After years of deep technical cultivation and co‑innovation with users, Bepto delivers fast, reliable and scalable customized insulator solutions worldwide.
Short Answer: A vacuum interrupter consists of an insulating envelope, fixed and moving contacts, a shield, and a bellows. Its core function is to rapidly extinguish an electrical arc in a vacuum.
Detailed Explanation: A vacuum interrupter is the “heart” of a medium-voltage vacuum circuit breaker. Its basic structure includes:
1) Insulating Envelope: Typically made of ceramic, it maintains the internal high vacuum (usually below 10⁻⁴ Pa) and provides electrical insulation.
2) Fixed and Moving Conductors: These form the current path. The fixed conductor is stationary, while the moving conductor moves axially via the bellows.
3) Contacts: Made of special alloy materials (e.g., CuCr), this is where the current is made or broken. Their specific geometry (e.g., axial magnetic field type) helps to quickly extinguish the arc.
4) Shield: Located inside the envelope, it protects the insulating surface from metal vapor generated by the arc.
5) Bellows: A flexible metal component that allows the moving conductor to travel while maintaining the vacuum seal. Its function is to create an arc when the contacts separate; because the medium density in a vacuum is extremely low, the arc cannot be sustained and extinguishes at the first current-zero crossing, thus achieving rapid current interruption.
Short Answer: To select the right insulated operating rod, consider four key parameters: rated voltage, mechanical strength (bending and tensile), overall length, and the dimensions of the mounting interfaces.
Detailed Explanation: An insulated operating rod is crucial for transmitting operating force while isolating high voltage. Proper selection is vital.
1) Rated Voltage: You must choose a rod with a voltage rating that matches or exceeds that of the switchgear (e.g., 12kV, 24kV, 40.5kV) to ensure an adequate insulation safety margin.
2) Mechanical Strength: Based on the force and torque from the operating mechanism (e.g., spring or magnetic actuator), calculate the maximum tensile/compressive force and bending moment the rod must withstand. Select a model with sufficient rated tensile strength (N) and bending strength (N·m) from our datasheet.
3) Length and Interfaces: The overall length and the type, thread specifications, and hole dimensions of the metal end fittings must exactly match the switchgear’s mechanical design for proper installation and reliable operation.
4) Operating Environment: For outdoor or highly polluted environments, the material’s weather resistance and anti-flashover properties must also be considered.
Short Answer: Gas Insulated Switchgear (GIS) bushings offer the core advantages of a compact design, excellent insulation performance, strong environmental adaptability, maintenance-free operation, and high reliability.
Detailed Explanation: GIS bushings are the critical interface connecting GIS to overhead lines or transformers. Their advantages are significant:
1) Compact Structure: Due to the excellent insulation properties of SF6 or eco-friendly gases, GIS bushings are much smaller than traditional porcelain bushings of the same voltage class, saving considerable substation space.
2) Superior Insulation: The interior uses composite insulation like Epoxy Resin Impregnated Paper (ERIP) or Resin Impregnated Synthetics (RIS), filled with high-pressure insulating gas. This provides extremely high dielectric strength and very low partial discharge levels.
3) Strong Environmental Adaptability: The core insulation is hermetically sealed, making it immune to external factors like humidity, pollution, and altitude.
4) Maintenance-Free: The external housing is typically made of a composite silicone rubber with excellent hydrophobicity and pollution resistance, eliminating the need for periodic cleaning and enabling maintenance-free operation throughout its service life.
Short Answer: Key accessories for an indoor SF6 load break switch include an SF6 gas density monitor, an insulated operating rod, specific epoxy resin insulators, and an auxiliary switch with an earthing interlock.
Detailed Explanation: To ensure the safe and reliable operation of an indoor SF6 load break switch, several accessories are essential.
1) SF6 Gas Density Monitor: This is the most critical safety device. It continuously monitors the SF6 gas density inside the switch. If the density drops to a preset alarm or lockout value due to a leak, it sends a signal to alert personnel or block the switch’s operation, preventing an operation under insufficient insulation conditions.
2) Epoxy Resin Insulators: This includes post insulators that support the switch mechanism and partition plates for phase-to-phase insulation. They must be made of an epoxy material compatible with SF6 gas.
