How to Use CT PZEM004T: Examples, Pinouts, and Specs

The CT PZEM004T is a multifunctional energy meter designed to measure key electrical parameters such as voltage, current, power, energy, and frequency. It is commonly used in conjunction with current transformers (CTs) to monitor AC electrical systems. This component is ideal for applications requiring real-time energy monitoring, such as home automation, industrial energy management, and renewable energy systems.

• Home energy monitoring systems
• Industrial power consumption analysis
• Renewable energy systems (e.g., solar, wind)
• Smart grid and IoT-based energy management
• Electrical equipment testing and diagnostics

The CT PZEM004T is a versatile and compact module with the following key specifications:

The CT PZEM004T module has a 4-pin interface for communication and power connections. Below is the pinout:

Additionally, the module includes terminals for connecting the AC voltage input and the current transformer (CT).

1. Connect the AC Voltage Input:

   • Connect the live and neutral wires of the AC system to the voltage input terminals of the module.
   • Ensure proper insulation and safety precautions when working with high-voltage AC systems.

2. Connect the Current Transformer (CT):

   • Attach the CT to the AC line you want to monitor.
   • Connect the CT's output wires to the CT input terminals on the module.

3. Connect to a Microcontroller:

   • Use the UART interface to connect the module to a microcontroller (e.g., Arduino UNO).
   • Connect the module's TX pin to the microcontroller's RX pin and the RX pin to the microcontroller's TX pin.
   • Provide a 5V DC power supply to the VCC pin and connect the GND pin to the microcontroller's ground.

4. Install the Required Library:

   • For Arduino, use the "PZEM004T" library available in the Arduino Library Manager.

5. Upload the Code:

   • Use the example code below to read data from the module.

#include <PZEM004T.h> // Include the PZEM004T library

// Define the RX and TX pins for the PZEM004T module
#define RX_PIN 10
#define TX_PIN 11

// Create a PZEM004T object
PZEM004T pzem(RX_PIN, TX_PIN);

void setup() {
  Serial.begin(9600); // Initialize serial communication for debugging
  Serial.println("PZEM004T Energy Meter Example");
}

void loop() {
  // Read voltage
  float voltage = pzem.voltage();
  if (voltage < 0) {
    Serial.println("Error reading voltage!");
  } else {
    Serial.print("Voltage: ");
    Serial.print(voltage);
    Serial.println(" V");
  }

  // Read current
  float current = pzem.current();
  if (current < 0) {
    Serial.println("Error reading current!");
  } else {
    Serial.print("Current: ");
    Serial.print(current);
    Serial.println(" A");
  }

  // Read power
  float power = pzem.power();
  if (power < 0) {
    Serial.println("Error reading power!");
  } else {
    Serial.print("Power: ");
    Serial.print(power);
    Serial.println(" W");
  }

  // Read energy
  float energy = pzem.energy();
  if (energy < 0) {
    Serial.println("Error reading energy!");
  } else {
    Serial.print("Energy: ");
    Serial.print(energy);
    Serial.println(" kWh");
  }

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

• Safety First: Always ensure proper insulation and safety measures when working with high-voltage AC systems.
• CT Orientation: Ensure the current transformer (CT) is installed in the correct orientation for accurate readings.
• Communication Distance: The UART communication distance should not exceed 10 meters for reliable data transmission.
• Power Supply: The module is self-powered from the AC voltage input, but the UART interface requires a 5V DC supply.

1. No Data Output:

   • Ensure the UART connections (TX and RX) are correctly wired.
   • Verify that the baud rate is set to 9600 in the microcontroller code.

2. Incorrect Readings:

   • Check the CT installation and ensure it is properly clamped around the AC line.
   • Verify that the AC voltage input is securely connected.

3. Module Not Powering On:

   • Ensure the AC voltage input is within the specified range (80V - 260V AC).
   • Check for loose or faulty connections.

4. Communication Errors:

   • Ensure the microcontroller and module share a common ground.
   • Verify that the RX and TX pins are not swapped.

Q: Can the CT PZEM004T measure DC systems?
A: No, the module is designed specifically for AC systems and cannot measure DC voltage or current.

Q: What is the maximum current the module can measure?
A: The module can measure up to 100A when used with the appropriate current transformer (CT).

Q: Can I use multiple PZEM004T modules with a single microcontroller?
A: Yes, you can use multiple modules by assigning unique addresses to each module via the UART interface.

Q: Is the module compatible with 3.3V microcontrollers?
A: The module requires a 5V DC supply for UART communication. Use a level shifter if connecting to a 3.3V microcontroller.

By following this documentation, you can effectively integrate the CT PZEM004T into your energy monitoring projects.