Magnetic Trip Device with Automatic Reset and Fault Latch
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Solution Overview
Problem
Conventional magnetic trip devices for circuit breakers lack means to maintain fault information indicating until the cause of an accident is removed, pose risks during reactivation, and lack automatic reset mechanisms for actuator coil parts, leading to potential electrical safety accidents.
Innovation Solution
A magnetic trip device with an automatic reset mechanism that initializes the actuator coil part's position and maintains fault information indication independently until manual initialization, featuring a driving lever latch, automatic reset mechanism, and avoiding portions to prevent interference and ensure safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional magnetic trip device is used, then the circuit breaker can perform basic trip operation, but there is no means to maintain fault information indicating until cause of accident is removed
Solution Approach 1:
The microswitch is integrated within the trip mechanism structure, with its actuating arm nested in the path of the trip solenoid plunger. The latch lever is positioned within the trip device assembly, engaging with the lockout lever. This nested arrangement allows fault information maintenance functionality to be incorporated without significantly increasing external device complexity.
Solution Approach 2:
The microswitch acts as an intermediary element between the trip solenoid plunger and the fault indication system. When the plunger moves during tripping, it actuates the microswitch which then maintains the fault indication state. This intermediary mechanism enables reliable fault information maintenance while keeping the overall trip device structure manageable.
2Reliability
If conventional magnetic trip device is used, then basic trip operation is achieved, but there is risk of serious electrical safety accident when circuit breaker is operated to closed position prior to eliminating cause of accident
Solution Approach 1:
The latch lever is pre-configured to engage with the lockout lever and prevent the trip solenoid plunger from returning to its retracted position during a fault condition. This preliminary anti-action mechanism blocks any attempt to close the circuit breaker when fault information is indicating, thereby preventing electrical safety accidents before they can occur.
Solution Approach 2:
The microswitch provides feedback about the trip state to the indication system. When tripping occurs, the microswitch actuates and maintains the fault indication visible to the operator. This feedback loop ensures that the operator is continuously informed of the fault condition and cannot inadvertently reset the breaker until the fault is cleared and the indication is reset.
3Extent of automation
If conventional magnetic trip device is used, then trip operation functions, but there is no automatic reset means to initialize actuator coil part position in conjunction with main switching shaft
Solution Approach 1:
The automatic reset function is merged with the existing main switching shaft mechanism. The latch lever is positioned to engage with the lockout lever in a way that automatically resets the actuator coil part position when the main switching shaft completes its rotation during normal operation. This combining of functions allows automatic reset capability to be achieved without adding a completely separate reset mechanism, thereby limiting the increase in device complexity.
4Reliability
If conventional magnetic trip device is used, then basic operation is achieved, but there is no means to maintain fault information indicating independently of magnetic trip device return operation
Solution Approach 1:
The fault information maintenance function is segmented from the magnetic trip device return operation. The microswitch is positioned to be actuated by the trip solenoid plunger movement, but its latched state is maintained independently by the latch lever mechanism. This segmentation allows the fault indication to persist and be maintained independently of subsequent return operations of the magnetic trip device components.
Solution Approach 2:
The latch lever provides a dynamic locking mechanism that maintains the microswitch in its actuated state regardless of subsequent movements of the trip solenoid plunger or other magnetic trip device components. The latch lever can be dynamically engaged or disengaged, allowing the fault information to be maintained independently until manually reset, while still permitting controlled resetting when appropriate.
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
Ensures electrical safety by maintaining trip indications until causes are resolved and automatically resetting for next operations, preventing accidental reactivation and enhancing operational reliability.
Implementation Method 1
a plunger 21a configured to move to an advanced position or a retracted position according to magnetization or demagnetization of the coil
Implementation Method 2
move an advanced position or retracted position according to magnetization or demagnetization of the coil
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A magnetic trip device according to the present disclosure comprises an actuator coil part (21) having a plunger (21a); an output plate (22) configured to rotate in a first direction by the pressing of the plunger (21a); a micro switch (28) configured to output an electrical signal indicating a state of the circuit breaker; a switch driving lever mechanism (26, 27) configured to rotate to a first position for pressing the operation lever portion and a second position for releasing the operation lever portion; a driving lever bias spring (32) for elastically pressing the switch driving lever mechanism; an automatic reset mechanism (23) for pressing the plunger to the retracted position; a driving lever latch (29) configured to rotate to a restraining position for preventing the switch driving lever mechanism from rotating to the first position, and a release position; and an avoiding portion formed on the output plate to avoid contacting with the switch driving lever mechanism.