ZW8-12 Vacuum Circuit Breaker

Table of Contents

The ZW8-12 Vacuum Circuit Breaker guide is a high-performance outdoor switchgear designed for AC 50Hz, 10–12kV three-phase power systems. As a key component in modern power distribution networks, it provides reliable load switching, overload protection, and short-circuit interruption. Engineered to operate efficiently in harsh outdoor environments, the vacuum circuit breaker is ideal for applications in power utilities, rural substations, industrial grids, and smart distribution systems.

Compliant with IEC 62271-100, the ZW8-12 series supports modular enhancements such as disconnector integration, surge protection, automatic reclosers, and power electronics PT modules for intelligent automation and remote control.

ZW8-12 outdoor vacuum circuit breaker mounted on pole in medium-voltage power system

Key Features of ZW8-12 Vacuum Circuit Breaker

  • Vacuum Interruption Technology: Provides fast, arc-free switching for load and fault currents.
  • Modular Upgrade Options: Compatible with surge arresters, isolators, reclosers, automation metering, and dual power switching devices.
  • Wide Operating Range: Can operate in extreme outdoor temperatures, up to 2000 meters altitude, with high wind and seismic resistance.
  • Intelligent Variants: Versions like ZW8-12/C, ZW8-12/PT, and ZW8-12/ePT offer smart fault detection, recloser functionality, and energy-autonomous operation.
  • Long Service Life: Rated for 10,000 mechanical operations and 50 short-circuit breaking cycles.
ZW8-12 vacuum circuit breaker with isolator and lightning arrester accessories

Application Scenarios

The ZW8-12 Vacuum Circuit Breaker is used across various utility and industrial sectors:

  • Rural and urban medium-voltage distribution networks
  • Pole-mounted outdoor breaker stations
  • Renewable energy and small hydropower grid connections
  • Smart grid automation and fault isolation
  • Substations and ring main units requiring recloser functionality

Technical Parameters of ZW8-12 Vacuum Circuit Breaker

ItemUnitParameter
Rated VoltagekV12
Power Frequency Withstand Voltage (1 min)kV42
Lightning Impulse Withstand Voltage (Peak)kV75
Rated FrequencyHz50 / 60
Rated CurrentA630 / 1250
Rated Short-Circuit Breaking CurrentkA20
Rated Short-Time Withstand Current (RMS)kA20
Rated Peak Withstand CurrentkA50
Rated Short-Circuit Closing CurrentkA50
Capacitor Bank Breaking Current (Single/Back-to-Back)A630 / 400
Short-Circuit Durations4
Short-Circuit Breaking TimesTimes50
Main Circuit ResistanceμΩ≤120 (≤200 with isolator)
Operating VoltageV DC220
Mechanical LifeTimes10,000
Overcurrent Setting RangeA1–10
Quick-Break Current RangeA6–20
Delay Time Rangems40–850
Remote Control Distancem>30
Reclose TimesTimes0–3
Operating SequenceO-0.3s-CO-180s-CO

ZW8-12 Product Variants

ZW8-12/T Type
The standard model with a spring operating mechanism. It can be combined with isolators and lightning arresters. The silicon rubber jacket provides weather resistance and anti-corrosion. Ideal for grid protection in challenging environments.

ZW8-12/C Type
Intelligent recloser type, equipped with a controller for automatic power recovery after transient faults. Supports single or multiple reclosing operations, inrush current control, and short-circuit fast breaking. Suitable for radial or ring power systems.

ZW8-12/PT Type
Includes a voltage transformer drawing power from the high-voltage line, supplying 220V/110V/100V for the breaker or other devices. Perfect for small hydro stations and rural substations with autonomous operation.

ZW8-12/ePT Type
Equipped with electronic PT and battery charging via CTs. Supports operation during power loss, integrates inrush control, overcurrent, and short-circuit protection. Allows wired or wireless remote control and is ideal for smart grid deployments.

The ZW8-12 Vacuum Circuit breaker guide offers a robust, modular, and intelligent solution for outdoor medium-voltage power protection. With multiple variants and upgrade options, it meets the needs of modern power distribution systems requiring fast fault clearing, automation, and long-term durability. Whether used in basic overload protection or full-featured smart grid applications, this vacuum circuit breaker ensures safety, reliability, and operational flexibility in all weather and load conditions.

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