I. Product Overview
The ZJ-35Q/145×320, 360, 380 series post insulators are epoxy resin cast insulators specifically designed for 35kV power systems. Manufactured using high-performance epoxy resin composite materials via an integral vacuum casting process, they offer excellent insulation properties, mechanical strength, and weather resistance. These insulators are widely used in power equipment such as high-voltage switchgear, ring main units (RMUs), and box-type substations to provide electrical insulation and mechanical support between live and grounded components, serving as a core insulation element in medium-voltage distribution systems.
II. Product Features
- Excellent Electrical Performance
- Rated voltage of 35kV, capable of withstanding a maximum system operating voltage of 40.5kV; features ample insulation margin and complies with national and industry standards such as GB/T 20840 and GB/T 11022;
- Utilizes a high-purity epoxy resin formulation offering low dielectric loss and high insulation resistance; partial discharge level ≤5pC (at 1.1Um/√3), ensuring no risk of insulation aging during long-term operation;
- Optimized shed structure with ample creepage distance effectively enhances resistance to pollution flashover and wet flashover, making it suitable for high-humidity and heavily polluted environments.
- High Mechanical Strength
- Monolithic cast molding eliminates internal air gaps and delamination defects; flexural, compressive, and torsional strengths far exceed those of traditional porcelain insulators;
- Rated bending failure load ≥8kN and rated tensile failure load ≥10kN; withstands mechanical stresses during transport, installation, and operation without risk of fracture;
- Integrated design of the base mount and main body ensures high connection strength and eliminates the risk of loosening after installation.
- Strong Environmental Adaptability
- Epoxy resin material offers excellent resistance to weather, UV radiation, ozone, and chemical corrosion, enabling long-term operation in harsh environments such as outdoor settings and areas with industrial pollution;
- Flame retardancy meets UL94 V-0 standards; self-extinguishing upon exposure to fire with no toxic smoke emission, complying with fire safety requirements for power equipment;
- Excellent high- and low-temperature performance; operates stably within a temperature range of -40°C to +85°C, adapting to climatic conditions across all regions.
- Structural and Manufacturing Advantages
- Sheds feature a large creepage distance and uniform diameter design; aesthetically pleasing, resistant to pollution accumulation, easy to clean, and low-maintenance;
- Vacuum casting process ensures a bubble-free, defect-free interior with excellent product consistency and high reliability;
- Fully sealed structure offers superior moisture and condensation resistance, suitable for indoor, outdoor, and semi-enclosed equipment applications.
III. Technical Parameters
- Key Electrical Parameters
| Parameter | Specification |
|---|---|
| Rated Voltage (Un) | 35 kV |
| Maximum System Voltage (Um) | 40.5 kV |
| Rated Lightning Impulse Withstand Voltage (Peak) | 185 kV |
| Rated Power-Frequency Withstand Voltage (RMS, 1 min) | 95 kV |
| Creepage Distance | ≥1050 mm (for 145 mm shed diameter specification) |
| Partial Discharge Level | ≤5 pC (at 1.1Um/√3) |
| Insulation Resistance | ≥1×10¹² Ω |
| Dielectric Dissipation Factor (tan δ) | ≤0.002 (20°C, 50 Hz) |
2.Mechanical Parameters
| Parameter | Specification |
|---|---|
| Rated Cantilever Failing Load | ≥8 kN |
| Rated Tensile Failing Load | ≥10 kN |
| Rated Compressive Failing Load | ≥20 kN |
| Shed Diameter (D) | 145 mm |
| Overall Height (H) | 320 mm / 360 mm / 380 mm (three specifications available) |
| Mounting Hole Specification | Compatible with M12/M16 standard bolts (customizable) |
| Weight | Approx. 3.2 kg (320 mm) / 3.6 kg (360 mm) / 3.8 kg (380 mm) |
3.Environmental and Material Parameters
| Parameter | Specification |
|---|---|
| Ambient Temperature Range | -40°C to +85°C |
| Altitude | ≤1000 m (high-altitude versions available on request) |
| Relative Humidity | Daily average ≤95%, monthly average ≤90% |
| Flame Retardancy Rating | UL94 V-0 |
| Main Body Material | Epoxy resin + glass fiber reinforced composite |
| Color | Standard red (other colors available on request) |
| Protection Class | IP67 |
4. Model Designation
| Code | Description |
|---|---|
| ZJ | Post insulator (epoxy resin cast type) |
| 35 | Rated voltage class 35 kV |
| Q | Fully insulated / heavy-duty construction |
| 145 | Maximum shed diameter 145 mm |
| 320/360/380 | Overall product height (mm) |
V. Scope of Application
- Applicable voltage levels: 35kV (40.5kV) AC power systems;
- Applicable equipment: 35kV high-voltage switchgear cabinets, armored metal-enclosed switchgear (e.g., KYN61), ring main units (RMU), box-type substations, gas-insulated switchgear (GIS/C-GIS), reactive power compensation devices, high-voltage busbar bridges, etc.;
- Applicable scenarios:
￮ Insulation support within high-voltage cabinets in indoor power distribution rooms and substations;
￮ Busbar insulation in outdoor box-type substations and switching stations;
￮ Power distribution systems for industrial enterprises and step-up station equipment for new energy power plants (photovoltaic, wind power);
￮ Power distribution equipment for special environments such as rail transit and mining operations.
