Four-Pole Plugging Assembly for Live Switchgear Unit Replacement

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Solution Overview

Problem

Low-voltage switchgear manufacturers face challenges in making interconnections between functional units, busbars, and terminals for external cables due to high packing density and limited space, while maintaining safety and minimizing power supply interruptions during maintenance or repairs.

Innovation Solution

A plugging assembly with a male and female plug system that allows for side-access or rear-access connections, featuring 'U' shaped spring-loaded clips for reliable electrical contact and improved cable protection, enabling easy removal and replacement of functional units without disconnecting external cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high form of internal separation (Form 3 or 4) is achieved to protect equipment and personnel, then safety and protection are improved, but interconnection between functional units, busbars and terminals becomes difficult

Engineering Contradiction:
Improveprotection of equipment and personnelVSAvoidinterconnection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention divides the connection system into separate male and female plugs with distinct functions. The male plug connects to the functional unit while the female plug remains in the switchgear, allowing separation of connection and protection functions. This segmentation enables easy interconnection while maintaining internal separation barriers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The plugging assembly acts as an intermediary component that bridges the gap between functional units and the switchgear infrastructure. It provides a standardized interface that simplifies interconnection while respecting the internal separation requirements, making the complex connection process manageable through a dedicated mediating component.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If functional units are made removable for easy maintenance, then ease of operation is improved, but power supply interruption occurs during removal

Engineering Contradiction:
Improveremovability of functional unitVSAvoidpower supply interruption time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The connection system is segmented into removable male plug (with functional unit) and fixed female plug (in switchgear). This allows the functional unit to be removed by simply disconnecting the male plug, while the female plug remains connected to maintain power supply to other units, eliminating the need to interrupt power for maintenance operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The female plug remains permanently connected to the switchgear infrastructure, ensuring continuous power supply and connection capability. When a functional unit is removed, the female plug is already in position to immediately connect to a replacement unit, maintaining continuous operational capability without interruption to the overall system.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If packing density of equipment is increased to save space, then productivity is improved, but difficulty of making interconnections increases

Engineering Contradiction:
Improvepacking density of equipmentVSAvoiddifficulty of interconnection
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The plugging assembly segments the connection function into standardized male and female components that can be densely packed. The compact design of the plugs allows them to fit into tight spaces while maintaining reliable electrical connections, enabling high equipment density without proportionally increasing connection complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the physical parameters of the connection components by using spring-loaded clips with specific dimensional characteristics. These clips are designed with optimized dimensions and spring forces that enable reliable connection in compact spaces, allowing high packing density while maintaining ease of interconnection through standardized parameters.

Inventive Principle:
Principle #35Parameter changes

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

The solution increases the number of cables per phase, allowing for higher operating currents and enabling functional units to be removed and replaced while the switchgear is live, without disrupting power to other units, thus enhancing operational efficiency and safety.

Implementation Method 1

U shaped spring-loaded clips

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4082081B1Four pole outgoing plugging assembly
Publication Date: 2023.11.29 ELSTEEL DENMARK
  • EP4082081B1 patent drawingFigure 1
  • EP4082081B1 patent drawingFigure 2A~2B
  • EP4082081B1 patent drawingFigure 2C~3

AI summary

The invention is a plugging assembly comprising a male plug and a matching female plug used to interconnect functional unit and external cables in low-voltage switchgear. Depending on the location of the female plug the invention discloses two variations namely 'side-access' and 'rear-access'. The invention provides facility to connect to external cables with an improved cable protection mechanism. The invention also provides separate connector per phase to wire an indicator on the front cover of the low-voltage switchgear.