3) Insulated Operating Rod: This transmits the force from the manual or motor-driven mechanism while isolating high voltage.
4) Auxiliary Switch: This provides remote signaling of the main contact’s position (open/closed) and enables a mechanical interlock with the earthing switch to prevent operational errors.
Short Answer: An insulator’s core functions are mechanical support and electrical insulation. A sensor, while also an insulator, integrates additional voltage or current measurement capabilities.
Detailed Explanation: Although they may look similar and are both made of epoxy resin for use in switchgear, their functions are fundamentally different. A Switchgear Insulator is a passive component designed to provide reliable mechanical support (e.g., for a busbar) and sufficient electrical insulation (to withstand system voltage and overvoltages). Its performance is measured by its mechanical strength (e.g., cantilever strength) and insulation level (e.g., lightning impulse withstand voltage). A Switchgear Sensor is an intelligent insulator. During the epoxy casting process, a high-precision capacitive divider (for voltage sensing) or a Rogowski coil (for current sensing) is embedded inside. Therefore, it not only performs all the functions of an insulator but also provides a real-time, accurate low-voltage output signal proportional to the primary voltage or current. It combines the functions of a traditional insulator and an instrument transformer, making switchgear more compact and intelligent.
Short Answer: Using an epoxy resin embedded pole encases the vacuum interrupter and main circuit into a single solid unit, improving the circuit breaker’s mechanical stability, insulation reliability, and making it maintenance-free.
Detailed Explanation: Epoxy resin embedded pole technology is a major innovation in medium-voltage vacuum circuit breakers. Its key advantages include:
1) Enhanced Insulation Performance: By encapsulating the vacuum interrupter and the primary conductive parts within epoxy resin using the APG process, it eliminates air interfaces. This protects the vacuum interrupter’s surface from dust, moisture, and condensation, dramatically improving insulation reliability and pollution resistance.
2) Increased Mechanical Stability: The solid construction makes the entire pole a robust unit, effectively protecting the fragile vacuum interrupter from mechanical stresses caused by short-circuit electrodynamic forces and transportation vibrations.
3) Compact and Maintenance-Free Design: The compact structure allows for smaller phase-to-phase distances, facilitating the miniaturization of switchgear. Since the internal components are completely shielded from the external environment, the embedded pole is maintenance-free for its entire service life.
Short Answer: Our eco-friendly gas series insulation parts are designed for switchgear that uses SF6 alternatives, having a Global Warming Potential (GWP) of nearly zero, which significantly reduces greenhouse gas emissions.
Detailed Explanation: Sulfur hexafluoride (SF6) is an excellent insulating gas, but its Global Warming Potential (GWP) is 23,500 times that of CO₂, and it is listed as a restricted greenhouse gas under the Kyoto Protocol. Our eco-friendly gas series insulation parts were developed to address this challenge. The materials and structures of these components (e.g., bushings, insulators, partition plates) are optimized for the insulation properties of clean air, nitrogen, or other gas mixtures. Using these parts with their corresponding eco-friendly gases instead of traditional SF6 solutions reduces the GWP of the switchgear from tens of thousands to near zero. This not only helps our clients comply with increasingly strict environmental regulations but is also a significant step in transitioning the entire power industry towards a low-carbon, sustainable future.
Short Answer: Our 40.5kV series insulation parts are primarily used in 35kV electrical power systems, commonly found in urban substations, wind farms, and the power distribution networks of large industrial facilities.
Detailed Explanation: 40.5kV is a key voltage class in medium-voltage grids, corresponding to a nominal system voltage of 35kV. Our 40.5kV series insulation components—including switchgear insulators, sensors, contact boxes, wall bushings, and embedded poles—are the core components of switchgear and circuit breakers at this voltage level. Typical applications include:
1) Urban Power Grids: Used in regional substations and switching stations for the control and protection of power lines.
2) Renewable Energy: In wind farms and large-scale solar plants, they are used to collect and transmit the power generated from multiple units to the main grid.
3) Heavy Industry: In energy-intensive enterprises such as steel mills, petrochemical plants, and mines, they are used to supply power to large high-voltage motors, electric furnaces, and other heavy equipment. These applications demand extremely high reliability, placing stringent requirements on the quality and performance of 40.5kV insulation parts.
