Installation Switchgear Single Contact Point Segmentation

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Solution Overview

Problem

Existing installation switching devices face challenges in achieving a compact design while meeting regulatory requirements and ensuring easy installation and high switching accuracy.

Innovation Solution

The design incorporates a single contact point with a fixed and movable contact piece, a flexible phase connection rail, and a compact arrangement of components such as the current-limiting resistor and thermal bimetal, allowing for improved heat dissipation and space efficiency, along with a vented arc quenching chamber for enhanced dielectric strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a double contact point is used for the main contact point, then the switching reliability is improved, but the device complexity and housing space increase

Engineering Contradiction:
Improveswitching reliabilityVSAvoidcontact point structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The main contact point is segmented into a fixed contact piece and a movable contact piece that are spatially separated and mechanically independent. The movable contact piece is mounted on a pivotable contact lever that rotates around a stationary axis, creating distinct functional zones for current flow and mechanical actuation. This segmentation maintains reliable switching while simplifying the overall structure compared to a double contact point design.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If more components are arranged in the housing, then the device functionality is improved, but the external dimensions increase

Engineering Contradiction:
Improvedevice functionalityVSAvoidhousing volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The phase connection bar is extended in the longitudinal dimension of the housing, running parallel to the broad side and connecting to the input terminal via a flexible conductor. This longitudinal arrangement allows the bar to span the housing length without increasing width or height, accommodating busbar connections while maintaining a compact cross-sectional profile that fits standard mounting spaces.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The current-limiting resistor is nested within a dedicated partial housing area that is delimited by dividing walls, creating a compact nested structure. The resistor is positioned in a recessed zone that utilizes otherwise wasted space in the housing, allowing it to be integrated without increasing the external dimensions of the device.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Volume of stationary object

If the current-limiting resistor is placed near the arc quenching chamber, then the housing space is saved, but the resistor is exposed to arc effects

Engineering Contradiction:
Improvehousing space utilizationVSAvoidarc exposure to resistor
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The housing interior is segmented into distinct functional zones using dividing walls. The current-limiting resistor is placed in a dedicated partial housing area that is spatially separated from the arc quenching chamber by these dividing walls. This segmentation creates a physical barrier that protects the resistor from arc exposure while maintaining compact overall housing dimensions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Dividing walls act as intermediary structures that separate the arc quenching chamber from the current-limiting resistor housing area. These walls serve as protective barriers that prevent direct arc exposure to the resistor while allowing the housing to maintain a compact, space-efficient design by utilizing the vertical and lateral space effectively.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If the main contact lever is fixed without a stationary axis bearing, then the device complexity is reduced, but the switching accuracy and service life decrease

Engineering Contradiction:
Improvecontact lever mounting structureVSAvoidswitching accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The stationary axis bearing serves the dual function of supporting the movable contact piece while maintaining its precise positional relationship with the fixed contact piece. The bearing structure is integrated into the housing and automatically maintains the correct geometry without requiring external adjustment mechanisms, achieving both simplicity and high switching accuracy through self-contained functional design.

Inventive Principle:
Principle #25Self-service

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 configuration results in a more compact, easy-to-install device with increased switching accuracy and service life, while meeting regulatory standards for space and performance.

Implementation Method 1

a main thermal bimetallic strip, which acts on a switching mechanism with a latching point

Methodology Applied
Scientific EffectThermal bimetallic effect: Bi-Metallic Strip

Implementation Method 2

a main thermal bimetallic strip

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

a vented arc quenching chamber for enhanced dielectric strength

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 4

allowing for improved heat dissipation

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2143122B1Installation switchgear
Publication Date: 2011.10.12 ABB AG(DE)
  • EP2143122B1 patent drawingFigure 1
  • EP2143122B1 patent drawingFigure 2
  • EP2143122B1 patent drawingFigure 3

AI summary

The invention relates to an installation switchgear, particularly a selective protective switch, having a housing comprising a mounting side, a front and rear face, and wide as well as front and rear narrow sides connecting the mounting side and the face, having a main current path extending between an input terminal and an output terminal, the main current path comprising a main contact point equipped with an arc quenching chamber, a striker armature system bringing the main contact point into the open position, and a main thermal bimetal, which acts on a switching mechanism having a locking position such that the contact point remains permanently open, having a secondary current path in which a current limiting resistor, a selective thermal bimetal also acting on the switching mechanism, and a separating contact point to be opened by the switching mechanism are disposed, and having a handle, by means of which the main contact point can be opened and closed via the switching mechanism, characterized in that a) the secondary current path is switched in parallel to the series connection of the first bimetal via the main contact point, b) the main contact point is configured as a single contact point having a fixed and a movable contact piece, and c) a phase terminal bar extending close to the mounting side and approximately parallel to the same is provided in the housing interior and connected to the input terminal, on the free end of which a clamping contact protruding from the housing on the mounting side is attached in an installation splitter for clamping to bus bars.