Busbar Compression Assembly for Busway Thermal and Structural Integrity
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Solution Overview
Problem
Conventional busway power distribution systems face issues with inadvertent gaps between surge clamps and the housing, leading to deformation and thermal inefficiency during short circuit events, due to rigid fastening methods that do not apply compressive force to the busbar stack, causing stress and impaired heat dissipation.
Innovation Solution
The introduction of a busbar compression assembly that applies a variable compressive force to the busbar stack using threaded fasteners and compression nuts, ensuring proper alignment and contact between the busbars and the housing, thereby eliminating gaps and enhancing thermal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If surge clamps are rigidly fastened to duct sides using conventional methods, then the assembly is simple to manufacture, but gaps between surge clamps and housing occur due to manufacturing tolerances, leading to poor contact with busbars
Solution Approach 1:
The clamp assembly incorporates a movable clamp body that can shift position relative to the fixed mounting structure. This dynamic element allows the clamp to self-adjust and eliminate gaps caused by manufacturing tolerances, ensuring consistent contact with the busbar while maintaining a relatively simple overall assembly design
Solution Approach 2:
The system allows for adjustment of the clamp position parameter along the longitudinal axis. By enabling positional variation, the assembly can compensate for manufacturing variations in duct side dimensions and busbar positioning, achieving precise contact without requiring extremely tight manufacturing tolerances across all components
2Reliability
If surge clamps are rigidly fastened without compression, then the assembly structure is simple, but busbars can separate and deform during short circuit events, compromising system reliability
Solution Approach 1:
The clamp assembly pre-compresses the busbar stack against the duct housing before any short circuit event occurs. This preliminary compressive force ensures that the busbars are held firmly in position and cannot separate or deform during subsequent short circuit events, while the compression mechanism itself remains relatively simple in design
Solution Approach 2:
The system applies a preliminary compressive force that counteracts the magnetic repulsion forces that will arise during a short circuit. By pre-establishing this opposing force, the busbars are prevented from separating or deforming when the short circuit occurs, enhancing system reliability without requiring a complex active control system
3Temperature
If gaps exist between busbars and housing, then assembly is easier with fewer constraints, but thermal dissipation is impaired due to air pockets acting as thermal insulators
Solution Approach 1:
The clamp assembly pre-compresses the busbar stack against the duct housing to eliminate gaps and air pockets before the system begins operation. This preliminary action ensures optimal thermal contact between components, maximizing heat dissipation efficiency while maintaining a straightforward assembly process that does not require additional thermal interface materials or complex alignment procedures
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution increases the short-circuit integrity of the busway system, improves thermal efficiency by reducing air pockets, and allows for cost savings by minimizing conductor material usage, while maintaining the structural integrity of the busway components.
Implementation Method 1
Rotation of the bolt effectuates movement of the compression nut in a first direction. The movement of the compression nut, in turn, applies a 'nut' force on the surge clamp in a second direction. This force moves the surge clamp in a third direction whereby the surge clamp applies a compressive force to the stack of busbars.
Implementation Method 2
Each layer of air that exists between the individual busbars or between the busbars and the housing provides a layer of thermal resistance that is detrimental to heat being dissipated from the busbars to the surrounding environment. Utilizing some of the teachings disclosed herein, the busbar stack is compressed such that there are fewer and smaller intermittent layers of air and, thus, less thermal resistance in the system.
Data Source
AI summary
Electrical busway assemblies and methods and devices for applying compressive forces to a busbar stack in an electrical busway assembly are disclosed herein. Electrical busway assemblies for distributing electricity are presented. The busway assembly includes a stack of electrically conductive busbars with one or more duct sides each disposed on a respective side of the busbar stack. Optionally, a duct top and duct bottom can be placed on the stack top and stack bottom, respectively. A surge clamp engages the stack top or stack bottom. A bolt attaches the surge clamp to each duct side. A compression nut threadably engages each bolt. Rotation of a bolt moves the corresponding compression nut, which acts to move the surge clamp along a path that is oblique with the path of the compression nut. The surge clamp, when moved by the compression nut(s), acts to apply a compressive force to the busbar stack.