Transient Overvoltage Protection Device Modular Base Assembly

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Solution Overview

Problem

Existing self-protected electrical assemblies face challenges with rigid wires that are expensive and difficult to position accurately, leading to residual overvoltages and non-compliance with standards due to suboptimal wiring lengths and complexities in production and assembly.

Innovation Solution

A protective device with a base that reduces wire length, allows precise positioning, and uses flexible wires, featuring a modular interface and wire cover casing to simplify wiring and comply with standards, while maintaining wire protection and facilitating assembly with a circuit breaker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If rigid wires are used for wiring between the protection device and circuit breaker, then the wiring structure is stable, but the cost increases and positioning precision deteriorates

Engineering Contradiction:
Improvewiring structure stabilityVSAvoidwire positioning precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The base is divided into multiple compartments, each dedicated to holding specific wires. This segmentation provides structured guidance for wire routing, improving positioning precision while maintaining structural stability through the organized layout.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base acts as an intermediary component between the protection device and circuit breaker, providing a standardized interface with pre-defined wire exit positions. This mediator role enables precise wire positioning without requiring rigid wires, as the base structure itself ensures proper alignment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the length of electric wires is increased to facilitate wiring, then ease of operation improves, but residual overvoltages appear that are harmful to the assembly

Engineering Contradiction:
Improvewiring easeVSAvoidresidual overvoltages
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The base is designed with pre-defined wire exit positions and compartments that guide wire routing before the wiring operation begins. This preliminary structuring enables workers to perform wiring easily while ensuring wire length remains optimized, preventing residual overvoltages.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If a complex support and cover arrangement is used to hold conductive elements, then wire protection improves, but device complexity and production complexity increase

Engineering Contradiction:
Improvewire protection from external damageVSAvoidsupport and cover arrangement complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The base integrates multiple functions into a single component: it provides structural support, contains compartments for wire organization, and offers protection for the wiring. This merging eliminates the need for separate support structures and covers, reducing device complexity while maintaining comprehensive wire protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The base serves multiple purposes simultaneously: mechanical support for the protection device, wire routing guide, wire protection enclosure, and positioning element for the circuit breaker assembly. This multi-functionality reduces the overall number of components needed in the assembly.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reduces residual overvoltages, complies with French standard NF 15/100, and enhances productivity by using flexible wires and a modular design that simplifies the assembly process and protects wires from external damage.

Implementation Method 1

housing at least one varistor associated with a thermal disconnection device

Methodology Applied
Scientific EffectVaristor non-linear resistance: Electrical Resistance

Implementation Method 2

a spark gap as well as wires, respectively connected to each varistor and to the spark gap

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentEP2897151B1Protection device against temporary overvoltages and self-protected electrical assembly comprising such a protection device assembled with a circuit breaker
Publication Date: 2019.03.13 LEGRAND FRANCE SA
  • EP2897151B1 patent drawingFigure 1~2
  • EP2897151B1 patent drawingFigure 3~4
  • EP2897151B1 patent drawingFigure 5~6

AI summary

The invention relates to a protective device (300) against transient overvoltages, particularly those of atmospheric origin, comprising a housing (310) containing at least one varistor associated with a thermal disconnect device, a spark gap, and electrical wires (F1, F2, F3, FN) respectively connected to each varistor and to the spark gap, a portion of said electrical wires emerging outside the housing for connection to the terminals of a circuit breaker. According to the invention, the protective device comprises, outside the housing, a base (410) made of electrically insulating material, separate from said housing and provided, on the one hand, with retaining means cooperating with said electrical wires to hold each electrical wire in a determined position, and, on the other hand, with mounting means (415, 415A, 417, 417A) for attaching said base to the circuit breaker.The invention also relates to a self-protected electrical assembly comprising a protective device as mentioned above and a circuit breaker assembled together by one of their main lateral faces.