Replaceable Circuit Breaker With Interlock Safety Under Load
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Solution Overview
Problem
Existing electrical protection devices, such as circuit breakers, require de-energization of circuits to safely install or remove them, which can be inconvenient and unsafe, especially when working under load conditions.
Innovation Solution
A system utilizing interlocks, detents, and poka-yokes that allows for safe installation and removal of electrical protection devices under load by requiring a specific sequence of assembly and disassembly, ensuring that the device is either in a tripped state or properly aligned to prevent electrical connections and facilitate safe handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circuit breakers require de-energization for safe installation/removal, then safety is improved, but productivity and convenience deteriorate
Solution Approach 1:
The circuit breaker is pre-configured with interlock mechanisms and movable contacts that automatically engage safety features before installation. The device requires preliminary alignment in a specific orientation where contacts are retracted or shielded, ensuring safety is built into the installation process itself rather than requiring separate de-energization steps
Solution Approach 2:
The circuit breaker performs self-protection through automatic tripping mechanisms and interlocks that engage when the device is improperly oriented or under load. The movable contacts automatically disconnect when the breaker is removed from the panel, providing self-service safety without requiring manual de-energization of the entire circuit
2Productivity
If circuit breakers can be installed/removed under load, then productivity is improved, but safety deteriorates
Solution Approach 1:
Movable contacts act as an intermediary mechanism between the circuit breaker terminals and the electrical circuit. These contacts can be positioned to either connect or disconnect the circuit breaker from the circuit, providing a controlled transition state that allows installation/removal under load while preventing direct exposure to electrical hazards
Solution Approach 2:
The circuit breaker is designed with terminals and contacts that are pre-positioned in a safe, disconnected state during installation. The interlock mechanisms ensure that electrical connections are only made after the breaker is properly seated and oriented, preliminarily establishing safe conditions before full electrical engagement occurs
3Reliability
If interlock mechanisms are added to prevent installation under load, then safety is improved, but device complexity increases
Solution Approach 1:
The interlock mechanisms are merged with the existing structural components of the circuit breaker, such as the mounting ears, terminals, and housing features. Rather than adding separate, independent interlock devices, the safety features are integrated into the breaker's own structure, reducing overall complexity while maintaining safety functionality
Solution Approach 2:
The circuit breaker is segmented into functional modules including movable contacts, interlock features, and terminal sections that can independently perform their safety functions. This segmentation allows each component to be simple in design while the combination provides comprehensive safety, avoiding the need for a single complex interlock mechanism
Data Source
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AI summary
The present disclosure relates to an electrical protection system, including a breaker enclosure and associated terminals, and the methods of use therefor that allow for a circuit breaker or other electrical protection device to be safely added or removed from a circuit while power is supplied to at least one of the terminals. The disclosed enclosure and terminals include a series of interrelated safety features that prevent a user from accidentally completing the circuit from one terminal to another when the electrical protection system would be in an unsafe state. The combination of features described herein allow for a replaceable electrical protection device for equipment under load to be realized, thus improving user safety.