WCTH-40.5-1250-660P2 (Two-way) with Shielded Contact Box

I. Product Overview

The WCTH-40.5-1250-660P2 is a two-way 40.5kV shielded contact box , molded using epoxy resin APG pressure gel technology. It is mainly used in KYN61-40.5 and other handcart-type high-voltage switchgear to achieve insulation isolation, electric field shielding, and electrical connection transition between the circuit breaker and the busbar/cable, ensuring the insulation safety and operational reliability of the switchgear under high-voltage conditions.

The product features a left-right cable outlet structure and an internal shielding layer that effectively uniformizes the electric field and suppresses partial discharge, making it suitable for 1250A rated current applications.

II. Technical Parameters

III. Product Characteristics

1. Electric field shielding design : The built-in conductive grounding shielding layer can uniformly distribute the internal electric field, significantly reduce partial discharge, suppress corona and surface discharge, and improve insulation reliability.
2. High-performance insulating material : It is molded using epoxy resin APG pressure gelation process, with high mechanical strength, aging resistance, arc resistance, and glass transition temperature ≥105℃, which can adapt to long-term high-temperature operation conditions.
3. Two-way left and right outgoing cable structure : adaptable to the left and right outgoing busbar/cable requirements of cabinet types such as KYN61-40.5, with strong installation compatibility and flexible wiring.
4. Low partial discharge characteristics : Optimized insulation structure and shielding design keep partial discharge at an extremely low level, meeting the requirements of IEC and domestic high-voltage equipment standards.
5. Long creepage distance : Creepage distance ≥ 810 mm, which can meet the insulation requirements of pollution level II and above, and improve the anti-pollution flashover capability.
6. Integrated molding : No splicing structure, good sealing performance, effectively prevents dust and moisture intrusion, and ensures stable internal insulation performance.

IV. Scope of Application

• Suitable for 35kV/40.5kV indoor handcart-type high-voltage switchgear (such as KYN61-40.5 type), as an insulating connection and transition element between circuit breaker and busbar and cable.
• It can be used with ZN95-40.5, 3AV3 and other series 40.5kV vacuum circuit breakers.
• Widely used in medium and high voltage power transmission and distribution scenarios such as substations, industrial power distribution, and urban power grids, ensuring safe circuit switching and insulation isolation.

V. Usage Conditions

1. Environmental conditions

• Altitude: ≤1000 m (high-altitude type can be customized to ≤4000 m)
• Ambient temperature: -10℃ ~ +40℃, daily average temperature ≤35℃
• Relative humidity: daily average ≤95%, monthly average ≤90% (at 20℃), no condensation.
• Filth level: Level II and below (higher levels require special customization)
• Installation location: Free from severely corrosive gases, vapors, dust, explosive or flammable media, and free from frequent vibration and impact.

2. Electrical operating conditions

• Rated current: not exceeding 1250 A during long-term operation; temperature rise at the outgoing terminal ≤ 65 K (relative to ambient temperature).
• Short-circuit withstand: Capable of withstanding the rated short-time withstand current (e.g., 25 kA/4 s) and peak withstand current surge of the corresponding switchgear.
• Insulation coordination: Complies with the insulation requirements for 40.5kV equipment in standards such as GB/T 311 and IEC 60071.

VI. Installation and Maintenance Precautions

1. Before installation, check that the product has no cracks, bubbles, or damage, and that the shielding layer is reliably grounded.
2. Strictly follow the dimensions in the drawings for positioning and installation to ensure the accuracy of the fit with the circuit breaker contacts and busbars/cables, and avoid mechanical stress damage to the insulation components.
3. The shielding layer must be reliably grounded; otherwise, it will lose its electric field shielding effect and pose a risk of partial discharge.
4. Regular inspections during operation: observe the surface for traces of electric current, discoloration or cracks, measure the amount of partial discharge, and handle any abnormalities promptly.
5. Avoid prolonged exposure to humid, dusty, or corrosive environments, and install protective measures if necessary.

VII. Implementation Standards

• GB/T 11022 Common Technical Requirements for High Voltage Switchgear and Controlgear Standards
• GB/T 311 Insulation Coordination of High Voltage Transmission and Transformation Equipment
• IEC 60694 Common Clauses for Standards on High Voltage Switchgear and Controlgear
• Enterprise Technical Specification Q/WCTH-202X 《Technical Conditions for 40.5kV Series Contact Boxes》

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