Knowledge of Bus Connectors

The busbar connectors of medium-voltage switch cabinets (ring network cabinets / gas-filled cabinets) are key components used to achieve electrical connection between adjacent switch cabinet units. Depending on the insulation medium and structural form, they are mainly divided into two categories: fully insulated plug-in type busbar connection systems and dedicated busbar connectors for gas-filled cabinets.

Application scenario

Ring network power supply unit: Connects incoming cabinet, outgoing cabinet, metering cabinet, etc.

Compact design of substation: For the connection of high-voltage rooms in box-type substations.

Data center / Rail transit: Power distribution system with high reliability requirements.

I. Fully Insulated Plug-in Type Busbar Connection System (Suitable for Solid Insulation Ring Network Cabinets / Environmental Protection Cabinets)

This type of product uses silicone rubber or epoxy resin as the main insulation to achieve fully insulated and fully sealed connections between cabinet bodies, without the need for inflation.

1. Product Structure Composition

Connector Head: Such as T-head, +-head, or I-head. Inside, there are conductive contacts or梅花 contacts for connecting the cabinet bushings and the busbar conductors.

Shielded Busbar： The conductor (usually a copper tube) is wrapped with a silicone rubber insulation layer， and the outermost layer is a semiconductive shielding layer that is reliably grounded to ensure that the enclosure is touchable.

2. Key Features

Fully insulated and fully shielded: The surface potential is zero, and the protection level can reach IP67. It can operate in water immersion.

Modular expansion: Through the combination of T-junctions and cross-junctions, cabinet expansion in any direction can be achieved.

Installation is convenient: Plug-and-play structure, no need for special tools, and the on-site cabinet assembly is fast.

Maintenance-free: Silicone rubber material has excellent hydrophobicity and aging resistance, with a long service life.

II. Special Busbar Connectors for Gas-Charged Cabinets (Suitable for SF6/Environmental Gas Insulated Cabinets)

These products are usually installed between gas compartments and serve as the connecting element of the gas box, requiring extremely high gas tightness and mechanical strength.

1. Product Structure

Conductor: Utilize contacts or tab contact structures to ensure low contact resistance and good self-centering capability.

Insulation Support： Epoxy resin castings, serving as the support and main insulation for the conductors.

Sealing Structure: Typically employ O-rings or welded corrugated tubes to ensure the sealing isolation between gas compartments.

Shield Design： Incorporate uniform pressure covers or external shielding covers to optimize the electric field distribution.

2. Key Features

Air Tightness: The annual leakage rate is typically required to be ≤ 0.1% or lower.

Self-Compensation: It has the ability to compensate axially and radially to absorb the manufacturing and installation errors of the cabinet.

Three-Position Integration: Some designs integrate the isolation/grounding functions within the connector.