Product Overview
The CHZ3-20kV/250 contact box is manufactured using an epoxy resin APG (Automatic Pressure Gelation) process with a pressure gel molding structure. It is a dedicated insulating connection device for 20 kV class draw-out switchgear, primarily applied in 20 kV class centrally-mounted draw-out switchgear cabinets. It serves the functions of insulating isolation and transitional connection, providing effective insulation protection for internal contacts within the switchgear. The device is suited for high-current power transmission applications and ensures the safe and stable operation of the power system.
Application Scope
This contact box is applicable to 20 kV class centrally-mounted draw-out switchgear cabinets. It is commonly used in large-scale power distribution systems, industrial substations, high-rise building distribution rooms, and large mining and industrial enterprise power distribution systems requiring high-current transmission. It serves as an insulating protection and transitional connection component for internal contacts within the switchgear, providing reliable insulation assurance for the switching and isolation of high-voltage circuits, and meeting the demands of high-current power transmission.
Operating Conditions
Installation altitude shall not exceed 1000 m above sea level.
Ambient air temperature: -10°C to +40°C; relative humidity shall not exceed 95% at 25°C.
The installation site shall be free of gases, vapors, dust, and other explosive or corrosive media that may significantly impair the insulation performance of the contact box.
The device shall 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
Excellent Insulation Performance: Formed using the epoxy resin APG process, the contact box exhibits superior insulation properties, effectively isolating high-voltage circuits and preventing leakage and short-circuit risks while withstanding high-voltage impulses.
High-Current Handling Capability: Rated current up to 4000 A, meeting the high-current transmission requirements of large power facilities while minimizing resistive heating losses.
Robust and Durable Structure: The monolithic molded construction provides high mechanical strength, capable of withstanding both mechanical and electrical stresses within the switchgear enclosure, resulting in an extended service life.
Effective Temperature Rise Control: Under continuous rated current operation, the temperature rise at the outlet terminal does not exceed 65°C, ensuring safe equipment operation and preventing failures caused by excessive thermal buildup.
Ease of Installation: Standardized mounting dimensions compatible with conventional 20 kV centrally-mounted switchgear, facilitating on-site installation and replacement.
Corrosion and Oxidation Resistance: The epoxy resin material offers excellent resistance to corrosion and oxidation, enabling reliable performance across a variety of complex electrical environments.
Superior Surface Finish: Smooth, burr-free surface finish ensures convenient installation, with good flame-retardant and wear-resistant characteristics.
Technical Parameters
| Parameter | Specification |
|---|---|
| Rated Voltage | 20 kV |
| Rated Current | 2000 A – 4000 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 Dimensions | Compatible with 20 kV centrally-mounted switchgear installation specifications |
| Temperature Rise Limit | Terminal temperature rise not exceeding 65°C at rated current |
| Materials | Epoxy resin housing + copper alloy contacts |
