Function of Low-voltage busbar compartment partition

A low-voltage busbar compartment partition is an insulating and supporting device that separates busbars from electrical apparatuses while providing structural support and electrodynamic stress management in switchboards. Function and DesignLow-voltage switchboards use parallel metallic busbars to distribute power across phases, connecting to devices such as circuit breakers, switches, and control instruments. Compartment partitions serve to electrically insulate busbars from each other and from apparatus compartments, while also supporting the busbars mechanically and transferring electrodynamic stresses to the cabinet frame.

These partitions are typically made from insulating materials and have a rectangular body with surfaces designed to couple with busbars and electrical apparatuses.

Structural Features

Retaining Surfaces: Pairs of retaining teeth or surfaces create mechanical friction to hold busbars securely, accommodating different busbar dimensions for flexibility. Stacking Capability: Partitions can be vertically stacked to support multiple busbars along the cabinet height. Connection Openings: Openings allow electrical connections between busbars and apparatuses without compromising insulation.

Horizontal and Vertical Support: Partitions can act as a “roof” or “floor” for busbars, providing support in both directions.

Compliance and Safety

According to IEC 61439, low-voltage switchgear must meet requirements for temperature rise, short-circuit withstand strength, dielectric properties, and personnel protection. Compartment partitions contribute to Forms of Internal Separation, ranging from minimal separation to full segregation of busbars, functional units, and terminals (e.g., Form 4b), enhancing arc fault containment and safety. Proper partitioning ensures that busbars can withstand short-circuit and internal arc conditions while maintaining insulation and structural integrity.

Benefits

Reduces the number of components needed for busbar assembly. Maintains required insulation and separation between busbars and apparatus compartments. Provides reliable support under electrodynamic stresses, including short-circuit events.

Flexible design accommodates different busbar sizes and configurations. Simplifies assembly and maintenance of low-voltage switchboards. In summary, low-voltage busbar compartment partitions are critical components in switchboard design, ensuring electrical safety, mechanical stability, and compliance with modern standards while facilitating efficient installation and maintenance.