Electronic Circuit Breaker Lockout Mechanism for Self-Test Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic circuit breakers lack the ability to self-check before closing main contacts, leading to potential failure in protecting electrical branch circuits if internal components fail, necessitating a mechanism to ensure safe and reliable operation.
Innovation Solution
A circuit breaker design with a lockout mechanism and secondary electrical contact assembly that includes a moveable stop and unlock actuator, allowing the main contact arm to be locked until a self-test is passed, ensuring safe closure of main electrical contacts only when the internal circuit is functioning correctly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lockout mechanism with secondary electrical contacts is added to enable self-check before closing main contacts, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent combines the lockout mechanism and secondary electrical contact assembly into a single integrated unit. The lockout conductor serves dual purposes as both a locking element and an electrical contact carrier, while the spring mechanism provides both mechanical locking force and electrical contact pressure. This merging reduces the number of separate components and simplifies the overall structure despite adding self-check functionality.
Solution Approach 2:
The lockout conductor is designed to perform multiple functions: it acts as a mechanical lock to prevent premature closing, serves as an electrical contact for self-test signaling, and provides structural support for the secondary contact assembly. The spring mechanism similarly provides both locking force and contact pressure. This multi-functionality reduces the need for additional dedicated components.
2Productivity
If the circuit breaker is designed to provide immediate power to the electronic circuit in ON configuration, then productivity is improved, but reliability worsens without self-check capability
Solution Approach 1:
The patent implements preliminary action by performing the self-check test before allowing main contact closure. The secondary electrical contacts close first to energize the electronic circuit and initiate the self-test sequence. Only after successful completion of the self-test does the lockout mechanism release to allow main contacts to close. This preliminary testing ensures reliability while maintaining quick overall operation.
Solution Approach 2:
The closing operation is segmented into two distinct phases: first, the secondary contacts close to provide power for self-test; second, after successful testing, the main contacts close to provide full power. This segmentation allows the system to maintain high productivity by quickly completing the self-test phase while ensuring reliability through the mandatory test-before-close sequence.
3Manufacturing precision
If a moveable stop with non-90 degree angle is used to bias the lockout latch, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent changes the geometric parameter of the moveable stop from a conventional 90-degree angle to a non-90-degree angle. This parameter change creates a mechanical bias that automatically positions the lockout latch in the correct blocking position during the self-test phase. The angled surface provides a deterministic positioning mechanism that improves manufacturing precision by eliminating the need for additional positioning features or adjustment mechanisms.
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
Enables immediate power provision to the electronic circuit in the ON configuration while ensuring a fail-safe condition by preventing main contact closure until a successful self-test, simplifying construction and enhancing reliability by eliminating the need for reopening secondary contacts.
Implementation Method 1
a spring having the moveable secondary electrical contact provided on a moveable portion
Data Source
AI summary
Embodiments provide an electronic circuit breaker subassembly and circuit breaker secondary electrical contact assembly. The circuit breaker secondary electrical contact assembly has a main contact terminal connectable to a main power terminal, a secondary electrical contact set having a stationary secondary electrical contact and a moveable secondary electrical contact, a lockout conductor provided in spring-engaged contact with the main contact terminal on a first end and including one of the stationary or moving secondary electrical contacts on a second end, and a spring having the moveable secondary electrical contact provided on a moveable portion. Circuit breakers and methods of operating the electronic circuit breaker are provided, as are other aspects.