Short Answer: The two processes suit different applications. Molded insulation (e.g., SMC/BMC) is cost-effective for high-volume, simple, low-voltage parts. Epoxy resin casting offers superior performance for high-voltage, complex, critical components.
Detailed Explanation: Molding and casting are two primary manufacturing processes for solid insulation parts. The Molded Insulation Series typically uses thermosetting materials like SMC (Sheet Molding Compound) or BMC (Bulk Molding Compound), which are compression-molded under high heat and pressure. The advantages are high production efficiency and low cost, making it ideal for mass-produced items like low-voltage insulators, partition plates, and support brackets. However, its material flow is limited, making it unsuitable for complex parts with intricate metal inserts. Epoxy Resin Casted Parts are typically made using the APG process, where liquid epoxy resin is injected into a mold under vacuum and pressure. Its advantages are exceptional electrical and mechanical properties and the ability to achieve a seamless bond with metal inserts. This makes it ideal for technically demanding, high-voltage components like embedded poles, high-voltage sensors, and GIS disc insulators. The choice depends on the voltage level, structural complexity, and cost target of the application.
Short Answer: The keys to properly installing a switchgear insulating bushing are: cleaning the insulation surface, tightening the mounting flange bolts evenly, and ensuring a good connection with the conductor.
Detailed Explanation: The quality of installation for a switchgear insulating bushing (such as a wall bushing or apparatus bushing) directly impacts its long-term reliability. Follow these steps:
1) Thoroughly Clean: Before installation, use a lint-free cloth and a recommended cleaning agent (e.g., isopropyl alcohol) to wipe the epoxy surface clean of any grease, dust, or moisture.
2) Check the Gasket: Ensure the sealing gasket on the mounting flange is clean, undamaged, and correctly seated in its groove.
3) Evenly Tighten Bolts: When fixing the bushing to the switchgear panel, you must use a torque wrench. Tighten the bolts in a crisscross pattern over 2-3 stages until they reach the specified torque value. This ensures even pressure and a proper seal.
4) Conductor Connection: When connecting the high-voltage conductor, ensure the contact surfaces of the terminal and the bushing are flat and clean. Apply a thin layer of conductive grease, then tighten the connecting bolts to the specified torque to prevent overheating.
Short Answer: Our conductive connector series primarily uses high-conductivity T2 copper or 6061/6063 aluminum alloy as the base material, with silver or tin plating applied based on the application requirements.
Detailed Explanation: The core performance of a conductive connector is defined by low resistance and high reliability, which is determined by the material.
1)Base Material: For critical components carrying large currents, such as the tulip contacts inside a switchgear contact box, we use T2 copper (electrolytic copper), which has a conductivity of over 99% IACS and good elasticity. For busbar connectors and terminals, we offer either T2 copper or high-strength conductive aluminum alloy (e.g., 6061 grade), depending on the client’s cost and weight requirements.
2)Surface Plating: To reduce contact resistance and prevent oxidation, all copper connectors are silver-plated with a thickness of at least 5μm. The silver layer provides excellent conductivity and wear resistance. Aluminum connectors are tin- or silver-plated to break down the insulating oxide layer on the aluminum surface and ensure a reliable electrical connection.
Short Answer: Our High-Voltage (HV) Insulation Series currently covers voltage levels up to 145kV (for 110kV/132kV grids), and we can custom-develop products for even higher voltages upon request.
Detailed Explanation: Our HV Insulation Series demonstrates our advanced technical capabilities, primarily serving the power transmission sector. We currently have commercialized product lines that are stably applied in systems with rated voltages of 72.5kV and 145kV. This includes 145kV disc insulators for GIS, 145kV composite hollow core insulators (with a silicone rubber housing) for outdoor circuit breakers and instrument transformers, and 145kV Resin Impregnated Paper (RIP) bushings for transformers. We possess advanced electric field simulation software and large-scale high-voltage testing facilities, enabling us to precisely design and verify the insulation structure of these HV products. We are also actively developing 252kV insulation solutions to meet market demands at higher voltage levels. If you have requirements exceeding our standard product range, our R&D team is ready to collaborate with you on a custom design.
Short Answer: Rising temperatures will reduce the mechanical strength and insulation resistance of an insulate tube or cylinder. Exceeding its thermal class rating (e.g., Class F) can cause permanent damage.
