1. Product Overview
The YHDC SCT019 is a split core current transformer designed for measuring AC current. Its split core design allows for non-invasive installation, making it suitable for existing electrical installations without the need to disconnect wires. This model features an 80A rated input and a 0.333V rated output, providing a safe and accurate method for current monitoring.
Key Features:
- Split Core Design: Easy installation without circuit interruption.
- Opening Size: 19mm x 19mm, accommodating various cable sizes.
- High Accuracy: ± 0.5% for reliable measurements.
- Wide Operating Temperature: Suitable for diverse environments.
2. Safety Information
Please read and understand all safety instructions before installing or operating the SCT019 current transformer. Failure to follow these instructions may result in electrical shock, fire, or damage to the device.
- Qualified Personnel: Installation and maintenance should only be performed by qualified electrical personnel.
- De-energize Circuit: Always ensure the circuit to be measured is de-energized before opening or closing the transformer core.
- Voltage Rating: Do not exceed the maximum rated voltage of 660V.
- Insulation: Ensure proper insulation of all connections.
- Environmental Conditions: Do not expose the device to moisture, extreme temperatures outside its operating range, or corrosive environments.
3. Technical Specifications
| Parameter | Value |
|---|---|
| Model | SCT019 |
| Opening Size | 19mm x 19mm |
| Material of Core | Permalloy |
| Flame Resistance | UL94-V0 |
| Voltage Rating | 660V |
| Rated Input Current | 80A |
| Rated Output Voltage | 0.333V |
| Accuracy | ± 0.5 % |
| Working Temperature | -25 ℃ ~ + 70 ℃ |
| Storage Temperature | -40 ℃ ~ + 85 ℃ |
| Frequency Range | 20 Hz ~ 1KHz |
| Dielectric Strength | 3.5KV 50Hz 1min |
| Max Sampling Resistance | 20Ω |
| Weight | 91g |
| Product Dimensions | 2 x 0.61 x 2.1 inches |
4. Installation and Setup
The SCT019 current transformer is designed for easy installation on existing conductors. Follow these steps for proper setup:
- Prepare the Circuit: Ensure the electrical circuit where the current is to be measured is completely de-energized and locked out according to safety procedures.
- Open the Core: Gently press the latch mechanism on the side of the transformer to open the split core. Refer to the diagram below for the opening and closing method.
- Position the Conductor: Place the conductor (wire carrying the current to be measured) through the opening of the transformer core. Ensure the conductor passes through the center of the opening for optimal accuracy.
- Close the Core: Close the split core firmly until the latch mechanism clicks into place, ensuring a secure and complete closure. A proper closure is critical for accurate readings.
- Connect Output Wires: Connect the output wires of the transformer to your measuring device (e.g., multimeter, data logger, energy meter) that is designed to accept a 0.333V AC input. The white wire is typically the positive output, and the black wire is the common/negative.
- Verify Connections: Double-check all connections for security and correct polarity.
- Re-energize Circuit: Once all connections are secure and verified, the circuit can be safely re-energized.

Image: SCT019 Series Specification Sheet. This diagram illustrates the opening/closing method, dimensions, and a schematic diagram for the SCT019 series. Note: The specific current ratings (e.g., 0-30A) shown in this image are for a different variant within the SCT019 series. Please refer to the Technical Specifications section for the 80A/0.333V model's exact ratings.
5. Operation
Once installed, the SCT019 current transformer will convert the AC current flowing through the primary conductor into a proportional AC voltage signal (0.333V at rated input). This voltage signal can then be read by a compatible measuring device.
- Measurement Range: The transformer is designed for a rated input of 80A. Measurements outside this range may affect accuracy.
- Frequency: The device operates accurately within a frequency range of 20 Hz to 1 KHz.
- Output Interpretation: The 0.333V output corresponds to the 80A input. Your measuring device should be calibrated to interpret this voltage proportionally to the current. For example, if the measuring device reads 0.1665V, the current would be 40A (half of the rated 80A).
6. Maintenance
The YHDC SCT019 current transformer is designed for long-term, maintenance-free operation. However, periodic checks are recommended:
- Visual Inspection: Periodically inspect the transformer for any signs of physical damage, cracks, or discoloration.
- Connection Integrity: Ensure all electrical connections remain tight and free from corrosion.
- Core Closure: Verify that the split core remains securely closed. A loose core can lead to inaccurate readings.
- Cleaning: If necessary, gently clean the exterior of the transformer with a dry, soft cloth. Do not use solvents or abrasive cleaners.
7. Troubleshooting
If you encounter issues with your SCT019 current transformer, consider the following:
- No Output/Incorrect Reading:
- Check Core Closure: Ensure the split core is fully closed and latched.
- Verify Connections: Confirm that the output wires are correctly connected to the measuring device and that the device is powered on and configured correctly.
- Conductor Placement: Ensure the primary conductor passes through the center of the transformer opening.
- Circuit Current: Verify that there is actual AC current flowing through the primary conductor.
- Measuring Device: Test your measuring device with a known voltage source to ensure it is functioning correctly.
- Inconsistent Readings:
- External Interference: Check for strong magnetic fields or electrical noise sources near the transformer.
- Loose Connections: Re-tighten all connections.
- Core Integrity: Inspect the core for any damage or foreign objects preventing complete closure.
8. Warranty and Support
Information regarding specific warranty terms and customer support for the YHDC SCT019 current transformer is not available in this manual. Please refer to your purchase documentation or contact your supplier for details on warranty coverage and technical assistance.





