Top 10 High-Voltage Circuit Breaker Brand & Manufacturers

What is a High-Voltage Circuit Breaker?

A high-voltage circuit breaker is a critical electrical device used in power systems to interrupt the flow of high-voltage current. It is designed to protect the electrical network and connected equipment from damage caused by over-current conditions such as short-circuits and overloads. These breakers are capable of handling voltages typically above 35 kV and are usually installed in power substations and transmission lines.

History of High-Voltage Circuit Breaker

• Early Development: The concept of circuit breakers dates back to the late 19th century when the need to protect electrical systems from faults became evident. Early circuit breakers were simple mechanical devices used in low-voltage applications. As power systems grew and voltages increased, the development of high-voltage circuit breakers began. The first high-voltage air-blast circuit breakers were developed in the early 20th century, which used compressed air to extinguish the arc formed during current interruption.
• Technological Advancements: With the expansion of the power industry, more efficient and reliable circuit-breaker technologies emerged. The introduction of oil-filled circuit breakers provided better arc-quenching capabilities. Later, sulfur hexafluoride (SF?) gas-insulated circuit breakers were developed. SF? offered excellent dielectric and arc-quenching properties, allowing for more compact and high-performance circuit breakers. In recent years, there has been a trend towards the development of vacuum circuit breakers for high-voltage applications as well.
• Modern Developments: Modern high-voltage circuit breakers incorporate advanced control and monitoring systems. Digital technology enables real-time monitoring of breaker status, remote operation, and integration with the overall power-management system. Additionally, there is a growing emphasis on environmental-friendly and energy-efficient designs to reduce the impact of circuit-breaker operation and maintenance.

Purpose of High-Voltage Circuit Breaker

• Over-Current Protection: The primary purpose of a high-voltage circuit breaker is to protect the power system from over-current conditions. When a short-circuit or overload occurs, the breaker quickly interrupts the current flow to prevent damage to transformers, generators, transmission lines, and other connected equipment. This protection is crucial for maintaining the integrity and reliability of the power grid.
• Fault Isolation: In the event of a fault, the circuit breaker isolates the faulty section of the power system. By doing so, it prevents the fault from spreading to other healthy parts of the network, minimizing the scope of the outage and facilitating faster restoration of power to unaffected areas.
• System Control and Maintenance: High-voltage circuit breakers also play a role in system control. They can be used to switch circuits during normal operation, such as for maintenance purposes or to redirect power flow. Their ability to interrupt current allows for the safe disconnection of equipment for inspection, repair, or replacement.

Principle of High-Voltage Circuit Breaker

• Arc Formation and Interruption: When a high-voltage circuit breaker opens to interrupt the current, an arc is formed between the contacts due to the ionization of the medium (such as air, oil, or gas) between them. The key principle of the circuit breaker is to quickly extinguish this arc. Different types of circuit breakers use various methods to achieve this. For example, in an SF? gas-insulated circuit breaker, the SF? gas absorbs the energy of the arc and cools it rapidly, causing the arc to extinguish.
• Dielectric Recovery: After the arc is extinguished, the circuit breaker must quickly recover its dielectric strength to prevent re-ignition of the arc. The insulating medium (e.g., the SF? gas or vacuum) is designed to have a high dielectric strength to withstand the system voltage once the current is interrupted. The design of the breaker's contacts and the insulation system is optimized to ensure rapid dielectric recovery.
• Control and Tripping Mechanism: High-voltage circuit breakers are equipped with a control system that monitors the current and voltage in the circuit. When a fault condition is detected, a tripping signal is sent to the breaker's operating mechanism. The operating mechanism, which can be mechanical, hydraulic, or pneumatic, then quickly opens the contacts to interrupt the current. The speed of operation is critical to limit the amount of energy dissipated during a fault.

