FZW28‑12 Outdoor AC High‑Voltage Sectionalizer (Recloser) Vacuum Load Switch

Overview

FZW28‑12 Outdoor High‑Voltage AC Sectionalizer Vacuum Load Switch (commonly known as “watchdog”) is outdoor distribution equipment with rated voltage 12 kV, three‑phase AC 50 Hz. It consists of three main parts: switch main body, FDR‑01 fault‑detection controller and voltage transformer. It adopts vacuum arc‑extinguishing and SF₆ gas as insulating medium, which is an excellent option among pole‑mounted load switches.

Designed for pole‑mounted applications on 10 kV feeder lines. When a fault occurs on a T‑connected user branch or inside the user facility, it may cause power outages on main feeders and other adjacent users. Installing this user‑side sectionalizing load switch at the T‑connection point (responsibility boundary point) is an ideal solution to avoid such cascading failures.

Standards Compliance

• GB 3804 《3.6 kV‑40.5 kV High‑Voltage AC Load Switches》
• GB/T 11022 《Common Technical Requirements for High‑Voltage Switchgear and Controlgear Standards》
• DL/T 593 《Common Technical Specification for Ordering of High‑Voltage Switchgear and Controlgear》

Product Features

‑ Automatically cut off single‑phase earth fault When single‑phase earth fault occurs on user branch line, the sectionalizer opens automatically without affecting substation and other branch users on the feeder. A through‑type zero‑sequence current transformer with ratio 20/1, cast with epoxy resin, is built‑in for earth‑fault current detection.

‑ Automatically isolate phase‑to‑phase short‑circuit fault Upon phase‑to‑phase short‑circuit fault on user branch, the sectionalizer opens immediately after tripping of substation outlet protection. After substation re‑closing, the faulty line is isolated automatically, and power supply for other branch users on feeder is restored rapidly. Two through‑type protective current transformers (ratio 600/1 or as specified by customer) are installed inside to detect short‑circuit fault current.

‑ Fast fault‑location capability After sectionalizer protection trips due to user‑branch failure, only the responsible user loses power. Fault information will be reported actively. If communication module is equipped, fault data can be automatically uploaded to power management center.

‑ User load monitoring Wired or wireless communication accessories are optional for sectionalizer. Monitoring data can be transmitted to power management center to realize remote real‑time monitoring of user load.

‑ Capable of ring‑network operation, applicable for ring‑main circuits.

‑ Metering function: capable of measuring line voltage, current, frequency and electric energy; data can be remotely transmitted to management center.

‑ Harmonic‑analysis function, providing reliable reference for future power‑grid pollution treatment.

‑ Diverse controller configurations: Supports conventional operation and protection. Optional GSM / GPRS module enables SMS control and remote PC control & protection. Local handheld terminal is also available for switch control, parameter modification and status checking.

‑ Reliable sealing performance: Adopts proven sealed‑enclosure design with IP67 protection class. Housing is manufactured by one‑step deep‑drawing moulding process, featuring easy sealing, high gas‑tightness and high mechanical strength.

‑ Maintenance‑free performance: Main circuit, secondary components and operating mechanism of the switch are fully sealed in SF₆ gas (zero gauge pressure), immune to ambient conditions, delivering stable, reliable and maintenance‑free performance.

‑ Excellent cable‑entry & exit performance: Cable‑in‑and‑out connection is supported. Patented fluid‑silicone‑rubber angle bushing is optional with superior external insulation performance.

‑ Safe operation: Explosion‑proof device is fitted on top of enclosure, effectively preventing ejection of high‑temperature gas and debris under fault conditions.