24kV Integrated Insulator
Product Overview
The 24kV integrated insulator is a core insulating component specifically designed for 24kV medium-voltage switchgear and related power equipment. Manufactured using a monolithic molding process, it combines electrical insulation, mechanical support, and isolation/protection functions. It is widely used in indoor medium-voltage power distribution systems and serves as a critical insulating component ensuring the safe and stable operation of power equipment.
Product Features
Excellent Electrical Performance
Rated insulation voltage is matched to 24kV medium-voltage systems with high dielectric strength, capable of withstanding the system rated voltage, lightning impulse overvoltage, and switching overvoltage, effectively preventing surface flashover, breakdown, and other insulation failures.
Manufactured from high-quality epoxy resin (or epoxy glass fiber reinforced plastic), the material exhibits low dielectric loss and high insulation resistance, with no insulation aging or performance degradation during long-term operation, meeting the requirements of GB/T 1408.1 and other national standards.
The shed profile design optimizes electric field distribution, increases creepage distance, and effectively suppresses the risk of insulation failure in contaminated or humid environments.
Reliable Mechanical Performance
The monolithic integrated structure design provides high mechanical strength and excellent impact resistance, capable of withstanding the mechanical and installation stresses imposed by busbars and contacts, with no risk of cracking or deformation.
Excellent vibration and seismic resistance ensures the mechanical stability required for long-term operation of power equipment and accommodates the complex installation conditions within switchgear enclosures.
Brass inserts are embedded at the top with high-precision threading, providing a secure connection capable of sustaining long-term busbar clamping forces without loosening or pullout.
Strong Environmental Adaptability
The material offers weathering resistance and corrosion resistance, capable of withstanding indoor temperature and humidity variations and mildly contaminated environments without cracking, chalking, or aging.
Excellent flame retardancy compliant with UL94 V-0 flame retardant standard — the material does not ignite or sustain combustion when exposed to an open flame, enhancing fire safety of the equipment.
Moisture resistance, mold resistance, and salt spray resistance meet applicable standards, making the product suitable for indoor power distribution environments across different regions.
Structural and Process Advantages
The integrated monolithic design reduces assembly steps, improves installation efficiency, and eliminates the sealing and insulation risks associated with multi-piece structures.
Vacuum epoxy casting process ensures the product is free of voids and defects, with uniform and consistent internal insulation performance and high quality stability.
The open-bottom structure accommodates the installation requirements of switchgear busbar compartments and contact boxes, offering strong compatibility with enclosures and busbars for easy installation.
Core Technical Parameters
Note: The above parameters are for standard model specifications. Custom parameters (e.g., higher withstand current, special creepage distance, etc.) are available upon customer request.
Application Scope
Applicable Scenarios
24kV indoor metal-clad withdrawable switchgear (KYN28A-24 and similar models)
24kV indoor fixed-mounted switchgear and ring main units
Busbar support and contact insulation isolation for 24kV medium-voltage distribution equipment
Internal insulating components for 24kV compact substations and switching stations
Insulation support and isolation for other 24kV medium-voltage power equipment
Applicable Systems
Three-phase AC 50Hz, 24kV medium-voltage power distribution systems
Systems with unearthed neutral, arc suppression coil (Petersen coil) earthed neutral, or resistance-earthed neutral
Power equipment in indoor power distribution environments
Operating Conditions
Normal Operating Conditions
Altitude: ≤1000m (high-altitude customization available; insulation parameters corrected per GB/T 11022)
Ambient temperature: -5°C ~ +40°C (daily average temperature ≤35°C)
Relative humidity: daily average relative humidity ≤95%, monthly average relative humidity ≤90%, no condensation