Features of High-Voltage Circuit Breaker

• High-Voltage and High-Current Handling: These circuit breakers are designed to handle high-voltage and high-current levels. They have the capacity to interrupt currents ranging from thousands to tens of thousands of amperes and voltages up to several hundred kilovolts. This allows them to protect large-scale power-transmission and-distribution systems.[!--empirenews.page--]
• Fast Operation: High-voltage circuit breakers are capable of very fast operation. They can interrupt the current within a few milliseconds to tens of milliseconds, depending on the type and design. This rapid response time is essential for minimizing the damage caused by faults and maintaining the stability of the power grid.
• Excellent Arc-Quenching Capability: The ability to effectively quench the arc formed during current interruption is a crucial feature. Different types of circuit breakers, such as those using SF? gas or vacuum insulation, have excellent arc-quenching mechanisms that ensure reliable and repeatable interruption of current.
• High-Reliability Design: Given their critical role in power systems, high-voltage circuit breakers are designed for high reliability. They are built with robust materials and components and undergo extensive testing to ensure they can operate under a wide range of environmental and electrical conditions without frequent failures.
• Remote-Monitoring and Control Capability: Many modern high-voltage circuit breakers are equipped with communication interfaces that allow for remote-monitoring and-control. This enables operators to monitor the breaker's status, receive fault-alerts, and even remotely operate the breaker from a control center.

Types of High-Voltage Circuit Breaker

• SF? Gas-Insulated Circuit Breaker: These breakers use sulfur hexafluoride (SF?) gas as the insulating and arc-quenching medium. SF? gas has excellent dielectric strength and arc-quenching properties. The gas is enclosed in a sealed chamber, and when the contacts open, the gas absorbs the energy of the arc and extinguishes it. SF? circuit breakers are widely used in high-voltage power-transmission and-distribution systems due to their high performance and compact design.
• Vacuum Circuit Breaker: Vacuum circuit breakers operate in a vacuum environment. When the contacts separate and an arc is formed, the lack of a gaseous medium causes the arc to be quickly extinguished due to the rapid diffusion of metal vapor from the contacts. Vacuum circuit breakers are becoming more popular for high-voltage applications, especially in medium-voltage to high-voltage range, because they are environmentally friendly and have a long-service life.
• Oil-Filled Circuit Breaker: In an oil-filled circuit breaker, the contacts are immersed in insulating oil. When the contacts open and an arc is formed, the oil vaporizes around the arc, and the hydrogen gas generated helps to extinguish the arc. Oil-filled circuit breakers were widely used in the past but are now being phased out in many applications due to environmental and safety concerns related to the oil.
• Air-Blast Circuit Breaker: These breakers use a blast of compressed air to extinguish the arc. The high-velocity air flow cools and de-ionizes the arc path, interrupting the current. Air-blast circuit breakers were among the early types of high-voltage circuit breakers and are still used in some specific applications where their characteristics are suitable.

Precautions for using High-Voltage Circuit Breaker

• Proper Installation: High-voltage circuit breakers must be installed correctly according to the manufacturer's instructions and relevant electrical codes. The installation process includes proper alignment of the breaker, connection of the high-voltage conductors, and ensuring correct grounding. Incorrect installation can lead to improper operation, increased risk of faults, and safety hazards.
• Regular Maintenance: Regular maintenance is essential to ensure the reliable operation of high-voltage circuit breakers. This includes inspection of the contacts for wear and erosion, checking the integrity of the insulating medium (such as the SF? gas pressure or vacuum level), and testing the operating mechanism. Maintenance should be carried out by trained personnel using appropriate tools and procedures.
• Over-Voltage and Over-Current Protection of the Breaker: Although the circuit breaker is designed to protect the power system from over-current and over-voltage conditions, it itself needs protection. Surge-arresters and other protective devices should be installed in the circuit to prevent damage to the breaker from external over-voltages and transient over-currents.
• Environmental Considerations: Consider the environmental conditions where the breaker is installed. For example, in the case of SF? circuit breakers, any leakage of SF? gas can have a significant environmental impact due to its high global-warming potential. Adequate ventilation and gas-monitoring systems may be required. For outdoor installations, protection from extreme weather conditions such as rain, snow, and temperature fluctuations is also important.[!--empirenews.page--]
• Control-System Integrity: Ensure the integrity of the breaker's control system. The control signals and communication lines should be properly shielded and protected from electromagnetic interference. Any malfunction in the control system can lead to incorrect operation of the breaker and potential power-system failures.