Detailed Explanation: Temperature is a key factor affecting the performance of epoxy glass-cloth laminated tubes and cylinders.
1)Mechanical Properties: As temperature increases, the epoxy resin matrix begins to soften, causing a decrease in the product’s bending and compressive strength. Our products typically have a Class F (155°C) or Class H (180°C) thermal rating, meaning they can operate safely at that temperature for their designated lifespan.
2)Electrical Properties: Higher temperatures lead to a decrease in the material’s volume resistivity and an increase in leakage current, weakening its insulating capability. This aging process is accelerated in high-temperature, high-humidity environments.
3)Thermal Aging: If operated for extended periods above its rated thermal class, the material will undergo irreversible chemical degradation, becoming brittle and prone to cracking, eventually losing its insulating and mechanical properties. Therefore, when selecting an insulate tube or cylinder, it is crucial to ensure its thermal class is higher than the maximum operating temperature of the equipment, with an adequate safety margin.
Short Answer: Our switchgear contact box features an integrated epoxy resin cast design with embedded high-elasticity tulip contacts, providing a compact structure, excellent heat dissipation, and high dynamic and thermal stability.
Detailed Explanation: Our switchgear contact box is engineered for superior performance.
1) Integrated Structure: We cast the contact fingers (tulip contacts) and the supporting insulation into a single piece using the APG process. This design eliminates numerous fasteners and separate insulators, resulting in a highly compact structure that saves valuable space inside the switchgear.
2) Optimized Tulip Contacts: The contact fingers are made from a high-elasticity, high-conductivity copper alloy. Their shape and number have been optimized through finite element analysis to ensure they provide uniform and stable contact pressure, effectively reducing contact resistance.
3) Excellent Heat Dissipation: The integrated epoxy housing efficiently conducts heat away from the contacts, increasing the product’s current-carrying capacity.
4) High Dynamic and Thermal Stability: The robust, monolithic structure can withstand the immense electrodynamic forces generated during a short circuit without deforming, ensuring safety and reliability under fault conditions.
Short Answer: The choice requires considering environmental regulations, equipment cost, technology maturity, and the complexity of gas handling. The eco-friendly series is the future, while the SF6 series is a mature technology.
Detailed Explanation: Choosing between SF6 and eco-friendly gas insulation solutions involves a trade-off among several factors:
1) Environmental Regulations: Many regions are already restricting the use of SF6. If your project is in an area with strict environmental laws or your company has carbon reduction targets, the eco-friendly gas series is the logical choice.
2) Initial Cost: Currently, due to newer technology and smaller production scales, switchgear using eco-friendly gases and its associated insulation parts often have a higher initial cost than traditional SF6 products.
3) Technology Maturity: SF6 technology has been in use for over 50 years and is proven to be highly reliable. While eco-friendly gas technologies are advancing rapidly, they have less long-term field experience, especially in ultra-high-voltage applications.
4) Gas Management: Handling and recycling SF6 gas requires special equipment and trained personnel to prevent leaks. In contrast, eco-friendly alternatives like clean air are simple to handle, simplifying installation, commissioning, and decommissioning processes. In summary, for new projects and environmentally conscious clients, we highly recommend the eco-friendly gas series solutions.
Short Answer: An insulate tube is hollow and typically smaller, used for rod insulation or as a coil former. An insulate cylinder generally refers to a larger diameter tube used as a major phase-to-phase or phase-to-ground barrier.
Detailed Explanation: While both are cylindrical insulators, their terminology and applications differ. An Insulating Tube usually refers to a smaller diameter, thinner-walled product. They are often made by filament winding glass fibers impregnated with epoxy resin. Common applications include serving as an insulating sleeve for operating rods in circuit breakers or as a winding former for coils in current transformers and reactors. The design focus is on dimensional accuracy and mechanical strength. An Insulating Cylinder typically refers to a larger diameter structure used for primary insulation. For example, in GIS or high-voltage circuit breakers, they serve as phase-to-phase barriers or as the main external housing and support for an interrupter chamber. They have high requirements for both electrical performance (withstand voltage, PD level) and mechanical strength and may feature reinforcing ribs or special flange designs.
