Auxiliary Contact Module Isolation Cavity for Dust Reliability

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Solution Overview

Problem

Auxiliary contacts in electrical systems face reliability issues under dusty operating conditions, particularly in harsh industrial environments, as they are not designed to prevent dust ingress and deposition effectively.

Innovation Solution

An auxiliary contact module with an electrically insulating partition wall that extends across the housing, forming an isolation cavity, and is connected using ultrasonic welding to prevent dust from entering the working space, combined with a movable contact bracket system that allows for easy installation and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If auxiliary contacts are designed for loaded applications (AC-15, DC-13), then they can handle high current inductive loads, but they become sensitive to dust ingress and deposition under dusty operating conditions

Engineering Contradiction:
Improvecurrent handling capabilityVSAvoidperformance under dusty conditions
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The housing is divided into multiple sealed cavities using partition walls, isolating the contact elements from the external dusty environment. This segmentation allows the auxiliary contacts to maintain high current handling capability while protecting the internal working space from dust ingress.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Sealing structures and partition walls act as intermediary barriers between the dusty external environment and the internal contact elements. These intermediaries prevent direct contact between dust particles and the electrical contacts, maintaining reliability without compromising power handling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If auxiliary contacts are used in weak current applications (PLC, VSD, smart buildings), then they can control modern electrical systems, but their reliability becomes critically important in harsh industrial conditions

Engineering Contradiction:
Improveapplication rangeVSAvoidperformance in harsh conditions
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The contact module is divided into isolated cavities that protect sensitive weak current contacts from harsh environmental conditions. This segmentation enables the auxiliary contacts to be adapted for diverse applications (PLC, VSD, smart buildings) while maintaining high reliability through physical isolation from dust and contaminants.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealed cavity design with partition walls provides a cost-effective solution to protect auxiliary contacts. By creating isolated working spaces, the design extends the service life of auxiliary contacts in harsh conditions without requiring expensive special materials or complex protective mechanisms.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If the partition wall is formed integrally with one surface and connected to the other surface, then the structure is simplified, but dust may still intrude through connection interfaces

Engineering Contradiction:
Improvepartition wall structureVSAvoiddust intrusion
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

Ultrasonic welding serves as an intermediary process that creates a seamless, dust-tight connection between the partition wall and housing surfaces. This welding method eliminates gaps and interfaces where dust could penetrate, while maintaining the simplified integral structure of the partition wall.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Traditional mechanical fastening methods (screws, clips, adhesives) are replaced with ultrasonic welding, which uses high-frequency mechanical vibrations to melt and fuse the plastic materials. This substitution creates a homogeneous, gap-free joint that completely prevents dust intrusion while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 effectively prevents dust intrusion into the contact module's working space, enhancing the reliability and performance of auxiliary contacts in dusty conditions, especially in weak current applications.

Implementation Method 1

an electrically insulating partition wall which extends across opposite surfaces of the housing and defines a closed cavity together with a portion of the opposite surfaces of the housing

Methodology Applied
Scientific EffectPhysical barrier: Physical Containment

Implementation Method 2

the partition wall (18) is formed integrally with one (11) of the opposite surfaces, and is connected to the other (12) of the opposite surfaces by ultrasonic welding

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP3846191B1Auxiliary contact module, contactor assembly and electrical cabinet
Publication Date: 2023.10.04 SCHNEIDER ELECTRIC IND SAS
  • EP3846191B1 patent drawingFigure 1~2
  • EP3846191B1 patent drawingFigure 3~4
  • EP3846191B1 patent drawingFigure 5

AI summary

An auxiliary contact module is disclosed. The auxiliary contact module comprises: a housing; a static contact secured in the housing, the static contact comprises a static contact; a movable contact, comprises a movable contact, the movable contact mounted on a movable contact bracket, wherein the movable contact bracket is movably disposed in the housing to move between a closed position and an open position; wherein the auxiliary contact module further comprises an electrically insulating partition wall which extends across the opposite surfaces of the housing and defines a closed cavity together with a portion of the opposite surface of the housing, wherein the static contact extends into the cavity so that the static contact is disposed in the cavity, and the movable contact and the movable contact bracket are disposed in the cavity. A contactor assembly and an electrical cabinet are also disclosed. By using the partition wall to accommodate the working space of the auxiliary contact in the isolation cavity, dust can be fully prevented from invading the working space, and the reliability of the module is improved.