Residual Current Fault Indicator Mechanism for Independent Leakage Signaling

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Solution Overview

Problem

Existing residual-current circuit breakers (RCBOs) lack the ability to distinguish between different types of faults, posing safety hazards when a life-threatening leakage fault occurs, and existing leakage fault indicator mechanisms are complex, complicating production and assembly.

Innovation Solution

A simple leakage fault indicator mechanism for circuit breakers that includes a housing, a rotatably connected handle, a leakage fault tripping member, and a driving assembly with reset elastic elements, allowing independent fault indication without interfering with normal operations, enabling easy assembly and high reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a leakage fault indicator mechanism is added to distinguish fault types, then safety and fault identification capability are improved, but device complexity increases

Engineering Contradiction:
Improvefault identification capabilityVSAvoidindicator mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The indicator mechanism is segmented into independent functional modules: a handle assembly for manual operation, a driving assembly with driving member and driving arm, an indicator assembly with indicator member, and elastic elements for resetting. Each module performs a specific function and can be independently manufactured and assembled, reducing overall system complexity while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The driving assembly serves multiple functions: it transmits rotational motion from the handle to the indicator member for fault indication, and simultaneously transmits motion to the circuit breaker mechanism for tripping. This multi-functionality reduces the need for separate mechanisms, simplifying the overall device structure.

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

2Device complexity

If the indicator mechanism is integrated with the circuit breaker switching function, then structural compactness is improved, but reliability decreases due to potential improper fault indication

Engineering Contradiction:
Improvestructural integrationVSAvoidfault indication accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system is divided into two independent but coordinated subsystems: the indicator mechanism (handle, driving assembly, indicator assembly) and the circuit breaker tripping mechanism. The driving assembly acts as an interface that can independently drive either the indicator or the tripping mechanism based on the fault type, ensuring that fault indication is not contaminated by normal switching operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The driving assembly with its driving member and driving arm serves as an intermediary between the handle operation and the indicator/tripping mechanisms. It selectively transmits motion only when a leakage fault occurs, preventing normal switching operations from triggering false fault indications while maintaining structural integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the indicator mechanism is made as an independent unit, then ease of assembly and production is improved, but device complexity increases

Engineering Contradiction:
Improveassembly convenienceVSAvoidmodular unit complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The indicator mechanism is designed as a complete independent unit containing all necessary components: handle assembly, driving assembly with driving member and driving arm, indicator assembly with indicator member, and elastic elements. This modular design allows the indicator mechanism to be manufactured, tested, and assembled separately from the circuit breaker main body, significantly improving ease of assembly and production while the internal segmentation manages complexity.

Inventive Principle:
Principle #1Segmentation

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 mechanism provides reliable and safe fault indication for leakage faults, ensuring no improper information is transmitted, reducing production complexity, and allowing users to choose the indicator as an independent unit, thereby lowering costs.

Implementation Method 1

a first reset elastic element connected between the indicator and the housing

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4173019B1Residual current fault indicator mechanism and circuit breaker with residual current fault indicator mechanism
Publication Date: 2026.01.07 SIEMENS AG
  • EP4173019B1 patent drawingFigure 1
  • EP4173019B1 patent drawingFigure 2
  • EP4173019B1 patent drawingFigure 3

AI summary

The present invention provides a leakage fault indicator mechanism for a circuit breaker, which comprises an indicator and a driving assembly that is used for leakage fault protection. The indicator is rotatably connected to a housing, and a first reset elastic element is connected between the indicator and the housing. The driving assembly is arranged in the housing, and the driving assembly is switchable to a closed and locked state as driven by a handle. When a leakage fault occurs, the push rod of the leakage fault tripping member unlocks the driving assembly, so that as driven by the driving assembly, the action connecting rod opens the circuit breaker, and as driven by the first reset elastic element, the indicator rotates and indicates the leakage fault. A leakage fault indicator mechanism of the present invention is completely independent of the switching function of a circuit breaker, and may be used as an independent unit of a circuit breaker, having great independence and high reliability. The present invention further provides a circuit breaker with the above-described leakage fault indicator mechanism.