Things to consider when purchasing High-Voltage Circuit Breaker

• Voltage and Current Ratings: Determine the maximum voltage and current that the circuit breaker will need to handle in your power system. Choose a breaker with appropriate voltage and current-handling capabilities, with some margin for safety and future expansion of the system. Consider the short-circuit current-carrying capacity as well, as this is a critical factor for fault-handling.
• Type of Circuit Breaker: Select the most suitable type of high-voltage circuit breaker based on your specific requirements. Consider factors such as the application environment, performance requirements, and cost-effectiveness. For example, SF? gas-insulated breakers are suitable for high-performance and compact-design requirements, while vacuum breakers may be preferred for their environmental-friendliness and long-service-life characteristics.
• Operation Speed and Tripping Characteristics: Look for a circuit breaker with a fast operation speed and appropriate tripping characteristics. The tripping time and characteristics should match the requirements of your power-system protection scheme to ensure quick and effective fault-isolation. Some breakers may offer adjustable tripping settings to customize the protection.
• Maintenance Requirements and Cost: Consider the maintenance requirements of the circuit breaker. Some types may require more frequent maintenance than others. Evaluate the cost of maintenance, including the cost of replacement parts, labor, and any specialized equipment or tools needed. A breaker with lower maintenance requirements and costs may be more favorable in the long run.
• Remote-Monitoring and Control Features: If remote-monitoring and-control capabilities are important for your power-system operation, choose a circuit breaker with suitable communication interfaces and control-software support. This allows for better integration with the overall power-management system and more efficient operation and maintenance.
• Brand and Reputation: Select a reputable brand with a good track-record in manufacturing high-voltage circuit breakers. Read customer reviews and ask for recommendations from other power-system operators or industry experts to assess the quality, reliability, and performance of different models. A well-known brand is more likely to provide reliable customer service and technical support.
• Cost: Establish a budget for the circuit-breaker purchase. The cost can vary significantly depending on the voltage and current ratings, type, and features of the breaker. Consider not only the initial purchase price but also the long-term costs, such as maintenance, energy losses (if applicable), and potential replacement costs. A more expensive, high-quality breaker may be a more cost-effective choice in the long run if it offers better performance and reliability.

Terms of High-Voltage Circuit Breaker

• Breaking Capacity: The maximum current that a circuit breaker can interrupt under specific conditions, usually specified in kiloamperes (kA). It is a key parameter for determining the breaker's ability to handle short-circuit currents and protect the power system.
• Making Capacity: The maximum current that a circuit breaker can close onto without damage. It is related to the inrush current that can occur when a circuit is energized and is an important consideration for the breaker's mechanical and electrical design.
• Interrupting Time: The time from the detection of a fault to the complete interruption of the current by the circuit breaker. It includes the time for the control system to send the tripping signal and the time for the breaker's operating mechanism to open the contacts and extinguish the arc. A shorter interrupting time is generally preferred for better power-system protection.
• Dielectric Withstand Voltage: The maximum voltage that the circuit breaker's insulation can withstand without breakdown. It is usually specified as a value for both AC and DC voltages and is an important parameter for ensuring the breaker's safety and reliability in high-voltage applications.
• Contact Resistance: The resistance at the interface between the breaker's contacts. Low contact resistance is desirable to minimize power losses and heat generation during normal operation and to ensure efficient current transfer. High contact resistance can lead to overheating and premature wear of the contacts.[!--empirenews.page--]