The SCT-013-000 is the industry-standard "split-core" current transformer (CT) used for measuring AC current without needing to disconnect any wiring. Its clip-on design makes it exceptionally popular for home energy monitoring, DIY smart meters, and industrial load sensing. Because it is a non-invasive sensor, it provides a safe way to monitor high-voltage mains power.

Specifications

• Model: SCT-013-000
• Rated Input Current: 0A – 100A AC
• Output Type: 0 – 50mA Current (1:2000 Turns Ratio)
• Non-linearity: +/- 3% (at 10%–120% rated input current)
• Opening Size: 13mm x 13mm (Fits standard household mains cables)
• Dielectric Strength: 6000V AC/1min
• Operating Temperature: -25C to +70C
• Flame Resistance: UL94-V0
• Cable Length: 1 meter (terminated with a standard 3.5mm mono jack)

Features

• Split-Core Design: The sensor "snaps" open, allowing you to clip it around a single wire (Live or Neutral) without interrupting the power supply.
• High Safety Rating: Features 6000V dielectric strength, ensuring complete electrical isolation between the mains wire and your microcontroller.
• Standard Connector: Uses a 3.5mm audio-style jack for easy connection to sensor shields or custom breakout boards.
• Durable Build: Rated for over 1,000 opening and closing cycles, with a rugged ferrite core and flame-retardant housing.
• Open Energy Monitor Compatible: This is the primary sensor used by the OpenEnergyMonitor project, benefiting from extensive library support and community documentation.

Pin & Wiring Configuration

• Connection: The 3.5mm jack typically provides the two secondary coil outputs.
• Burden Resistor Required: This specific model (SCT-013-000) outputs a current signal. To read it with a microcontroller, you must add an external burden resistor across the output to convert the current to voltage.
  • Note: If your model is a "voltage output" version (e.g., SCT-013-030), the resistor is already built-in.

Common Applications

• Whole-House Energy Monitoring: Clipping onto the main incoming phase of a distribution board to track total power usage.
• Appliance Power Tracking: Monitoring high-draw devices like air compressors, water heaters, or AC motors.
• Solar PV Export Monitoring: Measuring the current being fed back into the grid from a solar inverter.
• Overload Protection: Sensing fault currents in industrial machinery to trigger safety shut-offs.

Usage Tips

• Single Wire Only: You must clip the sensor around either the Live or Neutral wire. If you clip it around a whole power cord (containing both wires), the magnetic fields will cancel out, and you will get a reading of zero.
• Burden Resistor Selection: A common choice for a 5V Arduino is a 22 Ohm to 33 Ohm resistor. This scales the 100A/50mA signal to a voltage range the ADC can handle.
• Directionality: While it measures AC, the physical orientation (the "K-L" markings on the sensor) can help maintain phase consistency if you are measuring real power (Watts) alongside a voltage sensor.