Short Answer: We offer comprehensive customization, including adjustments to material formulation, modifications to size and structure, custom metal inserts, and performance optimization for specific operating conditions.
Detailed Explanation: We understand that standard products cannot meet every need. Therefore, we provide flexible customization solutions:
1) Material Customization: Our material engineers can adjust the epoxy resin formulation to meet special requirements, such as higher operating temperatures, enhanced weather resistance, or specific colors.
2) Structural & Dimensional Customization: We can manufacture non-standard sizes and shapes of insulation parts based on client drawings or 3D models, including modifying mounting holes or adding creepage sheds.
3) Custom Metal Inserts: We can embed various client-specified metal parts (e.g., nuts, flanges, conductive terminals) into the epoxy resin during the casting process to create a strong, integrated electromechanical assembly.
4) Performance Customization: For specific application environments, such as high altitude, heavy pollution, or high vibration, we can provide customized products with enhanced electrical margins or mechanical strength through simulation analysis and design optimization. Our team will work with you from concept design through to final testing.
Short Answer: Our epoxy resin insulating bushings are essentially maintenance-free in a normal indoor environment. They only require a visual inspection and cleaning during routine scheduled outages.
Detailed Explanation: Thanks to the excellent properties of epoxy resin, the maintenance for our indoor switchgear insulating bushings is extremely simple. In a normal, clean indoor operating environment, they are virtually maintenance-free. We recommend performing the following simple checks during planned annual or biennial power outages:
1) Visual Inspection: Visually check the bushing surface for any cracks, damage, or heavy accumulation of dust or contaminants. The epoxy surface is very robust and typically remains problem-free.
2) Cleaning: If the surface is dusty, wipe it with a dry, clean, lint-free cloth. For more stubborn dirt, a small amount of isopropyl alcohol can be used. Never use any corrosive chemical solvents.
3) Fastener Check: Check the bolts connecting the conductor and the mounting flange bolts for any signs of loosening. Beyond these simple steps, no preventive testing or special maintenance is required, significantly reducing our clients’ operational and maintenance costs.
Short Answer: We ensure a superior bond between the epoxy resin and metal inserts by sandblasting the metal parts, applying a special coupling agent, and optimizing the APG process parameters.
Detailed Explanation: The interface between epoxy resin and metal inserts can be a weak point in an insulation component, potentially leading to debonding or partial discharge. We take three key measures to guarantee a strong bond:
1) Physical Surface Preparation: Before casting, all metal inserts undergo sandblasting. This not only removes surface oxides and grease but also creates a rough surface profile, which dramatically increases the mechanical interlocking force with the resin.
2) Chemical Treatment: After sandblasting, we apply a thin layer of a silane coupling agent to the metal surface. One end of the coupling agent molecule forms a strong chemical bond with the metal oxide, while the other end reacts with the epoxy resin. This creates a chemical “bridge,” tightly linking the inorganic metal to the organic resin.
3) Process Optimization: During the APG injection process, we precisely control the mold preheating temperature and resin injection pressure to ensure the liquid resin fully “wets” the metal surface and eliminates any micro-voids at the interface, thereby achieving a perfect, void-free bond.
Short Answer: Our other insulation components, such as barrier plates and busbar supports, are fundamental to safety as they provide reliable phase-to-phase and phase-to-ground isolation, preventing electrical short circuits.
Detailed Explanation: In addition to core components like insulators and bushings, a switchgear cubicle requires numerous other insulation parts to create a complete and safe insulation system. While seemingly simple, these components are critical for safety.
1)Insulating Barriers/Plates: These are installed between live parts of different phases or between live parts and the earthed enclosure. They physically block the path of an electrical arc, increasing the switchgear’s insulation margin and safety.
2)Busbar Supports: These are used to fix and support the main busbars inside the cubicle. They must not only bear the weight of the busbars but also withstand the immense electrodynamic forces during a short circuit without failing.
3)Cable Clamps: Made of insulating material, these are used to securely fasten high-voltage cable terminations, ensuring they maintain a safe insulation distance from grounded metal parts. Together, these components form the “lines of defense” within the switchgear. The failure of any one of them could lead to a catastrophic equipment failure, which is why we apply the same stringent quality standards to them as we do to our core products.
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