VI. Operating Conditions
- Normal operating conditions
- Ambient temperature: -40°C to +85°C; daily temperature variation not exceeding 25°C;
- Altitude: Not exceeding 1000m (for altitudes above 1000m, insulation correction is required in accordance with GB/T 11022; products customized for high altitudes are available);
- Atmospheric conditions: Free from severe pollution, corrosive gases, and flammable/explosive media; relative humidity ≤95% (daily average) and ≤90% (monthly average); no condensation (for indoor use);
- Installation site: Free from severe vibration or impact; suitable for vertical or horizontal installation;
- Power frequency: 50Hz (60Hz available upon request).
- Special operating conditions (customization required)
- High-altitude areas (>1000m): Requires increased creepage distance and optimized insulation structure;
- Areas with high pollution levels (salt spray, chemical pollution): Requires increased creepage distance and application of anti-pollution coatings;
- Extreme temperature environments (<-40°C or >+85°C): Requires customized epoxy resin formulations;
- Scenarios with strong vibration or impact: Requires enhanced mechanical strength design. VII. Installation and Maintenance
- Installation Requirements
- Inspect the product’s appearance before installation: ensure there are no cracks, damage, air bubbles, or deformation, and that the sheds are intact;
- Use standard bolts for fastening and control the torque between 25 and 35 N·m to avoid damaging the insulator through excessive force;
- Keep the insulator clean during installation; prevent oil, grease, or impurities from adhering to the surface, as this could impair insulation performance;
- Can be installed vertically, horizontally, or at an angle; there are no restrictions on installation orientation.
- Maintenance Requirements
- Regularly clean the shed surfaces to remove accumulated dirt and dust, ensuring insulation performance is maintained;
- Check the tightness of installation bolts to prevent loosening;
- Conduct periodic preventive insulation tests to monitor parameters such as partial discharge and insulation resistance;
- Immediately replace the product if cracks, damage, or deformation occur; do not continue using it.
VIII. Applicable Standards
- GB/T 8287.1-2019 “Indoor and outdoor post insulators for systems with nominal voltages greater than 1000 V – Part 1: Ceramic or glass insulators”
- GB/T 20840.1-2018 “Instrument transformers – Part 1: General requirements”
- GB/T 11022-2011 “Common specifications for high-voltage switchgear and controlgear standards”
- DL/T 486-2010 “High-voltage AC disconnectors and earthing switches”
- IEC 60660 “Indoor and outdoor post insulators”
IX. Precautions
- Avoid collisions or drops during product transport and handling to prevent damage to the sheds;
- Store in a dry, well-ventilated environment; avoid direct sunlight, high temperatures, and humidity;
- Do not drill holes or cut the product surface; unauthorized modification is prohibited;
- If the product exceeds its service life (typically 20 years), periodic testing and timely replacement are recommended;
- Installation and maintenance must be performed by qualified electrical personnel in compliance with electrical safety regulations.
X.Selection Guide
| Model | Overall Height | Recommended Application |
|---|---|---|
| ZJ-35Q/145×320 | 320 mm | Compact 35 kV switchgear; applications with reduced busbar spacing |
| ZJ-35Q/145×360 | 360 mm | Standard 35 kV high-voltage switchgear; conventional busbar support |
| ZJ-35Q/145×380 | 380 mm | High-altitude or heavily polluted locations; large-current busbar support applications |
