How to Use CT PZEM-004T 100A: Examples, Pinouts, and Specs

The CT PZEM-004T 100A is a multifunctional energy meter designed for AC systems. It is capable of measuring key electrical parameters such as voltage, current, power, energy, and frequency. With a maximum current handling capacity of 100A, this device is ideal for monitoring and managing electrical consumption in residential, commercial, and industrial applications. Its compact design and real-time data output make it a popular choice for energy monitoring systems.

• Home energy monitoring systems
• Industrial equipment power usage tracking
• Renewable energy systems (e.g., solar inverters)
• Smart home automation projects
• Electrical load analysis and optimization

Below are the key technical details of the CT PZEM-004T 100A:

The CT PZEM-004T 100A has a 4-pin interface for communication and power. Below is the pin configuration:

1. Power Supply: Connect the VCC pin to a 5V DC power source and the GND pin to ground.
2. UART Communication: Connect the RX pin of the PZEM-004T to the TX pin of your microcontroller (e.g., Arduino UNO) and the TX pin of the PZEM-004T to the RX pin of the microcontroller.
3. Current Transformer (CT): Place the external CT around the live wire of the AC circuit you want to monitor. Ensure the CT is oriented correctly as indicated by the arrow on the CT housing.
4. Voltage Measurement: Connect the AC voltage input terminals of the PZEM-004T to the live and neutral wires of the AC circuit.

• Safety First: Always ensure the circuit is powered off before making connections to avoid electric shock.
• Isolation: Use proper electrical isolation techniques when working with high-voltage AC systems.
• Baud Rate: Ensure the microcontroller's UART baud rate is set to 9600 bps to communicate with the PZEM-004T.
• CT Placement: The CT should only enclose the live wire, not both live and neutral wires, to ensure accurate current measurement.

Below is an example Arduino sketch to read data from the CT PZEM-004T 100A using the SoftwareSerial library:

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial pzemSerial(10, 11); // RX = Pin 10, TX = Pin 11

// PZEM-004T communication commands
byte readCommand[] = {0xB0, 0xC0, 0xA8, 0x01, 0x01, 0x00, 0x1A};

// Buffer to store response
byte response[7];

void setup() {
  Serial.begin(9600);          // Initialize Serial Monitor
  pzemSerial.begin(9600);      // Initialize PZEM-004T communication
  Serial.println("PZEM-004T 100A Energy Meter");
}

void loop() {
  // Send read command to PZEM-004T
  pzemSerial.write(readCommand, sizeof(readCommand));
  delay(100); // Wait for response

  // Read response from PZEM-004T
  if (pzemSerial.available() >= 7) {
    for (int i = 0; i < 7; i++) {
      response[i] = pzemSerial.read();
    }

    // Extract voltage, current, and power from response
    float voltage = (response[2] << 8 | response[3]) / 10.0; // Voltage in volts
    float current = (response[4] << 8 | response[5]) / 100.0; // Current in amps
    float power = (response[6] << 8 | response[7]) / 10.0;    // Power in watts

    // Print values to Serial Monitor
    Serial.print("Voltage: ");
    Serial.print(voltage);
    Serial.println(" V");

    Serial.print("Current: ");
    Serial.print(current);
    Serial.println(" A");

    Serial.print("Power: ");
    Serial.print(power);
    Serial.println(" W");

    Serial.println("-----------------------");
  }

  delay(1000); // Wait 1 second before next reading
}

• Replace 10 and 11 in SoftwareSerial pzemSerial(10, 11) with the desired pins for RX and TX on your Arduino.
• Ensure the PZEM-004T is properly connected to the Arduino before uploading the code.
• The code assumes the PZEM-004T is configured with its default address. If the address has been changed, update the readCommand array accordingly.

1. No Data Received:

   • Ensure the RX and TX pins are correctly connected between the PZEM-004T and the microcontroller.
   • Verify the baud rate is set to 9600 bps.
   • Check the power supply to the PZEM-004T.

2. Incorrect Readings:

   • Ensure the CT is properly clamped around the live wire only.
   • Verify the AC voltage input connections are secure and correct.

3. Communication Errors:

   • Check for loose or damaged wires in the UART connection.
   • Ensure no other devices are interfering with the UART communication.

Q: Can the PZEM-004T measure DC voltage or current?
A: No, the PZEM-004T is designed specifically for AC systems and cannot measure DC parameters.

Q: How do I reset the energy reading to zero?
A: The energy reading can be reset by sending a specific command via UART. Refer to the PZEM-004T datasheet for the reset command.

Q: Can I use multiple PZEM-004T modules with one microcontroller?
A: Yes, you can use multiple modules by assigning unique addresses to each module and communicating with them sequentially.

Q: Is the PZEM-004T compatible with ESP8266 or ESP32?
A: Yes, the PZEM-004T can be used with ESP8266 or ESP32, but you may need to use hardware or software UART depending on your setup.