# AC energy measurement module, PZEM-004T-100A, v3.0, 100A, TTL, 80–260V

- Page: https://sigmanortec.ro/en/ac-energy-measurement-module-pzem-004t-100a-v30-100a-ttl-80260v
- Price: 84.91 RON
- Availability: In stock; 1-2 zile
- Reference: 88277 · EAN: 5949068078659
- Category: Mechatronics and IoT > Sensors and Modules > Voltage and Current Sensors
- Specifications: Nominal Current: 100 A; Input Voltage: 80 - 260 V; Input Voltage Type: AC; Model: PZEM-004T-100A v3.0; Communication interface: TTL
- Package (shipping data): 0.088 kg
- Updated: 2026-09-18
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 03:48 (Europe/Bucharest)

## Description

The module for monitoring consumption on single-phase AC networks, ideal for automation and IoT projects, measures voltage 80-260VAC, current 0-100A with an external transformer, power, frequency, power factor, and energy up to 9999.99kWh, communicates Modbus-RTU via UART TTL 9600, and provides optocoupled isolation for safe integration with Arduino, ESP32, or PC.
The PZEM-004T-100A module is a multifunction meter for single-phase AC networks, designed for accurate monitoring of the electrical energy consumption of an installation or an individual device. It measures voltage, current, active power, power factor, frequency, and consumed active energy simultaneously. The data is read by a microcontroller or a computer through the TTL serial interface. The module has no built-in display and is intended for integration into monitoring systems, automation, and IoT projects.
Voltage is measured directly on the mains, in the 80 - 260VAC range, with a resolution of 0.1V. Current is measured using an external current transformer, in the 0 - 100A range, with a resolution of 0.001A and a minimum measurement threshold of 0.02A. Active power is calculated up to 23kW, with a resolution of 0.1W and a minimum measurement threshold of 0.4W. Consumed energy is counted up to 9999.99kWh, with a resolution of 1Wh, and the energy counter can be reset from software. Mains frequency is measured in the 45 - 65Hz range, with a resolution of 0.1Hz, and power factor between 0.00 and 1.00, with a resolution of 0.01. Accuracy is 0.5% for voltage, current, power, frequency, and energy, and 1% for power factor.
The module allows configuring an alarm threshold for active power. Exceeding the threshold is signaled through a status register that can be read by the controller. The measurement circuit is galvanically isolated from the TTL interface by optocouplers, which protects the connected development board.
Communication uses the Modbus-RTU protocol over the UART TTL interface, at 9600 baud, 8 data bits, 1 stop bit, and no parity (9600 8N1). For a single module, the default address 0xF8 is used. The Modbus address can be configured in the 0x01 - 0xF7 range, allowing up to 247 modules to be connected on the same serial bus. The module is compatible with Arduino Uno, Nano, and Mega, with ESP32 and ESP8266, and with USB-TTL adapters for direct reading on a PC. It can also be used with STM32, Raspberry Pi, or other UART-based platforms through a Modbus-RTU implementation. For quick integration, the dedicated PZEM004Tv30 library is available. The module is also supported by ESPHome and Home Assistant.
The TTL interface is passive. The 5V pin powers only the interface optocouplers, while the measurement circuit is powered from the 220VAC mains. For this reason, the module communicates only when connected to the mains and when all 4 wires of the TTL interface are connected. For boards with 3.3V logic (ESP32, ESP8266, STM32), a logic level converter or a resistor divider is recommended on the module’s TX line.
WARNING! The module connects directly to the 220VAC mains voltage, which can cause electric shock or death. Assembly and any intervention on the connections must be done only with the mains disconnected. Do not touch the board, terminals, or conductors while the module is energized. Use an insulated enclosure for the final assembly. If you do not have experience with electrical installations, contact a licensed electrician.
Specifications:
Model: PZEM-004T-100A (v3.0)
Type: Single-phase AC measuring module with communication interface
Measured voltage: 80 - 260VAC
Voltage resolution: 0.1V
Measured current: 0 - 100A (with external current transformer)
CT: Closed loop
Minimum measurement current: 0.02A
Current resolution: 0.001A
Active power: 0 - 23kW
Minimum measurement power: 0.4W
Power resolution: 0.1W
Power factor: 0.00 - 1.00
Power factor resolution: 0.01
Frequency: 45 - 65Hz
Frequency resolution: 0.1Hz
Active energy: 0 - 9999.99kWh
Energy resolution: 1Wh
Accuracy: 0.5% (voltage, current, power, frequency, energy)
Power factor accuracy: 1%
Power alarm: Configurable threshold
Protocol: Modbus-RTU
Interface: UART TTL, 9600 baud, 8N1
Default address: 0xF8 (single module)
Configurable addresses: 0x01 - 0xF7
TTL interface power supply: 5V (external, from the development board)
Isolation: Optocoupler between the measurement circuit and the TTL interface
Operating temperature: -20 ~ +40°C
Dimensions: 78 x 37 x 19mm
Layout:
Usage:
Disconnect the power supply before any assembly operation.
Connect the module’s L and N terminals to the phase and neutral of the mains.
Pass only the phase conductor through the current transformer. Do not pass phase and neutral together, because the currents cancel out and the module will indicate 0A.
Connect the transformer wires to the module’s CT input.
Connect the TTL interface to the development board as follows: 5V to 5V, GND to GND, module TX to board RX, and module RX to board TX. All 4 wires are mandatory.
For 3.3V logic boards, use a logic level converter on the module’s TX line.
Reconnect the mains. The module responds on the serial interface only if mains voltage is present between L and N.
Install the PZEM004Tv30 library in Arduino IDE and upload the test code.
Open Serial Monitor at 115200 baud to view the measured values.
If you get read errors and only the TX LED blinks, swap the RX and TX wires.
If the current value seems high compared to the load power, check the power factor. For loads with a low power factor, the relation P = U x I does not apply.
Pinout:
Pin
Function
5V
TTL interface optocoupler power supply (5 V from the board)
RX
Data reception – connect to the board’s TX
TX
Data transmission – connect to the board’s RX
GND
TTL interface ground
L
Mains phase 80–260 VAC
N
Mains neutral
CT
Current transformer input (2 wires)
Modbus registers (read with function 0x04):
Register
Description
Resolution
0x0000
Voltage
0.1 V
0x0001
Current (lower 16 bits)
0.001 A
0x0002
Current (upper 16 bits)
—
0x0003
Power (lower 16 bits)
0.1 W
0x0004
Power (upper 16 bits)
—
0x0005
Energy (lower 16 bits)
1 Wh
0x0006
Energy (upper 16 bits)
—
0x0007
Frequency
0.1 Hz
0x0008
Power factor
0.01
0x0009
Alarm status
0xFFFF – alarm; 0x0000 – normal
Dimension diagram:
Library link:
https://github.com/mandulaj/PZEM-004T-v30