Peacefair PZEM-004T AC Multi-function Electric Energy Metering Power Monitor Module

The Peacefair PZEM-004T is a high-precision single-phase AC multi-function energy metering module designed for measuring AC voltage, current, active power, frequency, power factor, and active energy in real-time. Available in 10A (built-in shunt) and 100A (external CT) variants, this compact module communicates via a TTL UART serial interface using the Modbus-RTU protocol, making it ideal for integration with Arduino, ESP32, Raspberry Pi, and other microcontroller platforms. With 0.5% measurement accuracy, software-resettable energy accumulation, and an over-power alarm function, it is the go-to solution for IoT-based smart energy meters, home automation, industrial load monitoring, and power analysis applications.

Key Features

• Measures 6 AC electrical parameters: Voltage, Current, Active Power, Frequency, Power Factor, and Active Energy
• Two current variants: 10A (built-in shunt) and 100A (external CT clamp)
• High measurement accuracy: 0.5% for voltage, current, power, energy, and frequency
• TTL UART serial communication with Modbus-RTU protocol
• Fixed baud rate: 9600, 8 data bits, 1 stop bit, no parity
• Software-resettable active energy counter (0–9999.99 kWh)
• Programmable over-power alarm with threshold setting
• Non-invasive current measurement via split-core CT (100A version)
• Compact bare PCB design for embedded integration
• Wide operating temperature range: -20℃ to +60℃
• Compatible with Arduino, ESP32, Raspberry Pi, and NodeMCU

Technical Specifications

Applications

• IoT-based smart energy meters and home automation
• Residential and commercial power consumption monitoring
• Industrial load monitoring and equipment diagnostics
• Solar inverter output measurement and PV system monitoring
• EV charging station power tracking
• Distribution panel and sub-circuit energy tracking
• Arduino, ESP32, Raspberry Pi, and NodeMCU projects
• Energy auditing and power quality analysis
• Smart grid and utility-scale monitoring systems

Important Notes

• High voltage AC safety warning: This module measures mains AC voltage (80–260V). Ensure proper insulation, use appropriate enclosures, and follow local electrical codes. Disconnect power before wiring.
• TTL interface is passive: The module requires an external 5V DC supply on the VCC pin for communication. All four pins (5V, RX, TX, GND) must be connected for proper operation.
• UART cross-connection: Connect module RX to microcontroller TX, and module TX to microcontroller RX.
• 3.3V microcontroller caution: If using a 3.3V MCU (ESP32, Raspberry Pi), use a level shifter or voltage divider on the RX line, or verify your module supports 3.3V logic.
• CT clamp polarity: For the 100A version, ensure the CT clamp is closed properly around the live wire only, with correct polarity for accurate current direction.
• Do not connect AC ground to DC ground: Maintain galvanic isolation between the high-voltage AC side and low-voltage DC logic side.
• Calibration: Factory calibration is pre-applied. Recalibration (using 0xF8 address and password 0x3721) should only be performed by qualified personnel.
• Energy reset: Use the Modbus 0x42 function code to reset the accumulated energy counter via software.
• Store in anti-static packaging when not in use.