ZW20-12F/630A Outdoor Intelligent High-voltage Vacuum Circuit Breaker

The ZW20 series outdoor high-voltage vacuum circuit breaker is a circuit protection device used for the user demarcation points of 10kV distribution networks, and is often called a "watchdog" due to its intelligent demarcation function. This device integrates protection, control and isolation functions, and is suitable for urban and rural distribution networks and smart grid construction.

I. Product Definition and Model

The ZW20-12 indoor high-voltage demarcation vacuum circuit breaker is mainly composed of three parts: the circuit breaker body, the fault detection controller and the external voltage transformer, which are connected through aviation sockets and sealed control cables.

Common models include ZW20-12F, ZW20A-12, ZW20B-12, etc. The meaning of the model is as follows:

ZW: Represents outdoor vacuum circuit breaker.

20: Represents the design serial number.

12: Represents the rated voltage of 12kV.

F: Represents with intelligent demarcation function.

The suffix parameter such as "/630-20" means the rated current is 630A and the rated short-circuit breaking current is 20kA.

II. Main Technical Parameters

The following are the core performance indicators of this series of circuit breakers:

III. Structure and Working Principle

1. Main Structure

The circuit breaker adopts a three-phase common-box sealed structure, and the box is filled with SF6 gas as the insulation and arc extinguishing medium, with explosion-proof performance. The main components include:

Circuit breaker body: Includes core components such as vacuum arc extinguishing chamber, conductive circuit, spring operating mechanism, current transformer, etc.

Intelligent controller: Realizes fault detection, protection logic judgment and remote control functions.

External voltage transformer: Provides secondary operating power for the controller and operating mechanism.

2. Intelligent Demarcation Function

Its core function is to accurately distinguish faults between the user side and the grid side:

It can detect milliampere-level zero-sequence current through the built-in zero-sequence current transformer to identify single-phase ground faults.

When a single-phase ground or phase-to-phase short-circuit fault occurs inside the user, the circuit breaker will trip automatically to isolate the fault and avoid affecting the upper-level power grid.

3. Operation Mode

Two operation modes, electric and manual, are provided to ensure reliability:

Electric operation: Receive instructions or automatically trigger through the controller, complete spring energy storage by the energy storage motor, and perform opening and closing operations.

Manual operation: Use a special energy storage handle for manual energy storage, and perform opening and closing operations through the manual opening and closing handle after the energy storage is in place. Note that if an intelligent controller is configured, the aviation socket should not be pulled out randomly, otherwise the equipment may be damaged.

IV. Installation and Usage Environment

Installation Direction: Generally installed horizontally, following the wiring principle of "incoming from the left, outgoing from the right".

Installation Method: Supports hoisting or bracket installation.

Environmental Conditions: Suitable for places with an altitude below 2000 meters, an ambient temperature ranging from -40℃ to +55℃ (different sources have differences, commonly -25℃ to +55℃), and free of flammable, explosive substances and severe vibration.

V. Core Features

High Reliability: Adopts vacuum arc extinguishing and SF6 gas insulation technology, and the sealed structure adapts to harsh outdoor environments.

Intelligentization: Integrates fault detection and automatic isolation functions, reduces the scope of power outages, and improves power supply reliability.

Dual Operation Modes: Has both electric and manual operations to ensure that manual opening and closing can still be performed when there is no operating power.

Long Service Life: The mechanical life is as high as 10000 times, and the contact system has low wear.

In summary, the ZW20 circuit breaker is a mature and fully functional column-mounted intelligent switching device, and it is a key device to improve the automation level and power supply reliability of 10kV distribution networks.