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ZX-CA Tester for Distribution Network Capacitance Current Testing
Introduction
In modern power distribution systems, the neutral point is typically operated ungrounded. When a single-phase-to-ground fault occurs, the fault current is dominated by the system’s capacitive current, generated by line-to-ground capacitances. Excessive capacitive current can prevent arc self-extinction, leading to persistent faults, equipment damage, and potential outages.
Chinese power regulations mandate the installation of arc suppression coils when capacitive current exceeds 30A in 10kV systems or 10A in 35kV systems. Accurate measurement of capacitive current is therefore a critical prerequisite for proper system design and mitigation. The ZX-CA Automatic Capacitance Current Tester addresses this need with a practical, secondary-side testing solution.
Key Features of the ZX-CA Tester
The ZX-CA Tester is engineered to simplify and secure capacitive current measurement in live distribution networks, offering several key advantages:
Secondary-Side Testing Only: The tester connects directly to the voltage transformer (PT) secondary side, eliminating the need for primary-side access or line outages.
Safety and Efficiency: Testing carries no direct electrical hazards, requiring no complex safety measures or lengthy scheduling approvals.
Simple Connection: Users simply connect the measuring line to the PT’s open-delta terminals to begin data acquisition.
Non-Intrusive Test Signal: The injected inter-frequency test signal has no impact on relay protection systems or the PT itself, while avoiding 50Hz power frequency interference.
High Voltage Withstand Capability: The output terminals can withstand up to 100V AC. Even if a single-phase ground fault occurs during testing, the PT and tester remain undamaged.
Reliable Performance: The tester delivers accurate, stable, and repeatable results without requiring special safety precautions.
Technical Specifications
Parameter | Specification |
Ambient Temperature | -10°C ~ 50°C |
Environmental Humidity | ≤ 85% RH |
Working Power Supply | AC 220V ± 20% |
Power Frequency | 50 ± 5Hz |
Measuring Range (Capacitance) | 0.3 ~ 125 µF |
Measuring Range (Current) | 1 ~ 250 A |
Measurement Error | ≤ 5% |
Dimensions | 345mm × 295mm × 175mm |
Instrument Weight | 5 kg |
Conclusion
The ZX-CA Automatic Capacitance Current Tester provides a safe, efficient, and reliable method for measuring capacitive current in distribution networks. By leveraging secondary-side injection technology, it eliminates the risks and complexities associated with traditional primary-side testing, making it an essential tool for power system technicians to comply with regulations, select appropriate arc suppression equipment, and ensure the stability of distribution networks.
GDZX is a manufacturer of power detection equipment, offering a diverse range of products with comprehensive models and providing professional technical support. Contact us at +86-27-6552607 or +86-17396104357.Website: http://en.gdzxdl.com/
