Product Introduction

Outdoor vacuum circuit breakers are core switching devices designed specifically for outdoor high-voltage distribution scenarios. They use vacuum as the arc-extinguishing medium and have the ability to withstand harsh environments such as wind, rain, extreme temperatures, and dust. They are mainly used for line control, short-circuit protection, and load switching in medium and high voltage power grids of 10kV, 20kV, 35kV, etc. They are key equipment in outdoor substations, distribution transformer areas, wind power/photovoltaic power stations, and other scenarios.

Features and Advantages

The core features of outdoor vacuum circuit breakers are "vacuum arc extinguishing + outdoor protection":

Vacuum arc extinguishing: Utilizing the high insulation of vacuum (vacuum degree usually ≥10⁻⁴Pa) and zero gas ionization characteristics, it quickly extinguishes arcs (arc extinguishing time only 0.01~0.02 seconds), oil-free, SF₆ gas-free (in some models), environmentally friendly and maintenance-free for arc-extinguishing medium;

Outdoor protection: The cabinet or main body adopts sealed and anti-corrosion design, meeting IP54 and above protection levels (dustproof, splash-proof). Some models can withstand extreme temperatures from -40℃ to +70℃, suitable for complex environments such as the wild and high altitudes.

Working Principle

The working logic of the outdoor vacuum circuit breaker revolves around "closing and opening control → vacuum arc extinguishing → line protection," with the specific process as follows:

Closing process:

The electric or manual trigger operating mechanism releases the pre-compressed closing spring energy, driving the moving contact inside the vacuum arc extinguishing chamber toward the fixed contact through a linkage;

After the moving and fixed contacts touch, the conductive circuit is connected, and the line is normally powered; at this time, the opening spring is simultaneously compressed and stores energy, preparing for the next opening.

Opening and arc extinguishing process:

When the line experiences a short circuit, overload (detected by the protection device), or manual opening is required, the operating mechanism triggers the opening spring release, driving the moving contact to quickly move away from the fixed contact;

The arc generated at the moment of contact separation is rapidly extinguished because there is no gas molecule ionization in the vacuum environment. The arc energy is quickly absorbed by the contact material (copper-chromium alloy), extinguishing instantly (extinguishing time is extremely short, with no risk of arc overflow);

After opening, the vacuum arc extinguishing chamber maintains a high insulation state, cutting off the line current to achieve reliable power disconnection.

Protection linkage:

If the line current is abnormal (such as a short circuit), the current transformer converts the large current into a small signal and transmits it to the matching protection device (such as an outdoor intelligent controller). The protection device triggers the circuit breaker to open, preventing fault expansion.

Core Advantages

Environmentally friendly and maintenance-free: No insulating oil (avoiding oil leakage pollution), no SF₆ greenhouse gas (in some models), vacuum arc extinguishing chamber life exceeds 20 years, no need to replace arc-extinguishing medium in daily use, low maintenance cost;

Excellent arc extinguishing performance: Vacuum arc extinguishing speed is fast, no arc spatter during opening, suitable for flammable outdoor environments (such as forest areas, near oil depots), high safety;

Strong environmental adaptability: IP54 and above protection level, cabinet anti-corrosion (powder coating/stainless steel), resistant to high and low temperatures (-40℃~+70℃), lightning protection (some with zinc oxide arresters), suitable for use in plateaus, coastal areas, deserts, and other scenarios;

Reliable operation: Spring operating mechanism ensures stable opening and closing speed (not affected by ambient temperature), supports remote electric operation (compatible with smart grids), and can also be manually operated in emergencies, suitable for unattended transformer areas;

Compact and lightweight: Compared with oil-immersed circuit breakers, weight is reduced by 30%~50%, reducing the load requirements on utility poles when mounted on poles, making installation convenient.

Typical Application Scenarios

Rural/urban distribution networks: 10kV pole-mounted vacuum circuit breakers are used for incoming line control in distribution transformer areas, achieving line segmentation and fault isolation (e.g., cooperating with intelligent reclosing to reduce outage scope);

New energy power stations: On the 35kV outgoing side of wind and photovoltaic power stations, used for switch control and short-circuit protection of grid-connected lines, suitable for outdoor open-air installation environments;

Industrial outdoor distribution: Outdoor high-voltage lines in chemical plants and mining areas, avoiding oil leakage risks of oil-immersed circuit breakers, while resisting corrosive gases or dust;

Temporary power supply scenarios: Temporary high-voltage distribution for infrastructure construction sites and emergency repairs, small size, quick installation, enabling rapid power restoration.