LJ-ZW20-10(12) Zero Sequence Current/Electronic Transformer
Product Functions
This transformer's core function is to accurately sense and transform zero-sequence current for ground-fault protection within power systems. It monitors the vector sum of three-phase currents to detect imbalances caused by ground faults, enabling rapid circuit breaker tripping to prevent equipment damage and enhance safety. Specifically engineered for ZW20 vacuum circuit breakers, it provides integrated protection for all three phases and the neutral path. Its design allows it to function as a combined primary and secondary fusion transformer, simplifying installation and providing reliable signal isolation for downstream protection relays and metering devices.
Applicable Environment
The LJ-ZW20-10(12) is engineered for use in indoor or weather-protected switchgear cabinets housing ZW20 series vacuum circuit breakers. It is ideally suited for 10kV or 12kV medium-voltage power distribution networks, commonly found in industrial plants, commercial complexes, transformer substations, and ring main units. Its application is focused on enclosed electrical environments where it is protected from direct exposure to severe weather, excessive dust, and condensation, ensuring stable operation within controlled temperature and humidity ranges typical of indoor electrical equipment installations.
Product Highlights
◆Dedicated System Integration: Specifically designed for seamless compatibility and optimal performance with ZW20 vacuum circuit breakers, providing a complete and reliable protection solution.
◆Dual Protection Role: Delivers comprehensive protection by monitoring both three-phase currents and zero-sequence current for accurate ground-fault detection and system imbalance monitoring.
◆Flexible Configuration & Customization: Offers versatile standard rated current ratios from 20/1A to 600/5A and welcomes custom specifications, including high-precision models, to meet precise project requirements.
◆Compact Fused Design: Incorporates a primary-secondary fusion structure, saving space within switchgear and simplifying system architecture by combining measurement and isolation functions.
◆High Insulation & Reliability: Features robust insulation (≥23kV between secondary and ground), ensuring long-term operational safety, signal integrity, and protection against transient overvoltages in medium-voltage applications.