Fully Enclosed High Tension Current Transformers 200/5 250/5 Protection IEC

The LZZBJ9-10 is an indoor, post-type, fully enclosed current transformer (CT) designed for power systems with a rated frequency of 50Hz or 60Hz and a maximum equipment voltage of 12kV. It is the primary choice for indoor switchgear (such as the KYN28A-12) to provide signals for current measurement, energy metering, and relay protection.

Constructed using advanced vacuum-cast epoxy resin, the LZZBJ9-10 features a reinforced insulation structure that protects against moisture, pollution, and mechanical stress. Its rugged "post-type" design also allows it to serve as a supporting insulator for the main busbar, optimizing space within the switchgear cabinet.

• Superior Measurement Accuracy: Available in high-precision classes (Class 0.2, 0.2S, or 0.5), making it suitable for revenue-grade billing and high-sensitivity monitoring.

• Reliable Relay Protection: Offered with 10P10 or 10P20 protection classes, ensuring the CT maintains accuracy during massive overcurrent events to trigger protective relays instantly.

• High Short-Circuit Strength: Engineered to withstand significant thermal and dynamic stress during grid faults, preventing catastrophic failure of the metering circuit.

• Partial Discharge Excellence: Our vacuum-casting process ensures a void-free epoxy block, resulting in extremely low partial discharge (PD) levels. This significantly extends the service life beyond industry standards.

• Maintenance-Free Durability: The fully enclosed design is resistant to atmospheric aging and chemical corrosion, requiring only simple external cleaning during routine inspections.

1. Medium Voltage Switchgear: The standard current sensing component for KYN28, XGN, and other 10kV–12kV metal-clad cabinets.

2. Industrial Substations: Reliable current monitoring for heavy manufacturing plants, mining operations, and data centers.

3. Revenue Metering: Providing high-accuracy current reference for commercial billing meters in utility-to-industrial junctions.

4. Power Quality Analysis: Sensing harmonics and current fluctuations for advanced power monitoring systems.

• Copper Core Excellence: We use 99.9% oxygen-free copper for all windings, ensuring minimal resistance and maximum thermal efficiency.

• Custom Ratios & Multi-Ratios: We provide bespoke primary/secondary ratios (e.g., 200/5, 400/5, 1000/5) and multi-ratio CTs to meet specific project load requirements.

• Rigorous FAT Testing: Every unit undergoes a Factory Acceptance Test (FAT), including polarity checks, error testing, and power-frequency voltage withstand testing.

• Tropicalized Design: Our epoxy formula is stabilized for use in high-humidity and high-temperature environments, ensuring dielectric strength remains stable over decades.

Q: Can I use this CT for both metering and protection simultaneously?

A: Yes. The LZZBJ9-10 can be configured with multiple secondary cores (e.g., one for measurement and one for protection) within the same epoxy body.

Q: What is the difference between Class 0.2 and 0.2S?

A: Class 0.2S is a "Special" accuracy class that maintains its precision even at very low loads (as low as 1% of rated current), whereas standard Class 0.2 is rated for loads between 20% and 120%.

Q: How do I select the right Burden (VA)?

A: Calculate the total resistance of your secondary circuit, including cables and the internal impedance of the meters/relays. Selecting a CT with a slightly higher VA rating than your total load ensures the CT remains within its accuracy class.