Extraction Tool for Auxiliary Contact Device Removal
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Solution Overview
Problem
In motor control centers, replacing auxiliary contact devices requires removing the entire bucket, leading to system shutdown and increased downtime, as well as safety risks for operators due to the need to access these devices within a closed cabinet.
Innovation Solution
An extraction tool with a handle and securement-engaging portion is used to disengage the auxiliary contact device from the motor starter assembly without removing the bucket, allowing for safe and efficient replacement without shutting down the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the bucket is removed from the MCC cabinet to replace the auxiliary contact device, then the auxiliary contact device can be accessed and replaced, but the overall circuit is terminated and the MCC shuts down
Solution Approach 1:
The invention separates the auxiliary contact device replacement operation from the entire bucket removal operation. By providing a specialized extraction tool that can access and remove only the auxiliary contact device through the existing bucket structure, the system allows maintenance of the contact device without disrupting the entire motor controller unit or terminating the overall circuit.
Solution Approach 2:
The extraction tool acts as an intermediary device that enables access to the auxiliary contact device through the bucket structure without requiring bucket removal. The tool includes a handle portion that extends along the auxiliary contact device and a securement-engaging portion that interacts with the securement member, allowing force application to disengage the contact device while the bucket remains in place.
2Ease of operation
If the bucket is removed from the MCC cabinet to replace the auxiliary contact device, then the auxiliary contact device can be replaced, but the replacement process becomes more complex and time-consuming
Solution Approach 1:
The extraction tool is designed with pre-configured geometric features including a handle portion with specific length and orientation, and a securement-engaging portion shaped to match the securement member geometry. These preliminary design decisions allow the tool to directly engage and remove the auxiliary contact device in a single straightforward motion, eliminating the need for complex disassembly procedures or multiple tool operations.
3Ease of operation
If the operator accesses the auxiliary contact device within the closed cabinet, then the device can be replaced, but the operator is exposed to electrical shock risks
Solution Approach 1:
The extraction tool serves as an intermediary that allows the operator to apply force to the auxiliary contact device through a safe interface. The handle portion extends along the auxiliary contact device, allowing the operator to exert axial force without direct contact with exposed electrical components. The tool's structure mediates between the operator's hand and the electrical components, maintaining electrical isolation while enabling the removal operation.
Data Source
AI summary
A method and associated apparatus are provided for removing an auxiliary contact device from a motor starter assembly engaged with a motor controller unit of a motor control center. The method includes engaging an extraction tool with a securement member operably engaged between the auxiliary contact device and the motor starter assembly. The extraction tool includes a handle portion and a securement-engaging portion. The handle portion extends along the auxiliary contact device for the securement-engaging portion to engage the securement member. The method further includes exerting an axial force on the handle portion such that the handle portion cooperates with the securement-engaging portion to disengage the securement member from between the auxiliary contact device and the motor starter assembly, and to disengage the electrically-conductive engagement between the auxiliary contact device and the motor starter assembly, to remove the auxiliary contact device from the motor starter assembly.