Product Overview
The ZW8-12/C is an intelligent three-phase 12 kV 50 Hz outdoor vacuum circuit breaker for overhead feeder networks, breaking and closing load currents with integrated overload, short-circuit, instantaneous and time-delayed protection plus automatic reclosing in one self-powered pole-mounted unit. Rated currents of 400 A and 630 A pair with breaking capacities of 12.5, 16 and 20 kA, and built-in CT/PT interfaces support SCADA telemetry; an optional arrester or disconnector combination is available.
Product Display
Model Designation
Model format: ZW 8 − 12 / C
- Z — Vacuum circuit breaker
- W — Outdoor type
- 8 — Design sequence number
- 12 — Rated voltage (kV)
- /C — Intelligent type with built-in automatic reclosing
Service Conditions
- Ambient air temperature: −40 °C to +40 °C
- Altitude: not exceeding 1000 m (higher altitude on request with derating)
- Earthquake intensity: not exceeding Grade 8
- Relative humidity: daily average ≤ 95%, monthly average ≤ 90%
- Site free from fire, explosion risk, severe pollution, chemical corrosion and violent vibration
Construction
The ZW8-12/C uses a compact three-phase column structure with vacuum interrupters housed inside a stainless-steel sealed tank, mounted on a galvanised steel frame for pole or gantry installation. The external mechanism box contains the spring-storage mechanism, control board and communication module, and the hermetically sealed interrupters give a long maintenance-free service life in harsh outdoor environments.
An integrated intelligent controller (FTU) provides overcurrent relay protection, instantaneous trip, time-delayed overcurrent and auto-reclosing of one to three operations, with remote/local switching and a manual operating handle for emergency use. The built-in power supply derives operating energy from the line, so local or remote operation needs no external DC or AC source.
Technical Data
| Item | Unit | Value |
|---|---|---|
| Rated Voltage | kV | 12 |
| Power Frequency Withstand Voltage (dry / wet) | kV | 42 / 34 |
| Lightning Impulse Withstand Voltage (peak) | kV | 75 |
| Rated Current | A | 400 630 |
| Rated Short-Circuit Breaking Current | kA | 20 16 12.5 |
| Rated Operating Sequence | — | O-0.3s-CO-180s-CO |
| Rated Short-Circuit Breaking Operations | Times | 30 |
| Rated Short-Circuit Closing Current (peak) | kA | 50 |
| Rated Peak Withstand Current | kA | 50 |
| Rated Short-Time Withstand Current | kA | 20 16 12.5 |
| Rated Short-Circuit Duration | s | 4 |
| Opening Time (shunt trip, highest / rated / lowest voltage) | ms | 15-50 15-50 30-60 |
| Closing Time | ms | 25-50 |
| Total Opening Time | ms | ≤ 100 |
| Arcing Time | ms | ≤ 20 |
| Mechanical Life | Times | 10000 |
| Closing Energy | J | 70 |
| Storage Motor Rated Input Power | W | ≤ 220 |
| Operating / Auxiliary Circuit Voltage | V | AC/DC 220, 110, 24 |
| Storage Time at Rated Voltage | s | < 8 |
| Overcurrent Trip Unit (rated current / accuracy) | A / % | 5 / ± 10 |
| Overcurrent Setting Range | A | 1-9 |
| Instantaneous Trip Setting Range | — | 6-20 |
| Time Delay Range | ms | 80-500 |
| Remote Control Distance | m | 30 |
| Auto-Reclosing Operations | Times | 1-3 |
Standards
Manufactured and tested in accordance with IEC and GB standards for high-voltage AC circuit breakers, including IEC 62271-100 and GB 1984.
Installation & Dimensions
Installation Diagram
The breaker is designed for pole-mounted or gantry installation; the drawings give overall and installation dimensions for both the electronic-PT type circuit breaker and the recloser variant. Phase-to-phase clearance, grounding and the mechanical load rating of the support structure are verified during installation.
| Dimension | Electronic PT Type | Recloser |
|---|---|---|
| Overall Width | 1030 | 830 |
| Overall Depth | 510 | 560 |
| Overall Height | 800 | 1050 |
| Installation Hole Spacing | 590 × 480 | 590 × 480 |
| Installation Holes | 4 × φ15 | 4 × φ15 |