Environmental conditions: indoor installation, no severe contamination, no corrosive gases, no flammable or explosive media, no intense vibration or shock
Mounting orientation: vertical installation, tilt angle ≤5°
Special Operating Conditions (Customization Required)
High-altitude environments (altitude >1000m): insulation parameters must be corrected for altitude with increased creepage distance and dielectric strength
High/low temperature environments (outside the -5°C ~ +40°C range): custom materials for high/low temperature resistance
Heavily contaminated environments: increased creepage distance with anti-pollution shed profile design
Special vibration/shock environments: enhanced mechanical strength design
Installation and Maintenance Requirements
Installation Requirements
Inspect the product appearance before installation: no cracks, no voids, no damage, no loose inserts
Install strictly according to the switchgear assembly drawings to ensure vertical mounting with a tilt angle not exceeding 5°
When connecting busbars, tighten insert bolts to the specified torque to avoid cracking the insulator due to excessive force
Avoid striking or knocking the insulator during installation to prevent insulation damage
Clean surface dust and foreign matter after installation to ensure the insulating surface is clean
Maintenance Requirements
Regular inspection: check the insulator surface for contamination, cracks, and discharge marks, and check inserts for looseness
Cleaning and maintenance: wipe the surface with a dry cloth; the use of corrosive cleaning agents is strictly prohibited
Insulation testing: conduct periodic insulation resistance and withstand voltage tests to verify that insulation performance meets requirements
Replacement criteria: if cracks, puncture, or severe contamination that cannot be cleaned is found, replace the product immediately
Applicable Standards
GB/T 1408.1 — Methods of Test for Electric Strength of Insulating Materials — Part 1: Tests at Power Frequencies
GB/T 11022 — Common Specifications for High-Voltage Switchgear and Controlgear Standards
GB/T 4109 — Insulating Bushings for Alternating Voltages above 1000V
IEC 60660 — Insulators for High-Voltage Switchgear and Controlgear
JB/T 10685 — Insulating Parts for High-Voltage AC Switchgear
Precautions
This product is intended exclusively for indoor 24kV medium-voltage systems; operation beyond rated voltage or specified conditions is strictly prohibited
Installation and maintenance must be performed by qualified electrical personnel in strict compliance with electrical safety regulations
During transport and storage, avoid impact, moisture, and exposure to high temperatures; the storage environment must be dry and well-ventilated
If the product shows visible damage or fails to meet insulation performance requirements, it must not be put into service
For customized products, the bilateral technical agreement shall prevail; parameters in this manual are for reference for standard models only
Document Notes
This manual is the standard product technical manual for the 24kV integrated insulator. Parameters and content may be adjusted according to the customer’s specific model and customization requirements. All technical specifications are subject to the product factory inspection report.
Appendix: Product Outline Drawing
| Parameter Category | Technical Specification | Remarks |
|---|---|---|
| Rated Voltage | 24kV | Matched to 24kV medium-voltage distribution systems |
| Rated Frequency | 50Hz | Compliant with domestic power frequency standard |
| Rated Lightning Impulse Withstand Voltage | 125kV (peak) | Phase-to-earth / phase-to-phase |
| Rated Power Frequency Withstand Voltage | 42kV (1 min) | Phase-to-earth / phase-to-phase |
| Creepage Distance | ≥450mm | Meets pollution severity class II and above |
| Insulation Resistance | ≥1×10¹²Ω | Under normal conditions |
| Dielectric Dissipation Factor (tan δ) | ≤0.005 | At power frequency |
| Rated Short-Time Withstand Current | 25kA/4s (customizable) | Matched to switchgear short-circuit current requirements |
| Rated Peak Withstand Current | 63kA (customizable) | | |
| Flame Retardancy Class | UL94 V-0 | | |
| Operating Temperature Range | -40°C ~ +85°C | Indoor environment |
| Relative Humidity | ≤95% (at 25°C) | No condensation |
| Material | Epoxy Resin (EP) / Epoxy Glass Fiber Reinforced Plastic | Customizable |
| Insert Material | Brass (tin-plated or silver-plated optional) | | |
| Protection Degree | IP20 | Suitable for indoor switchgear |
