GW4 Outdoor High Voltage Disconnector

Product Overview

The GW4 Outdoor High Voltage Disconnector is an outdoor AC high-voltage isolating switch designed for substations, transmission lines and medium- to high-voltage power distribution systems. Its primary function is to provide a visible and reliable electrical isolation point for maintenance, inspection and system sectionalizing.

The defining feature of the GW4 is its double-column horizontal-rotation center-break structure. Each pole uses two supporting insulator columns, with the conductive contact assembly rotating horizontally to establish or separate the electrical connection at the center break. This configuration provides a large visible isolation distance and stable mechanical operation, making the GW4 suitable for outdoor substation applications. :contentReference[oaicite:1]{index=1}

Technical Specifications

Parameter	Unit	Specification
Model	—	GW4
Product Type	—	Outdoor High Voltage AC Disconnector
Structural Type	—	Double-Column Horizontal-Rotation Center-Break
Rated Voltage	kV	12 / 40.5, According to Configuration
Rated Frequency	Hz	50
Rated Current	A	400–2000, According to Configuration
4s Short-Time Withstand Current	kA	20 / 25 / 31.5 / 40
Peak Withstand Current	kA	50 / 63 / 80 / 100
Power Frequency Withstand Voltage to Earth	kV / 1min	42 / 95, According to Voltage Class
Power Frequency Withstand Voltage Across Open Contacts	kV / 1min	49 / 118, According to Voltage Class
Lightning Impulse Withstand Voltage to Earth	kV peak	75 / 185, According to Voltage Class
Lightning Impulse Withstand Voltage Across Open Contacts	kV peak	85 / 215, According to Voltage Class
Number of Poles	—	3
Grounding Arrangement	—	None / Single-Side / Double-Side Grounding
Operating Mechanism	—	Manual / Motorized
Operating Mode	—	Single-Pole or Three-Pole Linked Operation
Mechanical Life	Operations	3,000
Installation	—	Outdoor

Applications
Outdoor Substations

Used for isolating transformers, busbars, feeders and other high-voltage equipment in outdoor substations.

Transmission Lines

Provides visible isolation for overhead transmission and distribution lines during maintenance and sectionalizing operations.

Transformer Bays

Suitable for isolating transformer connections and creating a clearly identifiable maintenance isolation point.

Renewable Energy Substations

Suitable for outdoor substations associated with photovoltaic, wind power and other grid-connected generation systems.

Key Features
01Double-Column Structure

Two supporting insulator columns are used on each pole, forming the characteristic GW4 double-column configuration.

02Horizontal Rotation

The conductive knife rotates horizontally around the supporting columns, providing smooth operation and a compact mechanical arrangement.

03Center-Break Isolation

The center-break design creates a large visible isolation gap when the switch is in the open position.

04Flexible Grounding Options

The GW4 can be configured without grounding, with single-side grounding or with double-side grounding according to project requirements.

05Manual or Motorized Operation

Manual mechanisms are suitable for conventional installations, while motorized mechanisms support remote operation and substation automation.

06Outdoor High-Voltage Design

Designed for outdoor substations and transmission environments with insulation and mechanical configurations selected according to voltage class.

Double-Column Horizontal-Rotation Center-Break Structure

The double-column center-break structure is the characteristic design of the GW4 series. Each phase is supported by two insulator columns mounted on the base. The conductive blades are connected to the rotating supports and move horizontally during opening and closing.

As the operating mechanism moves, the two insulating columns rotate in opposite directions and the conductive contacts separate at the center of the pole. This produces a clearly visible open gap while keeping the overall arrangement mechanically stable.

The center-break arrangement is particularly suitable for outdoor substations because the opening position is visually easy to identify and the large contact separation provides a clear isolation point. :contentReference[oaicite:2]{index=2}

Contact System & Mechanical Design

The GW4 contact system is designed for reliable current carrying and repeated mechanical operation. The rotating contact assembly is driven through a linkage mechanism that coordinates the movement of the two columns.

The contact arrangement can be designed with self-cleaning characteristics and high-strength conductive contact materials to improve contact reliability and reduce the effects of oxidation and contamination during long-term outdoor operation.

The three poles can operate independently or be mechanically linked through connecting rods for coordinated three-phase operation. :contentReference[oaicite:3]{index=3}

Grounding & Interlocking

The GW4 can be supplied with single-side or double-side grounding switches according to the requirements of the substation or transmission line. Grounding configurations are available where the isolated section needs to be safely grounded during maintenance.

Mechanical and electrical interlocking can be incorporated to coordinate the main disconnector, grounding switch and circuit breaker. This arrangement helps prevent incorrect operating sequences, such as closing a grounding switch while the main circuit remains energized.

The exact interlocking arrangement should be coordinated with the complete switchgear and substation control design. :contentReference[oaicite:4]{index=4}

Substation & System Integration

GW4 disconnectors are commonly installed at transformer bays, busbar sections, incoming and outgoing line bays and other primary isolation points in outdoor substations.

The disconnector can be integrated with circuit breakers, current transformers, voltage transformers, surge arresters and grounding equipment as part of a complete high-voltage substation bay.

Motorized operating mechanisms can also be selected for remote switching, position indication and substation automation systems. :contentReference[oaicite:5]{index=5}

Electrical Isolation & Safe Operation

The GW4 is primarily an isolating device and is not intended to replace a circuit breaker for normal load-current or fault-current interruption. It is normally operated after the corresponding circuit breaker has interrupted the current and the circuit has been safely de-energized.

The center-break configuration provides a clearly visible isolation gap. When an earthing device is included, the grounding switch should only be operated after the main disconnector has reached the required open position and the prescribed interlocking conditions have been met.

Outdoor Environmental Performance

The GW4 series is designed for outdoor service and can be configured for different pollution and environmental conditions. Typical referenced service conditions include ambient temperatures from approximately -40°C to +45°C, wind speeds up to 35m/s and altitude requirements according to the selected product configuration.

Anti-pollution versions are available for areas with higher contamination levels, and the required creepage distance and insulation design should be selected according to the local environmental conditions. 

Operating Conditions

• Outdoor installation in substations, transmission lines and distribution systems
• Ambient temperature: approximately -40°C to +45°C, depending on configuration
• Altitude: according to selected model and service conditions
• Maximum wind speed: up to approximately 35m/s
• Suitable grounding and pollution configurations available
• Seismic intensity: up to approximately 8 degrees under referenced conditions
• Exact environmental limits should be confirmed according to the final product configuration and installation site