ZW32-40.5/1250A built-in sensor integrated primary and secondary high-voltage vacuum circuit breaker

The ZW32-40.5 built-in sensor is an integrated electronic current-voltage sensing unit, which adopts LPCT low-power coil current measurement and capacitive voltage division voltage measurement technologies, and can directly output analog quantities for FTU to perform protection and metering without external CT/PT.

Core Parameters and Technical Principles

Current sensor: Based on the LPCT (low-power coil) principle, the transformation ratio range is usually 30A–1250A/1A (supports wide-range self-adaptation), the accuracy meets the 0.5S level metering and protection requirements, and it has good linearity and anti-saturation characteristics.

Voltage sensor: Adopts capacitive voltage division technology, directly collects phase voltage and zero-sequence voltage, does not require an independent electromagnetic PT, and supports overvoltage, undervoltage and single-phase ground fault criterion extraction.

Integration method: The sensor and the vacuum interrupter are jointly packaged in a solid-sealed pole or integrated inside the body, realizing "deep integration of primary and secondary systems", eliminating external wiring errors and safety hazards.

Output signal: Directly outputs small-signal analog quantities (mA level/mV level) to the built-in FTU terminal, supporting fault recording and three-remote (telemetry, tele-signaling) functions.

Functional Features and Application Advantages

No external equipment required: The built-in design eliminates the need for external current transformers (CT) and voltage transformers (PT) required for traditional outdoor pole-mounted switches, significantly reducing the volume and weight (about 2/3 of traditional products).

High-precision protection: Supports zero-sequence power direction protection, the zero-sequence current sensitivity can reach 0.1A, which can identify single-phase ground faults and cooperate with the automatic reclosing logic.

Environmental adaptability: Fully sealed structure is moisture-proof and pollution-proof, the working temperature range is usually -40℃～+70℃, adapting to high altitude (≤5500 meters) and harsh climate environments.

Standardized interface: Complies with the national grid primary and secondary integrated complete equipment standards, with complete analog quantities, which can be directly connected to the distribution automation master station system for fault judgment.

Note: The specific transformation ratio (such as 630A or 1250A specifications) and accuracy level shall refer to the nameplate of the specific ordered model, and the detailed parameters of different manufacturers may be slightly adjusted.