Product Overview
The TG3-24Q/180×180×280 Wall Bushing is a core insulating component designed for 24 kV indoor high-voltage switchgear. It is manufactured from high-performance epoxy resin using an integrated APG (Automatic Pressure Gelation) process.
The product is mainly used to provide electrical insulation and mechanical support where high-voltage conductors pass through switchgear enclosures or walls, helping ensure the safe and stable operation of the power system.
Technical Specifications
| Parameter | Specification |
|---|---|
| Rated Voltage | 24 kV |
| Mounting Dimensions | 180 × 180 mm |
| Overall Height | 280 mm |
| Material | Epoxy resin, reddish brown |
| Power-Frequency Withstand Voltage | 65 kV for 1 minute |
| Lightning Impulse Withstand Voltage | 125 kV |
| Partial Discharge | ≤10 pC at 26.4 kV; ≤2 pC at 21 kV |
| Creepage Distance | ≥480 mm |
| Glass Transition Temperature | ≥105°C |
| Optional Rated Current | 2,000–4,000 A |
| Flame-Retardant Rating | Complies with UL94 V-0 |
| Product Certification | ISO 9001 and others |
Product Features
Excellent Insulation Performance
The epoxy resin body provides high dielectric strength. Combined with the shed-profile structure, it effectively increases the creepage distance and improves resistance to pollution flashover.
The product maintains stable insulation performance at high voltage levels and helps prevent leakage current and electrical breakdown.
Reliable Mechanical Strength
The one-piece moulded structure provides good impact and bending resistance. It can withstand electrodynamic forces caused by busbar short circuits as well as mechanical stresses during installation and operation, ensuring long-term structural stability.
Weather and Ageing Resistance
The material offers resistance to high and low temperatures, moisture, corrosion, and ageing. It is suitable for complex indoor operating environments and provides a long service life with low maintenance requirements.
Optimized Electric Field Distribution
The internal structure provides uniform electric field distribution, effectively suppressing partial discharge and reducing the risk of corona discharge and insulation ageing. This improves the operational safety of the complete equipment.
Convenient Installation
The square flange is designed to match compatible switchgear structures accurately. It provides convenient positioning during installation and reliable sealing performance.
Applications
- Suitable for 24 kV indoor withdrawable high-voltage switchgear, including the KYN28-24 series, ring main units, and other high-voltage electrical equipment.
- Used as a busbar wall-passage insulating component.
- Suitable for power plants, substations, industrial power distribution systems, and other applications requiring insulation between high-voltage conductors and grounded switchgear enclosures or walls.
- Intended for indoor use only.
- Not suitable for outdoor, high-altitude, or heavily polluted environments unless a customized high-altitude or pollution-resistant version is selected.
Operating Conditions
Normal Operating Environment
- Installation altitude: ≤1,000 m. Derating or a high-altitude version is required above 1,000 m.
- Ambient temperature: -5°C to +40°C.
- The product can withstand a short-term ambient temperature of up to +60°C. Above +40°C, the rated current should be reduced by 1.8% for each additional degree Celsius.
- Relative humidity: ≤85% at 20°C.
- The operating environment should be free from condensation and frost.
- The installation location should be free from corrosive gases, vapours, and dust.
- Flammable or explosive substances are not permitted.
- Severe vibration and mechanical impact should be avoided.
Adjustments for Special Environments
- When the ambient temperature is below +40°C, the rated current may be increased by 0.5% for each degree Celsius, with a maximum total increase of 20%.
- For high-altitude locations above 1,000 m or heavily polluted environments, a corresponding weather-resistant or pollution-resistant version should be selected.
- Insulation performance and current-carrying capacity must be recalculated for special operating conditions.
Installation and Maintenance Precautions
- Before installation, inspect the product to ensure that there are no cracks, damage, bubbles, or other visible defects. Remove dust and oil from the insulating surface.
- The flange must fit closely against the switchgear enclosure or wall. Tighten all bolts evenly to prevent localized mechanical stress that could cause insulation cracking.
- When the busbar passes through the bushing, ensure that the conductor is centred and does not contact the inner wall, preventing localized electric field concentration.
- Conduct regular inspections for electrical tracking marks, cracks, ageing, or discoloration. Remove accumulated dust and carry out partial discharge testing when necessary.
- Do not drill, cut, or otherwise machine the product surface, as this may damage the insulating structure.
Model Designation
- TG3: Wall bushing series code
- 24: Rated voltage of 24 kV
- Q: Indoor type; W indicates outdoor type
- 180×180: Mounting flange dimensions in millimetres
- 280: Overall product height in millimetres
