
Dimension	46.8 × 17.8 × 21.3 mm (1MW)	46.4 × 53.0 × 21.3 mm (3MW)
Accuracy	±1% (active energy, resistive load)	±1% (active energy, resistive load)

2. Installation Style

	FLEX	MCBM
How it mounts	Via voltage take-off wires — flexible positioning	Clips directly onto MCB body
Breaker compatibility	Universal — all circuit breakers	Verified with Siemens 5SY/5SL only
Mounting direction	N/A	Top-mounted (U1) or Bottom-mounted (D1) — to match your breaker's wiring direction
Best for	Retrofit projects, mixed or unknown breaker brands	New installations with Siemens 5SY/5SL

💡 If unsure about MCB compatibility, always choose FLEX.

3. Connectivity

Variant	Communication	Architecture	API Style	Typical Users
Tuya Wi-Fi (*TW)	Wi-Fi	BK7231N SoC (Tuya Firmware, Slave) + Metering MCU (Bituo Firmware, Master)	MQTT(Tuya Proprietary)	Tuya ecosystem, IoT beginners
Tuya Zigbee (*TZ)	Zigbee	EFR32MG21 SoC (Tuya Firmware, Slave) + Metering MCU (Bituo Firmware, Master)	Tuya Proprietary Clusters	Tuya ecosystem with Zigbee hub
Open Wi-Fi (*EW)	BLE + Wi-Fi	ESP8685 SoC (Bituo Firmware, Master) + Metering MCU (Bituo Firmware, Slave)	MQTT, HTTP, UDP, BLE	DIYers, System Integrators
Std. Zigbee (*TZ-U01)	Zigbee 3.0	EFR32MG21 SoC (Bituo Firmware, Master) + Metering MCU (Bituo Firmware, Slave)	Standard Zigbee 3.0 Clusters	System Integrators, DIYers

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Sub Pages

Model	Description
SPM01 FLEX	1PN 63A Wireless Communication— Flexible-Installation
SPM01 MCBM	1PN 63A Wireless Communication— MCB-Mounting
SPM02 FLEX	3PN 63A Wireless Communication— Flexible-Installation
SPM02 MCBM	3PN 63A Wireless Communication— MCB-Mounting
SPM01R FLEX	1PN 63A Wired Communication— Flexible-Installation
SPM01R MCBM	1PN 63A Wired Communication— MCB-Mounting
SPM02R FLEX	3PN 63A Wired Communication— Flexible-Installation
SPM02R MCBM	3PN 63A Wired Communication— MCB-Mounting

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Related

SPM/SDM Zigbee Cluster Reference

Modbus TCP Map - ESP32-8685