GCD isolation switch is applied in 12kVdistribution networksystem, with a rated current of 630A, sho-term withstand current of 20kA/4s, and peakwithstand current of 50kA. Both power frequency and lightning impulse withstand voltage can reach the level of 2000 meters above sea level.

1.Safety precautions

The personnel responsible for installing, maintaining, and operating the isolation switch should hold an instruction manual.Follow your company's safety regulations.

Before preparing to install, maintain, and operate the isolation switch, please carefully read the user manual to avoid incorrect operation of the switch, which may cause unnecessa personal inju or death.

Switches must be operated and maintained by professionals familiar with safety regulations. e instruction manual sees as a reference material for operation and maintenance personnel, and cannot be used as a substitute material for safety regulations training and internships for such equipment.

Main parameters of high-voltage isolation switch

Main Parameters of High Voltage Isolating Switches

High voltage isolating switches are essential components in electrical systems, ensuring safe disconnection and isolation of circuits for maintenance and repair. Understanding their key parameters is crucial for selecting the right switch for specific applications. Below are the primary parameters that define the performance and functionality of high voltage isolating switches.

1. Voltage Rating

The voltage rating is one of the most critical parameters of a high voltage isolating switch. It indicates the maximum voltage that the switch can safely handle without risk of electrical breakdown or arcing. This rating is usually expressed in kilovolts (kV). It is essential to choose a switch with a voltage rating that matches or exceeds the system’s operating voltage to ensure safety and reliability.

2. Current Rating

The current rating refers to the maximum current that the isolating switch can handle when it is in the closed position. This rating ensures that the switch will not overheat or experience damage during normal operation. The current rating is typically specified in amperes (A), and it should match the expected current flowing through the circuit during regular operation.

3. Breaking Capacity

Breaking capacity is the maximum short-circuit current the isolating switch can interrupt without causing damage to the switch or the surrounding system. This parameter is essential to prevent catastrophic failures during fault conditions. The breaking capacity is usually specified in kiloamperes (kA) and is determined based on the system's fault levels.

4. Mechanical Endurance

Mechanical endurance refers to the number of times the isolating switch can be operated (opened and closed) without failure due to wear or mechanical damage. This is an important consideration for switches used in systems where frequent switching is required. The mechanical endurance is typically specified in operations (e.g., 10,000 or 20,000 operations).

5. Electrical Endurance

Electrical endurance refers to the number of times the isolating switch can open and close under normal load or fault conditions without degradation in performance. This parameter is different from mechanical endurance and focuses on the switch’s ability to handle electrical stress over time. Electrical endurance is measured in operations and can be influenced by factors such as voltage and current ratings.

6. Insulation Resistance

Insulation resistance is a measure of the ability of the isolating switch to resist the flow of electrical current through its insulating components. High insulation resistance is essential to prevent leakage currents that can pose a safety hazard. It is typically measured in megohms (MΩ), and a higher resistance value indicates better insulating performance.

7. Contact Resistance

Contact resistance refers to the resistance at the point of contact when the switch is closed. Low contact resistance ensures minimal energy loss and prevents excessive heating of the contacts. This parameter is critical for maintaining the long-term efficiency of the isolating switch and is typically measured in milliohms (mΩ).

8. Switching Speed

Switching speed is the rate at which the isolating switch can open or close. Faster switching speeds are beneficial in preventing damage to the system during fault conditions, but the speed must be balanced with mechanical and electrical endurance to avoid excessive wear. Switching speed is typically specified in milliseconds.

9. Operating Temperature Range

The operating temperature range specifies the minimum and maximum temperatures at which the isolating switch can function reliably. It ensures that the switch can operate in diverse environmental conditions without compromising safety or performance. High voltage isolating switches are generally designed to operate in temperatures ranging from -40°C to 60°C, depending on the specific model.

10. Arc Extinguishing Capability

Arc extinguishing capability refers to the isolating switch’s ability to safely quench an electrical arc that occurs when the switch is operated under load or fault conditions. Switches with good arc extinguishing properties help prevent damage to the switch and surrounding equipment. The design of the switch, including its contacts and mechanisms, directly influences its arc quenching ability.

11. Installation and Mounting Type

The installation and mounting type of the isolating switch refer to how the switch is physically installed in the electrical system. Common types include indoor and outdoor mounting, wall-mounted, or on a switchgear panel. The mounting type influences the switch's accessibility, protection, and maintenance needs.

12. Degree of Protection (IP Rating)

The degree of protection, specified by the International Protection (IP) rating, defines the switch's resistance to environmental factors such as dust, moisture, and other external elements. A higher IP rating, such as IP55 or IP65, indicates better protection and suitability for harsh outdoor conditions.

Conclusion

When selecting a high voltage isolating switch, it is essential to consider these key parameters to ensure it meets the needs of the electrical system. Factors such as voltage rating, current rating, breaking capacity, and insulation resistance play a significant role in the switch’s reliability and performance. By understanding these parameters, you can make an informed decision when choosing the right isolating switch for your application, ensuring safety, efficiency, and long-term durability.