Product Overview
The CH3-24kV/250 3150-4000A withdrawable switchgear contact box (shielded version available) is manufactured using epoxy resin APG (Automatic Pressure Gelation) process molding. It is a heavy-current insulating connection device designed exclusively for 24kV-class draw-out withdrawable switchgear. The unit is primarily applied in 24kV-class draw-out withdrawable switchgear, providing insulation isolation, connection transition, and shielding protection. It delivers effective insulating protection for internal contacts within the switchgear, is suited for power systems requiring extra-large current transmission, and ensures the safe and stable operation of electrical power systems.
Application Scope
This contact box is applicable to 24kV-class draw-out withdrawable switchgear and is commonly found in large-scale power distribution systems, industrial substations, distribution systems for large mining and industrial enterprises, large hydropower stations, power dispatch centers, and other electrical facilities requiring extra-large current transmission. It serves as an insulating protection and connection transition component for internal switchgear contacts, providing reliable insulation for the switching and isolation of high-voltage circuits. It meets the demands of extra-large current power transmission, and the shielded variant effectively reduces electromagnetic interference.
Service Conditions
The installation altitude must not exceed 1,000 m.
Ambient air temperature: -5°C to +40°C; relative humidity at 20°C must not exceed 85%.
The installation site must be free of gases, vapors, dust, or other explosive and corrosive media that could severely impair the insulating performance of the contact box.
The unit must be installed in locations free from severe vibration and mechanical shock to ensure structural integrity.
Intended for indoor installation; compatible with large-format busbar mounting configurations.
Product Features
Superior insulating performance: Formed using the epoxy resin APG process, the unit provides excellent insulation, effectively isolating high-voltage circuits, preventing leakage and short-circuit risks, and withstanding high-voltage impulse.
Electromagnetic shielding: Available with an integrated shielding structure that effectively reduces electromagnetic interference and ensures stable electrical signal transmission.
Extra-large current capacity: Rated current up to 4,000 A, meeting the extra-large current transmission requirements of large-scale power facilities while minimizing resistive heating losses.
Robust and durable construction: One-piece molded structure provides high mechanical strength, capable of withstanding both mechanical and electrical stress within the switchgear enclosure, resulting in a long service life.
Effective temperature rise control: Under continuous rated-current operating conditions, the temperature rise at the output terminal does not exceed 65°C, ensuring operational safety and preventing faults caused by excessive heat.
Ease of installation: Standardized mounting dimensions compatible with conventional 24kV withdrawable switchgear, facilitating on-site installation and replacement.
Corrosion and oxidation resistance: The epoxy resin material offers excellent resistance to corrosion and oxidation, suitable for a variety of complex electrical environments.
Superior surface finish: Smooth, burr-free surface for convenient installation, with good flame-retardant and wear-resistant characteristics.
Technical Parameters
| Parameter | Specification |
|---|---|
| Rated Voltage | 24 kV |
| Rated Current | 3,150 A – 4,000 A |
| Power Frequency Withstand Voltage | 55 kV / 1 min |
| Lightning Impulse Withstand Voltage | 125 kV |
| Glass Transition Temperature | ≥ 105°C |
| Creepage Distance | > 520 mm |
| Mounting Center Distance | 206 mm |
| Temperature Rise Limit | Terminal temperature rise not exceeding 65°C at rated current |
| Material | Epoxy resin housing + copper alloy contacts + shielding structure |
| Protection Rating | IP67 |
